linux: Add cgroups patches for 4.9, 4.10, 4.11

2017-05-02 08:49:39 -04:00 · 2017-05-02 08:49:39 -04:00 · b5169fd277
commit b5169fd277
parent d7501b986a
6 changed files with 2355 additions and 824 deletions
--- a/pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/4.10.patch
+++ b/pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/4.10.patch
@ -0,0 +1,784 @@
+commit d0273888226b264d34795970c073d6e935d5114f
+Author: Tejun Heo <tj@kernel.org>
+Date:   Fri Mar 11 07:31:23 2016 -0500
+
+    sched: Misc preps for cgroup unified hierarchy interface
+    
+    Make the following changes in preparation for the cpu controller
+    interface implementation for the unified hierarchy.  This patch
+    doesn't cause any functional differences.
+    
+    * s/cpu_stats_show()/cpu_cfs_stats_show()/
+    
+    * s/cpu_files/cpu_legacy_files/
+    
+    * Separate out cpuacct_stats_read() from cpuacct_stats_show().  While
+      at it, make the @val array u64 for consistency.
+    
+    Signed-off-by: Tejun Heo <tj@kernel.org>
+    Cc: Ingo Molnar <mingo@redhat.com>
+    Cc: Peter Zijlstra <peterz@infradead.org>
+    Cc: Li Zefan <lizefan@huawei.com>
+    Cc: Johannes Weiner <hannes@cmpxchg.org>
+
+diff --git a/kernel/sched/core.c b/kernel/sched/core.c
+index c56fb57f2991..112037890e9b 100644
+--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
+@@ -8724,7 +8724,7 @@ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
+ 	return ret;
+ }
+ 
+-static int cpu_stats_show(struct seq_file *sf, void *v)
+static int cpu_cfs_stats_show(struct seq_file *sf, void *v)
+ {
+ 	struct task_group *tg = css_tg(seq_css(sf));
+ 	struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+@@ -8764,7 +8764,7 @@ static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css,
+ }
+ #endif /* CONFIG_RT_GROUP_SCHED */
+ 
+-static struct cftype cpu_files[] = {
+static struct cftype cpu_legacy_files[] = {
+ #ifdef CONFIG_FAIR_GROUP_SCHED
+ 	{
+ 		.name = "shares",
+@@ -8785,7 +8785,7 @@ static struct cftype cpu_files[] = {
+ 	},
+ 	{
+ 		.name = "stat",
+-		.seq_show = cpu_stats_show,
+		.seq_show = cpu_cfs_stats_show,
+ 	},
+ #endif
+ #ifdef CONFIG_RT_GROUP_SCHED
+@@ -8810,7 +8810,7 @@ struct cgroup_subsys cpu_cgrp_subsys = {
+ 	.fork		= cpu_cgroup_fork,
+ 	.can_attach	= cpu_cgroup_can_attach,
+ 	.attach		= cpu_cgroup_attach,
+-	.legacy_cftypes	= cpu_files,
+	.legacy_cftypes	= cpu_legacy_files,
+ 	.early_init	= true,
+ };
+ 
+diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
+index 9add206b5608..4dd7b8588b69 100644
+--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
+@@ -276,26 +276,33 @@ static int cpuacct_all_seq_show(struct seq_file *m, void *V)
+ 	return 0;
+ }
+ 
+-static int cpuacct_stats_show(struct seq_file *sf, void *v)
+static void cpuacct_stats_read(struct cpuacct *ca,
+			       u64 (*val)[CPUACCT_STAT_NSTATS])
+ {
+-	struct cpuacct *ca = css_ca(seq_css(sf));
+-	s64 val[CPUACCT_STAT_NSTATS];
+ 	int cpu;
+-	int stat;
+ 
+-	memset(val, 0, sizeof(val));
+	memset(val, 0, sizeof(*val));
+
+ 	for_each_possible_cpu(cpu) {
+ 		u64 *cpustat = per_cpu_ptr(ca->cpustat, cpu)->cpustat;
+ 
+-		val[CPUACCT_STAT_USER]   += cpustat[CPUTIME_USER];
+-		val[CPUACCT_STAT_USER]   += cpustat[CPUTIME_NICE];
+-		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SYSTEM];
+-		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_IRQ];
+-		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SOFTIRQ];
+		(*val)[CPUACCT_STAT_USER]   += cpustat[CPUTIME_USER];
+		(*val)[CPUACCT_STAT_USER]   += cpustat[CPUTIME_NICE];
+		(*val)[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SYSTEM];
+		(*val)[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_IRQ];
+		(*val)[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SOFTIRQ];
+ 	}
+}
+
+static int cpuacct_stats_show(struct seq_file *sf, void *v)
+{
+	u64 val[CPUACCT_STAT_NSTATS];
+	int stat;
+
+	cpuacct_stats_read(css_ca(seq_css(sf)), &val);
+ 
+ 	for (stat = 0; stat < CPUACCT_STAT_NSTATS; stat++) {
+-		seq_printf(sf, "%s %lld\n",
+		seq_printf(sf, "%s %llu\n",
+ 			   cpuacct_stat_desc[stat],
+ 			   (long long)cputime64_to_clock_t(val[stat]));
+ 	}
+
+commit 41103511fa43b4aa04fea259c5c60fef752ddefb
+Author: Tejun Heo <tj@kernel.org>
+Date:   Fri Mar 11 07:31:23 2016 -0500
+
+    sched: Implement interface for cgroup unified hierarchy
+    
+    While the cpu controller doesn't have any functional problems, there
+    are a couple interface issues which can be addressed in the v2
+    interface.
+    
+    * cpuacct being a separate controller.  This separation is artificial
+      and rather pointless as demonstrated by most use cases co-mounting
+      the two controllers.  It also forces certain information to be
+      accounted twice.
+    
+    * Use of different time units.  Writable control knobs use
+      microseconds, some stat fields use nanoseconds while other cpuacct
+      stat fields use centiseconds.
+    
+    * Control knobs which can't be used in the root cgroup still show up
+      in the root.
+    
+    * Control knob names and semantics aren't consistent with other
+      controllers.
+    
+    This patchset implements cpu controller's interface on the unified
+    hierarchy which adheres to the controller file conventions described
+    in Documentation/cgroups/unified-hierarchy.txt.  Overall, the
+    following changes are made.
+    
+    * cpuacct is implictly enabled and disabled by cpu and its information
+      is reported through "cpu.stat" which now uses microseconds for all
+      time durations.  All time duration fields now have "_usec" appended
+      to them for clarity.  While this doesn't solve the double accounting
+      immediately, once majority of users switch to v2, cpu can directly
+      account and report the relevant stats and cpuacct can be disabled on
+      the unified hierarchy.
+    
+      Note that cpuacct.usage_percpu is currently not included in
+      "cpu.stat".  If this information is actually called for, it can be
+      added later.
+    
+    * "cpu.shares" is replaced with "cpu.weight" and operates on the
+      standard scale defined by CGROUP_WEIGHT_MIN/DFL/MAX (1, 100, 10000).
+      The weight is scaled to scheduler weight so that 100 maps to 1024
+      and the ratio relationship is preserved - if weight is W and its
+      scaled value is S, W / 100 == S / 1024.  While the mapped range is a
+      bit smaller than the orignal scheduler weight range, the dead zones
+      on both sides are relatively small and covers wider range than the
+      nice value mappings.  This file doesn't make sense in the root
+      cgroup and isn't create on root.
+    
+    * "cpu.cfs_quota_us" and "cpu.cfs_period_us" are replaced by "cpu.max"
+      which contains both quota and period.
+    
+    * "cpu.rt_runtime_us" and "cpu.rt_period_us" are replaced by
+      "cpu.rt.max" which contains both runtime and period.
+    
+    v2: cpu_stats_show() was incorrectly using CONFIG_FAIR_GROUP_SCHED for
+        CFS bandwidth stats and also using raw division for u64.  Use
+        CONFIG_CFS_BANDWITH and do_div() instead.
+    
+        The semantics of "cpu.rt.max" is not fully decided yet.  Dropped
+        for now.
+    
+    Signed-off-by: Tejun Heo <tj@kernel.org>
+    Cc: Ingo Molnar <mingo@redhat.com>
+    Cc: Peter Zijlstra <peterz@infradead.org>
+    Cc: Li Zefan <lizefan@huawei.com>
+    Cc: Johannes Weiner <hannes@cmpxchg.org>
+
+diff --git a/kernel/sched/core.c b/kernel/sched/core.c
+index 112037890e9b..a80d586a4317 100644
+--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
+@@ -8803,6 +8803,139 @@ static struct cftype cpu_legacy_files[] = {
+ 	{ }	/* terminate */
+ };
+ 
+static int cpu_stats_show(struct seq_file *sf, void *v)
+{
+	cpuacct_cpu_stats_show(sf);
+
+#ifdef CONFIG_CFS_BANDWIDTH
+	{
+		struct task_group *tg = css_tg(seq_css(sf));
+		struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+		u64 throttled_usec;
+
+		throttled_usec = cfs_b->throttled_time;
+		do_div(throttled_usec, NSEC_PER_USEC);
+
+		seq_printf(sf, "nr_periods %d\n"
+			   "nr_throttled %d\n"
+			   "throttled_usec %llu\n",
+			   cfs_b->nr_periods, cfs_b->nr_throttled,
+			   throttled_usec);
+	}
+#endif
+	return 0;
+}
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static u64 cpu_weight_read_u64(struct cgroup_subsys_state *css,
+			       struct cftype *cft)
+{
+	struct task_group *tg = css_tg(css);
+	u64 weight = scale_load_down(tg->shares);
+
+	return DIV_ROUND_CLOSEST_ULL(weight * CGROUP_WEIGHT_DFL, 1024);
+}
+
+static int cpu_weight_write_u64(struct cgroup_subsys_state *css,
+				struct cftype *cftype, u64 weight)
+{
+	/*
+	 * cgroup weight knobs should use the common MIN, DFL and MAX
+	 * values which are 1, 100 and 10000 respectively.  While it loses
+	 * a bit of range on both ends, it maps pretty well onto the shares
+	 * value used by scheduler and the round-trip conversions preserve
+	 * the original value over the entire range.
+	 */
+	if (weight < CGROUP_WEIGHT_MIN || weight > CGROUP_WEIGHT_MAX)
+		return -ERANGE;
+
+	weight = DIV_ROUND_CLOSEST_ULL(weight * 1024, CGROUP_WEIGHT_DFL);
+
+	return sched_group_set_shares(css_tg(css), scale_load(weight));
+}
+#endif
+
+static void __maybe_unused cpu_period_quota_print(struct seq_file *sf,
+						  long period, long quota)
+{
+	if (quota < 0)
+		seq_puts(sf, "max");
+	else
+		seq_printf(sf, "%ld", quota);
+
+	seq_printf(sf, " %ld\n", period);
+}
+
+/* caller should put the current value in *@periodp before calling */
+static int __maybe_unused cpu_period_quota_parse(char *buf,
+						 u64 *periodp, u64 *quotap)
+{
+	char tok[21];	/* U64_MAX */
+
+	if (!sscanf(buf, "%s %llu", tok, periodp))
+		return -EINVAL;
+
+	*periodp *= NSEC_PER_USEC;
+
+	if (sscanf(tok, "%llu", quotap))
+		*quotap *= NSEC_PER_USEC;
+	else if (!strcmp(tok, "max"))
+		*quotap = RUNTIME_INF;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+#ifdef CONFIG_CFS_BANDWIDTH
+static int cpu_max_show(struct seq_file *sf, void *v)
+{
+	struct task_group *tg = css_tg(seq_css(sf));
+
+	cpu_period_quota_print(sf, tg_get_cfs_period(tg), tg_get_cfs_quota(tg));
+	return 0;
+}
+
+static ssize_t cpu_max_write(struct kernfs_open_file *of,
+			     char *buf, size_t nbytes, loff_t off)
+{
+	struct task_group *tg = css_tg(of_css(of));
+	u64 period = tg_get_cfs_period(tg);
+	u64 quota;
+	int ret;
+
+	ret = cpu_period_quota_parse(buf, &period, &quota);
+	if (!ret)
+		ret = tg_set_cfs_bandwidth(tg, period, quota);
+	return ret ?: nbytes;
+}
+#endif
+
+static struct cftype cpu_files[] = {
+	{
+		.name = "stat",
+		.flags = CFTYPE_NOT_ON_ROOT,
+		.seq_show = cpu_stats_show,
+	},
+#ifdef CONFIG_FAIR_GROUP_SCHED
+	{
+		.name = "weight",
+		.flags = CFTYPE_NOT_ON_ROOT,
+		.read_u64 = cpu_weight_read_u64,
+		.write_u64 = cpu_weight_write_u64,
+	},
+#endif
+#ifdef CONFIG_CFS_BANDWIDTH
+	{
+		.name = "max",
+		.flags = CFTYPE_NOT_ON_ROOT,
+		.seq_show = cpu_max_show,
+		.write = cpu_max_write,
+	},
+#endif
+	{ }	/* terminate */
+};
+
+ struct cgroup_subsys cpu_cgrp_subsys = {
+ 	.css_alloc	= cpu_cgroup_css_alloc,
+ 	.css_released	= cpu_cgroup_css_released,
+@@ -8811,7 +8944,15 @@ struct cgroup_subsys cpu_cgrp_subsys = {
+ 	.can_attach	= cpu_cgroup_can_attach,
+ 	.attach		= cpu_cgroup_attach,
+ 	.legacy_cftypes	= cpu_legacy_files,
+	.dfl_cftypes	= cpu_files,
+ 	.early_init	= true,
+#ifdef CONFIG_CGROUP_CPUACCT
+	/*
+	 * cpuacct is enabled together with cpu on the unified hierarchy
+	 * and its stats are reported through "cpu.stat".
+	 */
+	.depends_on	= 1 << cpuacct_cgrp_id,
+#endif
+ };
+ 
+ #endif	/* CONFIG_CGROUP_SCHED */
+diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
+index 4dd7b8588b69..97c6dd7d8f59 100644
+--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
+@@ -347,6 +347,31 @@ static struct cftype files[] = {
+ 	{ }	/* terminate */
+ };
+ 
+/* used to print cpuacct stats in cpu.stat on the unified hierarchy */
+void cpuacct_cpu_stats_show(struct seq_file *sf)
+{
+	struct cgroup_subsys_state *css;
+	u64 usage, val[CPUACCT_STAT_NSTATS];
+
+	css = cgroup_get_e_css(seq_css(sf)->cgroup, &cpuacct_cgrp_subsys);
+
+	usage = cpuusage_read(css, seq_cft(sf));
+	cpuacct_stats_read(css_ca(css), &val);
+
+	val[CPUACCT_STAT_USER] *= TICK_NSEC;
+	val[CPUACCT_STAT_SYSTEM] *= TICK_NSEC;
+	do_div(usage, NSEC_PER_USEC);
+	do_div(val[CPUACCT_STAT_USER], NSEC_PER_USEC);
+	do_div(val[CPUACCT_STAT_SYSTEM], NSEC_PER_USEC);
+
+	seq_printf(sf, "usage_usec %llu\n"
+		   "user_usec %llu\n"
+		   "system_usec %llu\n",
+		   usage, val[CPUACCT_STAT_USER], val[CPUACCT_STAT_SYSTEM]);
+
+	css_put(css);
+}
+
+ /*
+  * charge this task's execution time to its accounting group.
+  *
+diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h
+index ba72807c73d4..ddf7af466d35 100644
+--- a/kernel/sched/cpuacct.h
+++ b/kernel/sched/cpuacct.h
+@@ -2,6 +2,7 @@
+ 
+ extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
+ extern void cpuacct_account_field(struct task_struct *tsk, int index, u64 val);
+extern void cpuacct_cpu_stats_show(struct seq_file *sf);
+ 
+ #else
+ 
+@@ -14,4 +15,8 @@ cpuacct_account_field(struct task_struct *tsk, int index, u64 val)
+ {
+ }
+ 
+static inline void cpuacct_cpu_stats_show(struct seq_file *sf)
+{
+}
+
+ #endif
+
+commit 2dae6b0ec091c93131e02eb56987ec6c26818f42
+Author: Tejun Heo <tj@kernel.org>
+Date:   Fri Aug 5 12:41:01 2016 -0400
+
+    cgroup: add documentation regarding CPU controller cgroup v2 support
+    
+    Signed-off-by: Tejun Heo <tj@kernel.org>
+
+diff --git a/Documentation/cgroup-v2-cpu.txt b/Documentation/cgroup-v2-cpu.txt
+new file mode 100644
+index 000000000000..1ed7032d4472
+--- /dev/null
+++ b/Documentation/cgroup-v2-cpu.txt
+@@ -0,0 +1,368 @@
+
+
+CPU Controller on Control Group v2
+
+August, 2016		Tejun Heo <tj@kernel.org>
+
+
+While most controllers have support for cgroup v2 now, the CPU
+controller support is not upstream yet due to objections from the
+scheduler maintainers on the basic designs of cgroup v2.  This
+document explains the current situation as well as an interim
+solution, and details the disagreements and arguments.  The latest
+version of this document can be found at the following URL.
+
+ https://git.kernel.org/cgit/linux/kernel/git/tj/cgroup.git/tree/Documentation/cgroup-v2-cpu.txt?h=cgroup-v2-cpu
+
+This document was posted to the linux-kernel and cgroup mailing lists.
+Unfortunately, no consensus was reached as of Oct, 2016.  The thread
+can be found at the following URL.
+
+ http://lkml.kernel.org/r/20160805170752.GK2542@mtj.duckdns.org
+
+
+CONTENTS
+
+1. Current Situation and Interim Solution
+2. Disagreements and Arguments
+  2-1. Contentious Restrictions
+    2-1-1. Process Granularity
+    2-1-2. No Internal Process Constraint
+  2-2. Impact on CPU Controller
+    2-2-1. Impact of Process Granularity
+    2-2-2. Impact of No Internal Process Constraint
+  2-3. Arguments for cgroup v2
+3. Way Forward
+4. References
+
+
+1. Current Situation and Interim Solution
+
+All objections from the scheduler maintainers apply to cgroup v2 core
+design, and there are no known objections to the specifics of the CPU
+controller cgroup v2 interface.  The only blocked part is changes to
+expose the CPU controller interface on cgroup v2, which comprises the
+following two patches:
+
+ [1] sched: Misc preps for cgroup unified hierarchy interface
+ [2] sched: Implement interface for cgroup unified hierarchy
+
+The necessary changes are superficial and implement the interface
+files on cgroup v2.  The combined diffstat is as follows.
+
+ kernel/sched/core.c    |  149 +++++++++++++++++++++++++++++++++++++++++++++++--
+ kernel/sched/cpuacct.c |   57 ++++++++++++------
+ kernel/sched/cpuacct.h |    5 +
+ 3 files changed, 189 insertions(+), 22 deletions(-)
+
+The patches are easy to apply and forward-port.  The following git
+branch will always carry the two patches on top of the latest release
+of the upstream kernel.
+
+ git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git/cgroup-v2-cpu
+
+There also are versioned branches going back to v4.4.
+
+ git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git/cgroup-v2-cpu-$KERNEL_VER
+
+While it's difficult to tell whether the CPU controller support will
+be merged, there are crucial resource control features in cgroup v2
+that are only possible due to the design choices that are being
+objected to, and every effort will be made to ease enabling the CPU
+controller cgroup v2 support out-of-tree for parties which choose to.
+
+
+2. Disagreements and Arguments
+
+There have been several lengthy discussion threads [3][4] on LKML
+around the structural constraints of cgroup v2.  The two that affect
+the CPU controller are process granularity and no internal process
+constraint.  Both arise primarily from the need for common resource
+domain definition across different resources.
+
+The common resource domain is a powerful concept in cgroup v2 that
+allows controllers to make basic assumptions about the structural
+organization of processes and controllers inside the cgroup hierarchy,
+and thus solve problems spanning multiple types of resources.  The
+prime example for this is page cache writeback: dirty page cache is
+regulated through throttling buffered writers based on memory
+availability, and initiating batched write outs to the disk based on
+IO capacity.  Tracking and controlling writeback inside a cgroup thus
+requires the direct cooperation of the memory and the IO controller.
+
+This easily extends to other areas, such as CPU cycles consumed while
+performing memory reclaim or IO encryption.
+
+
+2-1. Contentious Restrictions
+
+For controllers of different resources to work together, they must
+agree on a common organization.  This uniform model across controllers
+imposes two contentious restrictions on the CPU controller: process
+granularity and the no-internal-process constraint.
+
+
+  2-1-1. Process Granularity
+
+  For memory, because an address space is shared between all threads
+  of a process, the terminal consumer is a process, not a thread.
+  Separating the threads of a single process into different memory
+  control domains doesn't make semantical sense.  cgroup v2 ensures
+  that all controller can agree on the same organization by requiring
+  that threads of the same process belong to the same cgroup.
+
+  There are other reasons to enforce process granularity.  One
+  important one is isolating system-level management operations from
+  in-process application operations.  The cgroup interface, being a
+  virtual filesystem, is very unfit for multiple independent
+  operations taking place at the same time as most operations have to
+  be multi-step and there is no way to synchronize multiple accessors.
+  See also [5] Documentation/cgroup-v2.txt, "R-2. Thread Granularity"
+
+
+  2-1-2. No Internal Process Constraint
+
+  cgroup v2 does not allow processes to belong to any cgroup which has
+  child cgroups when resource controllers are enabled on it (the
+  notable exception being the root cgroup itself).  This is because,
+  for some resources, a resource domain (cgroup) is not directly
+  comparable to the terminal consumer (process/task) of said resource,
+  and so putting the two into a sibling relationship isn't meaningful.
+
+  - Differing Control Parameters and Capabilities
+
+    A cgroup controller has different resource control parameters and
+    capabilities from a terminal consumer, be that a task or process.
+    There are a couple cases where a cgroup control knob can be mapped
+    to a per-task or per-process API but they are exceptions and the
+    mappings aren't obvious even in those cases.
+
+    For example, task priorities (also known as nice values) set
+    through setpriority(2) are mapped to the CPU controller
+    "cpu.shares" values.  However, how exactly the two ranges map and
+    even the fact that they map to each other at all are not obvious.
+
+    The situation gets further muddled when considering other resource
+    types and control knobs.  IO priorities set through ioprio_set(2)
+    cannot be mapped to IO controller weights and most cgroup resource
+    control knobs including the bandwidth control knobs of the CPU
+    controller don't have counterparts in the terminal consumers.
+
+  - Anonymous Resource Consumption
+
+    For CPU, every time slice consumed from inside a cgroup, which
+    comprises most but not all of consumed CPU time for the cgroup,
+    can be clearly attributed to a specific task or process.  Because
+    these two types of entities are directly comparable as consumers
+    of CPU time, it's theoretically possible to mix tasks and cgroups
+    on the same tree levels and let them directly compete for the time
+    quota available to their common ancestor.
+
+    However, the same can't be said for resource types like memory or
+    IO: the memory consumed by the page cache, for example, can be
+    tracked on a per-cgroup level, but due to mismatches in lifetimes
+    of involved objects (page cache can persist long after processes
+    are gone), shared usages and the implementation overhead of
+    tracking persistent state, it can no longer be attributed to
+    individual processes after instantiation.  Consequently, any IO
+    incurred by page cache writeback can be attributed to a cgroup,
+    but not to the individual consumers inside the cgroup.
+
+  For memory and IO, this makes a resource domain (cgroup) an object
+  of a fundamentally different type than a terminal consumer
+  (process).  A process can't be a first class object in the resource
+  distribution graph as its total resource consumption can't be
+  described without the containing resource domain.
+
+  Disallowing processes in internal cgroups avoids competition between
+  cgroups and processes which cannot be meaningfully defined for these
+  resources.  All resource control takes place among cgroups and a
+  terminal consumer interacts with the containing cgroup the same way
+  it would with the system without cgroup.
+
+  Root cgroup is exempt from this constraint, which is in line with
+  how root cgroup is handled in general - it's excluded from cgroup
+  resource accounting and control.
+
+
+Enforcing process granularity and no internal process constraint
+allows all controllers to be on the same footing in terms of resource
+distribution hierarchy.
+
+
+2-2. Impact on CPU Controller
+
+As indicated earlier, the CPU controller's resource distribution graph
+is the simplest.  Every schedulable resource consumption can be
+attributed to a specific task.  In addition, for weight based control,
+the per-task priority set through setpriority(2) can be translated to
+and from a per-cgroup weight.  As such, the CPU controller can treat a
+task and a cgroup symmetrically, allowing support for any tree layout
+of cgroups and tasks.  Both process granularity and the no internal
+process constraint restrict how the CPU controller can be used.
+
+
+  2-2-1. Impact of Process Granularity
+
+  Process granularity prevents tasks belonging to the same process to
+  be assigned to different cgroups.  It was pointed out [6] that this
+  excludes the valid use case of hierarchical CPU distribution within
+  processes.
+
+  To address this issue, the rgroup (resource group) [7][8][9]
+  interface, an extension of the existing setpriority(2) API, was
+  proposed, which is in line with other programmable priority
+  mechanisms and eliminates the risk of in-application configuration
+  and system configuration stepping on each other's toes.
+  Unfortunately, the proposal quickly turned into discussions around
+  cgroup v2 design decisions [4] and no consensus could be reached.
+
+
+  2-2-2. Impact of No Internal Process Constraint
+
+  The no internal process constraint disallows tasks from competing
+  directly against cgroups.  Here is an excerpt from Peter Zijlstra
+  pointing out the issue [10] - R, L and A are cgroups; t1, t2, t3 and
+  t4 are tasks:
+
+
+          R
+        / | \
+       t1 t2 A
+           /   \
+          t3   t4
+
+
+    Is fundamentally different from:
+
+
+               R
+             /   \
+           L       A
+         /   \   /   \
+        t1  t2  t3   t4
+
+
+    Because if in the first hierarchy you add a task (t5) to R, all of
+    its A will run at 1/4th of total bandwidth where before it had
+    1/3rd, whereas with the second example, if you add our t5 to L, A
+    doesn't get any less bandwidth.
+
+
+  It is true that the trees are semantically different from each other
+  and the symmetric handling of tasks and cgroups is aesthetically
+  pleasing.  However, it isn't clear what the practical usefulness of
+  a layout with direct competition between tasks and cgroups would be,
+  considering that number and behavior of tasks are controlled by each
+  application, and cgroups primarily deal with system level resource
+  distribution; changes in the number of active threads would directly
+  impact resource distribution.  Real world use cases of such layouts
+  could not be established during the discussions.
+
+
+2-3. Arguments for cgroup v2
+
+There are strong demands for comprehensive hierarchical resource
+control across all major resources, and establishing a common resource
+hierarchy is an essential step.  As with most engineering decisions,
+common resource hierarchy definition comes with its trade-offs.  With
+cgroup v2, the trade-offs are in the form of structural constraints
+which, among others, restrict the CPU controller's space of possible
+configurations.
+
+However, even with the restrictions, cgroup v2, in combination with
+rgroup, covers most of identified real world use cases while enabling
+new important use cases of resource control across multiple resource
+types that were fundamentally broken previously.
+
+Furthermore, for resource control, treating resource domains as
+objects of a different type from terminal consumers has important
+advantages - it can account for resource consumptions which are not
+tied to any specific terminal consumer, be that a task or process, and
+allows decoupling resource distribution controls from in-application
+APIs.  Even the CPU controller may benefit from it as the kernel can
+consume significant amount of CPU cycles in interrupt context or tasks
+shared across multiple resource domains (e.g. softirq).
+
+Finally, it's important to note that enabling cgroup v2 support for
+the CPU controller doesn't block use cases which require the features
+which are not available on cgroup v2.  Unlikely, but should anybody
+actually rely on the CPU controller's symmetric handling of tasks and
+cgroups, backward compatibility is and will be maintained by being
+able to disconnect the controller from the cgroup v2 hierarchy and use
+it standalone.  This also holds for cpuset which is often used in
+highly customized configurations which might be a poor fit for common
+resource domains.
+
+The required changes are minimal, the benefits for the target use
+cases are critical and obvious, and use cases which have to use v1 can
+continue to do so.
+
+
+3. Way Forward
+
+cgroup v2 primarily aims to solve the problem of comprehensive
+hierarchical resource control across all major computing resources,
+which is one of the core problems of modern server infrastructure
+engineering.  The trade-offs that cgroup v2 took are results of
+pursuing that goal and gaining a better understanding of the nature of
+resource control in the process.
+
+I believe that real world usages will prove cgroup v2's model right,
+considering the crucial pieces of comprehensive resource control that
+cannot be implemented without common resource domains.  This is not to
+say that cgroup v2 is fixed in stone and can't be updated; if there is
+an approach which better serves both comprehensive resource control
+and the CPU controller's flexibility, we will surely move towards
+that.  It goes without saying that discussions around such approach
+should consider practical aspects of resource control as a whole
+rather than absolutely focusing on a particular controller.
+
+Until such consensus can be reached, the CPU controller cgroup v2
+support will be maintained out of the mainline kernel in an easily
+accessible form.  If there is anything cgroup developers can do to
+ease the pain, please feel free to contact us on the cgroup mailing
+list at cgroups@vger.kernel.org.
+
+
+4. References
+
+[1]  http://lkml.kernel.org/r/20160105164834.GE5995@mtj.duckdns.org
+     [PATCH 1/2] sched: Misc preps for cgroup unified hierarchy interface
+     Tejun Heo <tj@kernel.org>
+
+[2]  http://lkml.kernel.org/r/20160105164852.GF5995@mtj.duckdns.org
+     [PATCH 2/2] sched: Implement interface for cgroup unified hierarchy
+     Tejun Heo <tj@kernel.org>
+
+[3]  http://lkml.kernel.org/r/1438641689-14655-4-git-send-email-tj@kernel.org
+     [PATCH 3/3] sched: Implement interface for cgroup unified hierarchy
+     Tejun Heo <tj@kernel.org>
+
+[4]  http://lkml.kernel.org/r/20160407064549.GH3430@twins.programming.kicks-ass.net
+     Re: [PATCHSET RFC cgroup/for-4.6] cgroup, sched: implement resource group and PRIO_RGRP
+     Peter Zijlstra <peterz@infradead.org>
+
+[5]  https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/cgroup-v2.txt
+     Control Group v2
+     Tejun Heo <tj@kernel.org>
+
+[6]  http://lkml.kernel.org/r/CAPM31RJNy3jgG=DYe6GO=wyL4BPPxwUm1f2S6YXacQmo7viFZA@mail.gmail.com
+     Re: [PATCH 3/3] sched: Implement interface for cgroup unified hierarchy
+     Paul Turner <pjt@google.com>
+
+[7]  http://lkml.kernel.org/r/20160105154503.GC5995@mtj.duckdns.org
+     [RFD] cgroup: thread granularity support for cpu controller
+     Tejun Heo <tj@kernel.org>
+
+[8]  http://lkml.kernel.org/r/1457710888-31182-1-git-send-email-tj@kernel.org
+     [PATCHSET RFC cgroup/for-4.6] cgroup, sched: implement resource group and PRIO_RGRP
+     Tejun Heo <tj@kernel.org>
+
+[9]  http://lkml.kernel.org/r/20160311160522.GA24046@htj.duckdns.org
+     Example program for PRIO_RGRP
+     Tejun Heo <tj@kernel.org>
+
+[10] http://lkml.kernel.org/r/20160407082810.GN3430@twins.programming.kicks-ass.net
+     Re: [PATCHSET RFC cgroup/for-4.6] cgroup, sched: implement resource
+     Peter Zijlstra <peterz@infradead.org>
--- a/pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/4.11.patch
+++ b/pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/4.11.patch
@ -0,0 +1,784 @@
+commit 827b86ad1dd21feed4c0b99faf6059f245f7dadb
+Author: Tejun Heo <tj@kernel.org>
+Date:   Fri Mar 11 07:31:23 2016 -0500
+
+    sched: Misc preps for cgroup unified hierarchy interface
+    
+    Make the following changes in preparation for the cpu controller
+    interface implementation for the unified hierarchy.  This patch
+    doesn't cause any functional differences.
+    
+    * s/cpu_stats_show()/cpu_cfs_stats_show()/
+    
+    * s/cpu_files/cpu_legacy_files/
+    
+    * Separate out cpuacct_stats_read() from cpuacct_stats_show().  While
+      at it, make the @val array u64 for consistency.
+    
+    Signed-off-by: Tejun Heo <tj@kernel.org>
+    Cc: Ingo Molnar <mingo@redhat.com>
+    Cc: Peter Zijlstra <peterz@infradead.org>
+    Cc: Li Zefan <lizefan@huawei.com>
+    Cc: Johannes Weiner <hannes@cmpxchg.org>
+
+diff --git a/kernel/sched/core.c b/kernel/sched/core.c
+index 3b31fc05a0f1..a1b95e83fa87 100644
+--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
+@@ -7174,7 +7174,7 @@ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
+ 	return ret;
+ }
+ 
+-static int cpu_stats_show(struct seq_file *sf, void *v)
+static int cpu_cfs_stats_show(struct seq_file *sf, void *v)
+ {
+ 	struct task_group *tg = css_tg(seq_css(sf));
+ 	struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+@@ -7214,7 +7214,7 @@ static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css,
+ }
+ #endif /* CONFIG_RT_GROUP_SCHED */
+ 
+-static struct cftype cpu_files[] = {
+static struct cftype cpu_legacy_files[] = {
+ #ifdef CONFIG_FAIR_GROUP_SCHED
+ 	{
+ 		.name = "shares",
+@@ -7235,7 +7235,7 @@ static struct cftype cpu_files[] = {
+ 	},
+ 	{
+ 		.name = "stat",
+-		.seq_show = cpu_stats_show,
+		.seq_show = cpu_cfs_stats_show,
+ 	},
+ #endif
+ #ifdef CONFIG_RT_GROUP_SCHED
+@@ -7261,7 +7261,7 @@ struct cgroup_subsys cpu_cgrp_subsys = {
+ 	.fork		= cpu_cgroup_fork,
+ 	.can_attach	= cpu_cgroup_can_attach,
+ 	.attach		= cpu_cgroup_attach,
+-	.legacy_cftypes	= cpu_files,
+	.legacy_cftypes	= cpu_legacy_files,
+ 	.early_init	= true,
+ };
+ 
+diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
+index f95ab29a45d0..6151c23f722f 100644
+--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
+@@ -276,26 +276,33 @@ static int cpuacct_all_seq_show(struct seq_file *m, void *V)
+ 	return 0;
+ }
+ 
+-static int cpuacct_stats_show(struct seq_file *sf, void *v)
+static void cpuacct_stats_read(struct cpuacct *ca,
+			       u64 (*val)[CPUACCT_STAT_NSTATS])
+ {
+-	struct cpuacct *ca = css_ca(seq_css(sf));
+-	s64 val[CPUACCT_STAT_NSTATS];
+ 	int cpu;
+-	int stat;
+ 
+-	memset(val, 0, sizeof(val));
+	memset(val, 0, sizeof(*val));
+
+ 	for_each_possible_cpu(cpu) {
+ 		u64 *cpustat = per_cpu_ptr(ca->cpustat, cpu)->cpustat;
+ 
+-		val[CPUACCT_STAT_USER]   += cpustat[CPUTIME_USER];
+-		val[CPUACCT_STAT_USER]   += cpustat[CPUTIME_NICE];
+-		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SYSTEM];
+-		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_IRQ];
+-		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SOFTIRQ];
+		(*val)[CPUACCT_STAT_USER]   += cpustat[CPUTIME_USER];
+		(*val)[CPUACCT_STAT_USER]   += cpustat[CPUTIME_NICE];
+		(*val)[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SYSTEM];
+		(*val)[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_IRQ];
+		(*val)[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SOFTIRQ];
+ 	}
+}
+
+static int cpuacct_stats_show(struct seq_file *sf, void *v)
+{
+	u64 val[CPUACCT_STAT_NSTATS];
+	int stat;
+
+	cpuacct_stats_read(css_ca(seq_css(sf)), &val);
+ 
+ 	for (stat = 0; stat < CPUACCT_STAT_NSTATS; stat++) {
+-		seq_printf(sf, "%s %lld\n",
+		seq_printf(sf, "%s %llu\n",
+ 			   cpuacct_stat_desc[stat],
+ 			   (long long)nsec_to_clock_t(val[stat]));
+ 	}
+
+commit fdb64d002b3a223ce4bb11aa4448a42050470052
+Author: Tejun Heo <tj@kernel.org>
+Date:   Fri Mar 11 07:31:23 2016 -0500
+
+    sched: Implement interface for cgroup unified hierarchy
+    
+    While the cpu controller doesn't have any functional problems, there
+    are a couple interface issues which can be addressed in the v2
+    interface.
+    
+    * cpuacct being a separate controller.  This separation is artificial
+      and rather pointless as demonstrated by most use cases co-mounting
+      the two controllers.  It also forces certain information to be
+      accounted twice.
+    
+    * Use of different time units.  Writable control knobs use
+      microseconds, some stat fields use nanoseconds while other cpuacct
+      stat fields use centiseconds.
+    
+    * Control knobs which can't be used in the root cgroup still show up
+      in the root.
+    
+    * Control knob names and semantics aren't consistent with other
+      controllers.
+    
+    This patchset implements cpu controller's interface on the unified
+    hierarchy which adheres to the controller file conventions described
+    in Documentation/cgroups/unified-hierarchy.txt.  Overall, the
+    following changes are made.
+    
+    * cpuacct is implictly enabled and disabled by cpu and its information
+      is reported through "cpu.stat" which now uses microseconds for all
+      time durations.  All time duration fields now have "_usec" appended
+      to them for clarity.  While this doesn't solve the double accounting
+      immediately, once majority of users switch to v2, cpu can directly
+      account and report the relevant stats and cpuacct can be disabled on
+      the unified hierarchy.
+    
+      Note that cpuacct.usage_percpu is currently not included in
+      "cpu.stat".  If this information is actually called for, it can be
+      added later.
+    
+    * "cpu.shares" is replaced with "cpu.weight" and operates on the
+      standard scale defined by CGROUP_WEIGHT_MIN/DFL/MAX (1, 100, 10000).
+      The weight is scaled to scheduler weight so that 100 maps to 1024
+      and the ratio relationship is preserved - if weight is W and its
+      scaled value is S, W / 100 == S / 1024.  While the mapped range is a
+      bit smaller than the orignal scheduler weight range, the dead zones
+      on both sides are relatively small and covers wider range than the
+      nice value mappings.  This file doesn't make sense in the root
+      cgroup and isn't create on root.
+    
+    * "cpu.cfs_quota_us" and "cpu.cfs_period_us" are replaced by "cpu.max"
+      which contains both quota and period.
+    
+    * "cpu.rt_runtime_us" and "cpu.rt_period_us" are replaced by
+      "cpu.rt.max" which contains both runtime and period.
+    
+    v2: cpu_stats_show() was incorrectly using CONFIG_FAIR_GROUP_SCHED for
+        CFS bandwidth stats and also using raw division for u64.  Use
+        CONFIG_CFS_BANDWITH and do_div() instead.
+    
+        The semantics of "cpu.rt.max" is not fully decided yet.  Dropped
+        for now.
+    
+    Signed-off-by: Tejun Heo <tj@kernel.org>
+    Cc: Ingo Molnar <mingo@redhat.com>
+    Cc: Peter Zijlstra <peterz@infradead.org>
+    Cc: Li Zefan <lizefan@huawei.com>
+    Cc: Johannes Weiner <hannes@cmpxchg.org>
+
+diff --git a/kernel/sched/core.c b/kernel/sched/core.c
+index a1b95e83fa87..f01d56e58a1b 100644
+--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
+@@ -7253,6 +7253,139 @@ static struct cftype cpu_legacy_files[] = {
+ 	{ }	/* Terminate */
+ };
+ 
+static int cpu_stats_show(struct seq_file *sf, void *v)
+{
+	cpuacct_cpu_stats_show(sf);
+
+#ifdef CONFIG_CFS_BANDWIDTH
+	{
+		struct task_group *tg = css_tg(seq_css(sf));
+		struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+		u64 throttled_usec;
+
+		throttled_usec = cfs_b->throttled_time;
+		do_div(throttled_usec, NSEC_PER_USEC);
+
+		seq_printf(sf, "nr_periods %d\n"
+			   "nr_throttled %d\n"
+			   "throttled_usec %llu\n",
+			   cfs_b->nr_periods, cfs_b->nr_throttled,
+			   throttled_usec);
+	}
+#endif
+	return 0;
+}
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static u64 cpu_weight_read_u64(struct cgroup_subsys_state *css,
+			       struct cftype *cft)
+{
+	struct task_group *tg = css_tg(css);
+	u64 weight = scale_load_down(tg->shares);
+
+	return DIV_ROUND_CLOSEST_ULL(weight * CGROUP_WEIGHT_DFL, 1024);
+}
+
+static int cpu_weight_write_u64(struct cgroup_subsys_state *css,
+				struct cftype *cftype, u64 weight)
+{
+	/*
+	 * cgroup weight knobs should use the common MIN, DFL and MAX
+	 * values which are 1, 100 and 10000 respectively.  While it loses
+	 * a bit of range on both ends, it maps pretty well onto the shares
+	 * value used by scheduler and the round-trip conversions preserve
+	 * the original value over the entire range.
+	 */
+	if (weight < CGROUP_WEIGHT_MIN || weight > CGROUP_WEIGHT_MAX)
+		return -ERANGE;
+
+	weight = DIV_ROUND_CLOSEST_ULL(weight * 1024, CGROUP_WEIGHT_DFL);
+
+	return sched_group_set_shares(css_tg(css), scale_load(weight));
+}
+#endif
+
+static void __maybe_unused cpu_period_quota_print(struct seq_file *sf,
+						  long period, long quota)
+{
+	if (quota < 0)
+		seq_puts(sf, "max");
+	else
+		seq_printf(sf, "%ld", quota);
+
+	seq_printf(sf, " %ld\n", period);
+}
+
+/* caller should put the current value in *@periodp before calling */
+static int __maybe_unused cpu_period_quota_parse(char *buf,
+						 u64 *periodp, u64 *quotap)
+{
+	char tok[21];	/* U64_MAX */
+
+	if (!sscanf(buf, "%s %llu", tok, periodp))
+		return -EINVAL;
+
+	*periodp *= NSEC_PER_USEC;
+
+	if (sscanf(tok, "%llu", quotap))
+		*quotap *= NSEC_PER_USEC;
+	else if (!strcmp(tok, "max"))
+		*quotap = RUNTIME_INF;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+#ifdef CONFIG_CFS_BANDWIDTH
+static int cpu_max_show(struct seq_file *sf, void *v)
+{
+	struct task_group *tg = css_tg(seq_css(sf));
+
+	cpu_period_quota_print(sf, tg_get_cfs_period(tg), tg_get_cfs_quota(tg));
+	return 0;
+}
+
+static ssize_t cpu_max_write(struct kernfs_open_file *of,
+			     char *buf, size_t nbytes, loff_t off)
+{
+	struct task_group *tg = css_tg(of_css(of));
+	u64 period = tg_get_cfs_period(tg);
+	u64 quota;
+	int ret;
+
+	ret = cpu_period_quota_parse(buf, &period, &quota);
+	if (!ret)
+		ret = tg_set_cfs_bandwidth(tg, period, quota);
+	return ret ?: nbytes;
+}
+#endif
+
+static struct cftype cpu_files[] = {
+	{
+		.name = "stat",
+		.flags = CFTYPE_NOT_ON_ROOT,
+		.seq_show = cpu_stats_show,
+	},
+#ifdef CONFIG_FAIR_GROUP_SCHED
+	{
+		.name = "weight",
+		.flags = CFTYPE_NOT_ON_ROOT,
+		.read_u64 = cpu_weight_read_u64,
+		.write_u64 = cpu_weight_write_u64,
+	},
+#endif
+#ifdef CONFIG_CFS_BANDWIDTH
+	{
+		.name = "max",
+		.flags = CFTYPE_NOT_ON_ROOT,
+		.seq_show = cpu_max_show,
+		.write = cpu_max_write,
+	},
+#endif
+	{ }	/* terminate */
+};
+
+ struct cgroup_subsys cpu_cgrp_subsys = {
+ 	.css_alloc	= cpu_cgroup_css_alloc,
+ 	.css_online	= cpu_cgroup_css_online,
+@@ -7262,7 +7395,15 @@ struct cgroup_subsys cpu_cgrp_subsys = {
+ 	.can_attach	= cpu_cgroup_can_attach,
+ 	.attach		= cpu_cgroup_attach,
+ 	.legacy_cftypes	= cpu_legacy_files,
+	.dfl_cftypes	= cpu_files,
+ 	.early_init	= true,
+#ifdef CONFIG_CGROUP_CPUACCT
+	/*
+	 * cpuacct is enabled together with cpu on the unified hierarchy
+	 * and its stats are reported through "cpu.stat".
+	 */
+	.depends_on	= 1 << cpuacct_cgrp_id,
+#endif
+ };
+ 
+ #endif	/* CONFIG_CGROUP_SCHED */
+diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
+index 6151c23f722f..fc1cf13c3af1 100644
+--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
+@@ -347,6 +347,31 @@ static struct cftype files[] = {
+ 	{ }	/* terminate */
+ };
+ 
+/* used to print cpuacct stats in cpu.stat on the unified hierarchy */
+void cpuacct_cpu_stats_show(struct seq_file *sf)
+{
+	struct cgroup_subsys_state *css;
+	u64 usage, val[CPUACCT_STAT_NSTATS];
+
+	css = cgroup_get_e_css(seq_css(sf)->cgroup, &cpuacct_cgrp_subsys);
+
+	usage = cpuusage_read(css, seq_cft(sf));
+	cpuacct_stats_read(css_ca(css), &val);
+
+	val[CPUACCT_STAT_USER] *= TICK_NSEC;
+	val[CPUACCT_STAT_SYSTEM] *= TICK_NSEC;
+	do_div(usage, NSEC_PER_USEC);
+	do_div(val[CPUACCT_STAT_USER], NSEC_PER_USEC);
+	do_div(val[CPUACCT_STAT_SYSTEM], NSEC_PER_USEC);
+
+	seq_printf(sf, "usage_usec %llu\n"
+		   "user_usec %llu\n"
+		   "system_usec %llu\n",
+		   usage, val[CPUACCT_STAT_USER], val[CPUACCT_STAT_SYSTEM]);
+
+	css_put(css);
+}
+
+ /*
+  * charge this task's execution time to its accounting group.
+  *
+diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h
+index ba72807c73d4..ddf7af466d35 100644
+--- a/kernel/sched/cpuacct.h
+++ b/kernel/sched/cpuacct.h
+@@ -2,6 +2,7 @@
+ 
+ extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
+ extern void cpuacct_account_field(struct task_struct *tsk, int index, u64 val);
+extern void cpuacct_cpu_stats_show(struct seq_file *sf);
+ 
+ #else
+ 
+@@ -14,4 +15,8 @@ cpuacct_account_field(struct task_struct *tsk, int index, u64 val)
+ {
+ }
+ 
+static inline void cpuacct_cpu_stats_show(struct seq_file *sf)
+{
+}
+
+ #endif
+
+commit 8dde150866b8c433216105c50b7e889d5242d583
+Author: Tejun Heo <tj@kernel.org>
+Date:   Fri Aug 5 12:41:01 2016 -0400
+
+    cgroup: add documentation regarding CPU controller cgroup v2 support
+    
+    Signed-off-by: Tejun Heo <tj@kernel.org>
+
+diff --git a/Documentation/cgroup-v2-cpu.txt b/Documentation/cgroup-v2-cpu.txt
+new file mode 100644
+index 000000000000..1ed7032d4472
+--- /dev/null
+++ b/Documentation/cgroup-v2-cpu.txt
+@@ -0,0 +1,368 @@
+
+
+CPU Controller on Control Group v2
+
+August, 2016		Tejun Heo <tj@kernel.org>
+
+
+While most controllers have support for cgroup v2 now, the CPU
+controller support is not upstream yet due to objections from the
+scheduler maintainers on the basic designs of cgroup v2.  This
+document explains the current situation as well as an interim
+solution, and details the disagreements and arguments.  The latest
+version of this document can be found at the following URL.
+
+ https://git.kernel.org/cgit/linux/kernel/git/tj/cgroup.git/tree/Documentation/cgroup-v2-cpu.txt?h=cgroup-v2-cpu
+
+This document was posted to the linux-kernel and cgroup mailing lists.
+Unfortunately, no consensus was reached as of Oct, 2016.  The thread
+can be found at the following URL.
+
+ http://lkml.kernel.org/r/20160805170752.GK2542@mtj.duckdns.org
+
+
+CONTENTS
+
+1. Current Situation and Interim Solution
+2. Disagreements and Arguments
+  2-1. Contentious Restrictions
+    2-1-1. Process Granularity
+    2-1-2. No Internal Process Constraint
+  2-2. Impact on CPU Controller
+    2-2-1. Impact of Process Granularity
+    2-2-2. Impact of No Internal Process Constraint
+  2-3. Arguments for cgroup v2
+3. Way Forward
+4. References
+
+
+1. Current Situation and Interim Solution
+
+All objections from the scheduler maintainers apply to cgroup v2 core
+design, and there are no known objections to the specifics of the CPU
+controller cgroup v2 interface.  The only blocked part is changes to
+expose the CPU controller interface on cgroup v2, which comprises the
+following two patches:
+
+ [1] sched: Misc preps for cgroup unified hierarchy interface
+ [2] sched: Implement interface for cgroup unified hierarchy
+
+The necessary changes are superficial and implement the interface
+files on cgroup v2.  The combined diffstat is as follows.
+
+ kernel/sched/core.c    |  149 +++++++++++++++++++++++++++++++++++++++++++++++--
+ kernel/sched/cpuacct.c |   57 ++++++++++++------
+ kernel/sched/cpuacct.h |    5 +
+ 3 files changed, 189 insertions(+), 22 deletions(-)
+
+The patches are easy to apply and forward-port.  The following git
+branch will always carry the two patches on top of the latest release
+of the upstream kernel.
+
+ git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git/cgroup-v2-cpu
+
+There also are versioned branches going back to v4.4.
+
+ git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git/cgroup-v2-cpu-$KERNEL_VER
+
+While it's difficult to tell whether the CPU controller support will
+be merged, there are crucial resource control features in cgroup v2
+that are only possible due to the design choices that are being
+objected to, and every effort will be made to ease enabling the CPU
+controller cgroup v2 support out-of-tree for parties which choose to.
+
+
+2. Disagreements and Arguments
+
+There have been several lengthy discussion threads [3][4] on LKML
+around the structural constraints of cgroup v2.  The two that affect
+the CPU controller are process granularity and no internal process
+constraint.  Both arise primarily from the need for common resource
+domain definition across different resources.
+
+The common resource domain is a powerful concept in cgroup v2 that
+allows controllers to make basic assumptions about the structural
+organization of processes and controllers inside the cgroup hierarchy,
+and thus solve problems spanning multiple types of resources.  The
+prime example for this is page cache writeback: dirty page cache is
+regulated through throttling buffered writers based on memory
+availability, and initiating batched write outs to the disk based on
+IO capacity.  Tracking and controlling writeback inside a cgroup thus
+requires the direct cooperation of the memory and the IO controller.
+
+This easily extends to other areas, such as CPU cycles consumed while
+performing memory reclaim or IO encryption.
+
+
+2-1. Contentious Restrictions
+
+For controllers of different resources to work together, they must
+agree on a common organization.  This uniform model across controllers
+imposes two contentious restrictions on the CPU controller: process
+granularity and the no-internal-process constraint.
+
+
+  2-1-1. Process Granularity
+
+  For memory, because an address space is shared between all threads
+  of a process, the terminal consumer is a process, not a thread.
+  Separating the threads of a single process into different memory
+  control domains doesn't make semantical sense.  cgroup v2 ensures
+  that all controller can agree on the same organization by requiring
+  that threads of the same process belong to the same cgroup.
+
+  There are other reasons to enforce process granularity.  One
+  important one is isolating system-level management operations from
+  in-process application operations.  The cgroup interface, being a
+  virtual filesystem, is very unfit for multiple independent
+  operations taking place at the same time as most operations have to
+  be multi-step and there is no way to synchronize multiple accessors.
+  See also [5] Documentation/cgroup-v2.txt, "R-2. Thread Granularity"
+
+
+  2-1-2. No Internal Process Constraint
+
+  cgroup v2 does not allow processes to belong to any cgroup which has
+  child cgroups when resource controllers are enabled on it (the
+  notable exception being the root cgroup itself).  This is because,
+  for some resources, a resource domain (cgroup) is not directly
+  comparable to the terminal consumer (process/task) of said resource,
+  and so putting the two into a sibling relationship isn't meaningful.
+
+  - Differing Control Parameters and Capabilities
+
+    A cgroup controller has different resource control parameters and
+    capabilities from a terminal consumer, be that a task or process.
+    There are a couple cases where a cgroup control knob can be mapped
+    to a per-task or per-process API but they are exceptions and the
+    mappings aren't obvious even in those cases.
+
+    For example, task priorities (also known as nice values) set
+    through setpriority(2) are mapped to the CPU controller
+    "cpu.shares" values.  However, how exactly the two ranges map and
+    even the fact that they map to each other at all are not obvious.
+
+    The situation gets further muddled when considering other resource
+    types and control knobs.  IO priorities set through ioprio_set(2)
+    cannot be mapped to IO controller weights and most cgroup resource
+    control knobs including the bandwidth control knobs of the CPU
+    controller don't have counterparts in the terminal consumers.
+
+  - Anonymous Resource Consumption
+
+    For CPU, every time slice consumed from inside a cgroup, which
+    comprises most but not all of consumed CPU time for the cgroup,
+    can be clearly attributed to a specific task or process.  Because
+    these two types of entities are directly comparable as consumers
+    of CPU time, it's theoretically possible to mix tasks and cgroups
+    on the same tree levels and let them directly compete for the time
+    quota available to their common ancestor.
+
+    However, the same can't be said for resource types like memory or
+    IO: the memory consumed by the page cache, for example, can be
+    tracked on a per-cgroup level, but due to mismatches in lifetimes
+    of involved objects (page cache can persist long after processes
+    are gone), shared usages and the implementation overhead of
+    tracking persistent state, it can no longer be attributed to
+    individual processes after instantiation.  Consequently, any IO
+    incurred by page cache writeback can be attributed to a cgroup,
+    but not to the individual consumers inside the cgroup.
+
+  For memory and IO, this makes a resource domain (cgroup) an object
+  of a fundamentally different type than a terminal consumer
+  (process).  A process can't be a first class object in the resource
+  distribution graph as its total resource consumption can't be
+  described without the containing resource domain.
+
+  Disallowing processes in internal cgroups avoids competition between
+  cgroups and processes which cannot be meaningfully defined for these
+  resources.  All resource control takes place among cgroups and a
+  terminal consumer interacts with the containing cgroup the same way
+  it would with the system without cgroup.
+
+  Root cgroup is exempt from this constraint, which is in line with
+  how root cgroup is handled in general - it's excluded from cgroup
+  resource accounting and control.
+
+
+Enforcing process granularity and no internal process constraint
+allows all controllers to be on the same footing in terms of resource
+distribution hierarchy.
+
+
+2-2. Impact on CPU Controller
+
+As indicated earlier, the CPU controller's resource distribution graph
+is the simplest.  Every schedulable resource consumption can be
+attributed to a specific task.  In addition, for weight based control,
+the per-task priority set through setpriority(2) can be translated to
+and from a per-cgroup weight.  As such, the CPU controller can treat a
+task and a cgroup symmetrically, allowing support for any tree layout
+of cgroups and tasks.  Both process granularity and the no internal
+process constraint restrict how the CPU controller can be used.
+
+
+  2-2-1. Impact of Process Granularity
+
+  Process granularity prevents tasks belonging to the same process to
+  be assigned to different cgroups.  It was pointed out [6] that this
+  excludes the valid use case of hierarchical CPU distribution within
+  processes.
+
+  To address this issue, the rgroup (resource group) [7][8][9]
+  interface, an extension of the existing setpriority(2) API, was
+  proposed, which is in line with other programmable priority
+  mechanisms and eliminates the risk of in-application configuration
+  and system configuration stepping on each other's toes.
+  Unfortunately, the proposal quickly turned into discussions around
+  cgroup v2 design decisions [4] and no consensus could be reached.
+
+
+  2-2-2. Impact of No Internal Process Constraint
+
+  The no internal process constraint disallows tasks from competing
+  directly against cgroups.  Here is an excerpt from Peter Zijlstra
+  pointing out the issue [10] - R, L and A are cgroups; t1, t2, t3 and
+  t4 are tasks:
+
+
+          R
+        / | \
+       t1 t2 A
+           /   \
+          t3   t4
+
+
+    Is fundamentally different from:
+
+
+               R
+             /   \
+           L       A
+         /   \   /   \
+        t1  t2  t3   t4
+
+
+    Because if in the first hierarchy you add a task (t5) to R, all of
+    its A will run at 1/4th of total bandwidth where before it had
+    1/3rd, whereas with the second example, if you add our t5 to L, A
+    doesn't get any less bandwidth.
+
+
+  It is true that the trees are semantically different from each other
+  and the symmetric handling of tasks and cgroups is aesthetically
+  pleasing.  However, it isn't clear what the practical usefulness of
+  a layout with direct competition between tasks and cgroups would be,
+  considering that number and behavior of tasks are controlled by each
+  application, and cgroups primarily deal with system level resource
+  distribution; changes in the number of active threads would directly
+  impact resource distribution.  Real world use cases of such layouts
+  could not be established during the discussions.
+
+
+2-3. Arguments for cgroup v2
+
+There are strong demands for comprehensive hierarchical resource
+control across all major resources, and establishing a common resource
+hierarchy is an essential step.  As with most engineering decisions,
+common resource hierarchy definition comes with its trade-offs.  With
+cgroup v2, the trade-offs are in the form of structural constraints
+which, among others, restrict the CPU controller's space of possible
+configurations.
+
+However, even with the restrictions, cgroup v2, in combination with
+rgroup, covers most of identified real world use cases while enabling
+new important use cases of resource control across multiple resource
+types that were fundamentally broken previously.
+
+Furthermore, for resource control, treating resource domains as
+objects of a different type from terminal consumers has important
+advantages - it can account for resource consumptions which are not
+tied to any specific terminal consumer, be that a task or process, and
+allows decoupling resource distribution controls from in-application
+APIs.  Even the CPU controller may benefit from it as the kernel can
+consume significant amount of CPU cycles in interrupt context or tasks
+shared across multiple resource domains (e.g. softirq).
+
+Finally, it's important to note that enabling cgroup v2 support for
+the CPU controller doesn't block use cases which require the features
+which are not available on cgroup v2.  Unlikely, but should anybody
+actually rely on the CPU controller's symmetric handling of tasks and
+cgroups, backward compatibility is and will be maintained by being
+able to disconnect the controller from the cgroup v2 hierarchy and use
+it standalone.  This also holds for cpuset which is often used in
+highly customized configurations which might be a poor fit for common
+resource domains.
+
+The required changes are minimal, the benefits for the target use
+cases are critical and obvious, and use cases which have to use v1 can
+continue to do so.
+
+
+3. Way Forward
+
+cgroup v2 primarily aims to solve the problem of comprehensive
+hierarchical resource control across all major computing resources,
+which is one of the core problems of modern server infrastructure
+engineering.  The trade-offs that cgroup v2 took are results of
+pursuing that goal and gaining a better understanding of the nature of
+resource control in the process.
+
+I believe that real world usages will prove cgroup v2's model right,
+considering the crucial pieces of comprehensive resource control that
+cannot be implemented without common resource domains.  This is not to
+say that cgroup v2 is fixed in stone and can't be updated; if there is
+an approach which better serves both comprehensive resource control
+and the CPU controller's flexibility, we will surely move towards
+that.  It goes without saying that discussions around such approach
+should consider practical aspects of resource control as a whole
+rather than absolutely focusing on a particular controller.
+
+Until such consensus can be reached, the CPU controller cgroup v2
+support will be maintained out of the mainline kernel in an easily
+accessible form.  If there is anything cgroup developers can do to
+ease the pain, please feel free to contact us on the cgroup mailing
+list at cgroups@vger.kernel.org.
+
+
+4. References
+
+[1]  http://lkml.kernel.org/r/20160105164834.GE5995@mtj.duckdns.org
+     [PATCH 1/2] sched: Misc preps for cgroup unified hierarchy interface
+     Tejun Heo <tj@kernel.org>
+
+[2]  http://lkml.kernel.org/r/20160105164852.GF5995@mtj.duckdns.org
+     [PATCH 2/2] sched: Implement interface for cgroup unified hierarchy
+     Tejun Heo <tj@kernel.org>
+
+[3]  http://lkml.kernel.org/r/1438641689-14655-4-git-send-email-tj@kernel.org
+     [PATCH 3/3] sched: Implement interface for cgroup unified hierarchy
+     Tejun Heo <tj@kernel.org>
+
+[4]  http://lkml.kernel.org/r/20160407064549.GH3430@twins.programming.kicks-ass.net
+     Re: [PATCHSET RFC cgroup/for-4.6] cgroup, sched: implement resource group and PRIO_RGRP
+     Peter Zijlstra <peterz@infradead.org>
+
+[5]  https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/cgroup-v2.txt
+     Control Group v2
+     Tejun Heo <tj@kernel.org>
+
+[6]  http://lkml.kernel.org/r/CAPM31RJNy3jgG=DYe6GO=wyL4BPPxwUm1f2S6YXacQmo7viFZA@mail.gmail.com
+     Re: [PATCH 3/3] sched: Implement interface for cgroup unified hierarchy
+     Paul Turner <pjt@google.com>
+
+[7]  http://lkml.kernel.org/r/20160105154503.GC5995@mtj.duckdns.org
+     [RFD] cgroup: thread granularity support for cpu controller
+     Tejun Heo <tj@kernel.org>
+
+[8]  http://lkml.kernel.org/r/1457710888-31182-1-git-send-email-tj@kernel.org
+     [PATCHSET RFC cgroup/for-4.6] cgroup, sched: implement resource group and PRIO_RGRP
+     Tejun Heo <tj@kernel.org>
+
+[9]  http://lkml.kernel.org/r/20160311160522.GA24046@htj.duckdns.org
+     Example program for PRIO_RGRP
+     Tejun Heo <tj@kernel.org>
+
+[10] http://lkml.kernel.org/r/20160407082810.GN3430@twins.programming.kicks-ass.net
+     Re: [PATCHSET RFC cgroup/for-4.6] cgroup, sched: implement resource
+     Peter Zijlstra <peterz@infradead.org>
--- a/pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/4.6.patch
+++ b/pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/4.6.patch
@ -1,407 +0,0 @@
-commit 6426c5b02d4aab620219b08a5d97ad8851b56b0d
-Author: Tejun Heo <tj@kernel.org>
-Date:   Fri Mar 11 07:31:23 2016 -0500
-
-    sched: Misc preps for cgroup unified hierarchy interface
-    
-    Make the following changes in preparation for the cpu controller
-    interface implementation for the unified hierarchy.  This patch
-    doesn't cause any functional differences.
-    
-    * s/cpu_stats_show()/cpu_cfs_stats_show()/
-    
-    * s/cpu_files/cpu_legacy_files/
-    
-    * Separate out cpuacct_stats_read() from cpuacct_stats_show().  While
-      at it, remove pointless cpuacct_stat_desc[] array.
-    
-    Signed-off-by: Tejun Heo <tj@kernel.org>
-    Cc: Ingo Molnar <mingo@redhat.com>
-    Cc: Peter Zijlstra <peterz@infradead.org>
-    Cc: Li Zefan <lizefan@huawei.com>
-    Cc: Johannes Weiner <hannes@cmpxchg.org>
-
-diff --git a/kernel/sched/core.c b/kernel/sched/core.c
-index d1f7149..0d34f35 100644
--- a/kernel/sched/core.c
-+++ b/kernel/sched/core.c
-@@ -8371,7 +8371,7 @@ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
- 	return ret;
- }
- 
-static int cpu_stats_show(struct seq_file *sf, void *v)
-+static int cpu_cfs_stats_show(struct seq_file *sf, void *v)
- {
- 	struct task_group *tg = css_tg(seq_css(sf));
- 	struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
-@@ -8411,7 +8411,7 @@ static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css,
- }
- #endif /* CONFIG_RT_GROUP_SCHED */
- 
-static struct cftype cpu_files[] = {
-+static struct cftype cpu_legacy_files[] = {
- #ifdef CONFIG_FAIR_GROUP_SCHED
- 	{
- 		.name = "shares",
-@@ -8432,7 +8432,7 @@ static struct cftype cpu_files[] = {
- 	},
- 	{
- 		.name = "stat",
-		.seq_show = cpu_stats_show,
-+		.seq_show = cpu_cfs_stats_show,
- 	},
- #endif
- #ifdef CONFIG_RT_GROUP_SCHED
-@@ -8457,7 +8457,7 @@ struct cgroup_subsys cpu_cgrp_subsys = {
- 	.fork		= cpu_cgroup_fork,
- 	.can_attach	= cpu_cgroup_can_attach,
- 	.attach		= cpu_cgroup_attach,
-	.legacy_cftypes	= cpu_files,
-+	.legacy_cftypes	= cpu_legacy_files,
- 	.early_init	= true,
- };
- 
-diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
-index 4a81120..b99030a 100644
--- a/kernel/sched/cpuacct.c
-+++ b/kernel/sched/cpuacct.c
-@@ -180,36 +180,33 @@ static int cpuacct_percpu_seq_show(struct seq_file *m, void *V)
- 	return 0;
- }
- 
-static const char * const cpuacct_stat_desc[] = {
-	[CPUACCT_STAT_USER] = "user",
-	[CPUACCT_STAT_SYSTEM] = "system",
-};
-
-static int cpuacct_stats_show(struct seq_file *sf, void *v)
-+static void cpuacct_stats_read(struct cpuacct *ca, u64 *userp, u64 *sysp)
- {
-	struct cpuacct *ca = css_ca(seq_css(sf));
- 	int cpu;
-	s64 val = 0;
- 
-+	*userp = 0;
- 	for_each_online_cpu(cpu) {
- 		struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
-		val += kcpustat->cpustat[CPUTIME_USER];
-		val += kcpustat->cpustat[CPUTIME_NICE];
-+		*userp += kcpustat->cpustat[CPUTIME_USER];
-+		*userp += kcpustat->cpustat[CPUTIME_NICE];
- 	}
-	val = cputime64_to_clock_t(val);
-	seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_USER], val);
- 
-	val = 0;
-+	*sysp = 0;
- 	for_each_online_cpu(cpu) {
- 		struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
-		val += kcpustat->cpustat[CPUTIME_SYSTEM];
-		val += kcpustat->cpustat[CPUTIME_IRQ];
-		val += kcpustat->cpustat[CPUTIME_SOFTIRQ];
-+		*sysp += kcpustat->cpustat[CPUTIME_SYSTEM];
-+		*sysp += kcpustat->cpustat[CPUTIME_IRQ];
-+		*sysp += kcpustat->cpustat[CPUTIME_SOFTIRQ];
- 	}
-+}
- 
-	val = cputime64_to_clock_t(val);
-	seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val);
-+static int cpuacct_stats_show(struct seq_file *sf, void *v)
-+{
-+	cputime64_t user, sys;
- 
-+	cpuacct_stats_read(css_ca(seq_css(sf)), &user, &sys);
-+	seq_printf(sf, "user %lld\n", cputime64_to_clock_t(user));
-+	seq_printf(sf, "system %lld\n", cputime64_to_clock_t(sys));
- 	return 0;
- }
- 
-
-commit d2a799f795a5d5a69c9dc365c34f926e0649f840
-Author: Tejun Heo <tj@kernel.org>
-Date:   Fri Mar 11 07:31:23 2016 -0500
-
-    sched: Implement interface for cgroup unified hierarchy
-    
-    While the cpu controller doesn't have any functional problems, there
-    are a couple interface issues which can be addressed in the v2
-    interface.
-    
-    * cpuacct being a separate controller.  This separation is artificial
-      and rather pointless as demonstrated by most use cases co-mounting
-      the two controllers.  It also forces certain information to be
-      accounted twice.
-    
-    * Use of different time units.  Writable control knobs use
-      microseconds, some stat fields use nanoseconds while other cpuacct
-      stat fields use centiseconds.
-    
-    * Control knobs which can't be used in the root cgroup still show up
-      in the root.
-    
-    * Control knob names and semantics aren't consistent with other
-      controllers.
-    
-    This patchset implements cpu controller's interface on the unified
-    hierarchy which adheres to the controller file conventions described
-    in Documentation/cgroups/unified-hierarchy.txt.  Overall, the
-    following changes are made.
-    
-    * cpuacct is implictly enabled and disabled by cpu and its information
-      is reported through "cpu.stat" which now uses microseconds for all
-      time durations.  All time duration fields now have "_usec" appended
-      to them for clarity.  While this doesn't solve the double accounting
-      immediately, once majority of users switch to v2, cpu can directly
-      account and report the relevant stats and cpuacct can be disabled on
-      the unified hierarchy.
-    
-      Note that cpuacct.usage_percpu is currently not included in
-      "cpu.stat".  If this information is actually called for, it can be
-      added later.
-    
-    * "cpu.shares" is replaced with "cpu.weight" and operates on the
-      standard scale defined by CGROUP_WEIGHT_MIN/DFL/MAX (1, 100, 10000).
-      The weight is scaled to scheduler weight so that 100 maps to 1024
-      and the ratio relationship is preserved - if weight is W and its
-      scaled value is S, W / 100 == S / 1024.  While the mapped range is a
-      bit smaller than the orignal scheduler weight range, the dead zones
-      on both sides are relatively small and covers wider range than the
-      nice value mappings.  This file doesn't make sense in the root
-      cgroup and isn't create on root.
-    
-    * "cpu.cfs_quota_us" and "cpu.cfs_period_us" are replaced by "cpu.max"
-      which contains both quota and period.
-    
-    * "cpu.rt_runtime_us" and "cpu.rt_period_us" are replaced by
-      "cpu.rt.max" which contains both runtime and period.
-    
-    v2: cpu_stats_show() was incorrectly using CONFIG_FAIR_GROUP_SCHED for
-        CFS bandwidth stats and also using raw division for u64.  Use
-        CONFIG_CFS_BANDWITH and do_div() instead.
-    
-        The semantics of "cpu.rt.max" is not fully decided yet.  Dropped
-        for now.
-    
-    Signed-off-by: Tejun Heo <tj@kernel.org>
-    Cc: Ingo Molnar <mingo@redhat.com>
-    Cc: Peter Zijlstra <peterz@infradead.org>
-    Cc: Li Zefan <lizefan@huawei.com>
-    Cc: Johannes Weiner <hannes@cmpxchg.org>
-
-diff --git a/kernel/sched/core.c b/kernel/sched/core.c
-index 0d34f35..5990efc 100644
--- a/kernel/sched/core.c
-+++ b/kernel/sched/core.c
-@@ -8450,6 +8450,139 @@ static struct cftype cpu_legacy_files[] = {
- 	{ }	/* terminate */
- };
- 
-+static int cpu_stats_show(struct seq_file *sf, void *v)
-+{
-+	cpuacct_cpu_stats_show(sf);
-+
-+#ifdef CONFIG_CFS_BANDWIDTH
-+	{
-+		struct task_group *tg = css_tg(seq_css(sf));
-+		struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
-+		u64 throttled_usec;
-+
-+		throttled_usec = cfs_b->throttled_time;
-+		do_div(throttled_usec, NSEC_PER_USEC);
-+
-+		seq_printf(sf, "nr_periods %d\n"
-+			   "nr_throttled %d\n"
-+			   "throttled_usec %llu\n",
-+			   cfs_b->nr_periods, cfs_b->nr_throttled,
-+			   throttled_usec);
-+	}
-+#endif
-+	return 0;
-+}
-+
-+#ifdef CONFIG_FAIR_GROUP_SCHED
-+static u64 cpu_weight_read_u64(struct cgroup_subsys_state *css,
-+			       struct cftype *cft)
-+{
-+	struct task_group *tg = css_tg(css);
-+	u64 weight = scale_load_down(tg->shares);
-+
-+	return DIV_ROUND_CLOSEST_ULL(weight * CGROUP_WEIGHT_DFL, 1024);
-+}
-+
-+static int cpu_weight_write_u64(struct cgroup_subsys_state *css,
-+				struct cftype *cftype, u64 weight)
-+{
-+	/*
-+	 * cgroup weight knobs should use the common MIN, DFL and MAX
-+	 * values which are 1, 100 and 10000 respectively.  While it loses
-+	 * a bit of range on both ends, it maps pretty well onto the shares
-+	 * value used by scheduler and the round-trip conversions preserve
-+	 * the original value over the entire range.
-+	 */
-+	if (weight < CGROUP_WEIGHT_MIN || weight > CGROUP_WEIGHT_MAX)
-+		return -ERANGE;
-+
-+	weight = DIV_ROUND_CLOSEST_ULL(weight * 1024, CGROUP_WEIGHT_DFL);
-+
-+	return sched_group_set_shares(css_tg(css), scale_load(weight));
-+}
-+#endif
-+
-+static void __maybe_unused cpu_period_quota_print(struct seq_file *sf,
-+						  long period, long quota)
-+{
-+	if (quota < 0)
-+		seq_puts(sf, "max");
-+	else
-+		seq_printf(sf, "%ld", quota);
-+
-+	seq_printf(sf, " %ld\n", period);
-+}
-+
-+/* caller should put the current value in *@periodp before calling */
-+static int __maybe_unused cpu_period_quota_parse(char *buf,
-+						 u64 *periodp, u64 *quotap)
-+{
-+	char tok[21];	/* U64_MAX */
-+
-+	if (!sscanf(buf, "%s %llu", tok, periodp))
-+		return -EINVAL;
-+
-+	*periodp *= NSEC_PER_USEC;
-+
-+	if (sscanf(tok, "%llu", quotap))
-+		*quotap *= NSEC_PER_USEC;
-+	else if (!strcmp(tok, "max"))
-+		*quotap = RUNTIME_INF;
-+	else
-+		return -EINVAL;
-+
-+	return 0;
-+}
-+
-+#ifdef CONFIG_CFS_BANDWIDTH
-+static int cpu_max_show(struct seq_file *sf, void *v)
-+{
-+	struct task_group *tg = css_tg(seq_css(sf));
-+
-+	cpu_period_quota_print(sf, tg_get_cfs_period(tg), tg_get_cfs_quota(tg));
-+	return 0;
-+}
-+
-+static ssize_t cpu_max_write(struct kernfs_open_file *of,
-+			     char *buf, size_t nbytes, loff_t off)
-+{
-+	struct task_group *tg = css_tg(of_css(of));
-+	u64 period = tg_get_cfs_period(tg);
-+	u64 quota;
-+	int ret;
-+
-+	ret = cpu_period_quota_parse(buf, &period, &quota);
-+	if (!ret)
-+		ret = tg_set_cfs_bandwidth(tg, period, quota);
-+	return ret ?: nbytes;
-+}
-+#endif
-+
-+static struct cftype cpu_files[] = {
-+	{
-+		.name = "stat",
-+		.flags = CFTYPE_NOT_ON_ROOT,
-+		.seq_show = cpu_stats_show,
-+	},
-+#ifdef CONFIG_FAIR_GROUP_SCHED
-+	{
-+		.name = "weight",
-+		.flags = CFTYPE_NOT_ON_ROOT,
-+		.read_u64 = cpu_weight_read_u64,
-+		.write_u64 = cpu_weight_write_u64,
-+	},
-+#endif
-+#ifdef CONFIG_CFS_BANDWIDTH
-+	{
-+		.name = "max",
-+		.flags = CFTYPE_NOT_ON_ROOT,
-+		.seq_show = cpu_max_show,
-+		.write = cpu_max_write,
-+	},
-+#endif
-+	{ }	/* terminate */
-+};
-+
- struct cgroup_subsys cpu_cgrp_subsys = {
- 	.css_alloc	= cpu_cgroup_css_alloc,
- 	.css_released	= cpu_cgroup_css_released,
-@@ -8458,7 +8591,15 @@ struct cgroup_subsys cpu_cgrp_subsys = {
- 	.can_attach	= cpu_cgroup_can_attach,
- 	.attach		= cpu_cgroup_attach,
- 	.legacy_cftypes	= cpu_legacy_files,
-+	.dfl_cftypes	= cpu_files,
- 	.early_init	= true,
-+#ifdef CONFIG_CGROUP_CPUACCT
-+	/*
-+	 * cpuacct is enabled together with cpu on the unified hierarchy
-+	 * and its stats are reported through "cpu.stat".
-+	 */
-+	.depends_on	= 1 << cpuacct_cgrp_id,
-+#endif
- };
- 
- #endif	/* CONFIG_CGROUP_SCHED */
-diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
-index b99030a..a1a5a4b 100644
--- a/kernel/sched/cpuacct.c
-+++ b/kernel/sched/cpuacct.c
-@@ -227,6 +227,30 @@ static struct cftype files[] = {
- 	{ }	/* terminate */
- };
- 
-+/* used to print cpuacct stats in cpu.stat on the unified hierarchy */
-+void cpuacct_cpu_stats_show(struct seq_file *sf)
-+{
-+	struct cgroup_subsys_state *css;
-+	u64 usage, user, sys;
-+
-+	css = cgroup_get_e_css(seq_css(sf)->cgroup, &cpuacct_cgrp_subsys);
-+
-+	usage = cpuusage_read(css, seq_cft(sf));
-+	cpuacct_stats_read(css_ca(css), &user, &sys);
-+
-+	user *= TICK_NSEC;
-+	sys *= TICK_NSEC;
-+	do_div(usage, NSEC_PER_USEC);
-+	do_div(user, NSEC_PER_USEC);
-+	do_div(sys, NSEC_PER_USEC);
-+
-+	seq_printf(sf, "usage_usec %llu\n"
-+		   "user_usec %llu\n"
-+		   "system_usec %llu\n", usage, user, sys);
-+
-+	css_put(css);
-+}
-+
- /*
-  * charge this task's execution time to its accounting group.
-  *
-diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h
-index ba72807..ddf7af4 100644
--- a/kernel/sched/cpuacct.h
-+++ b/kernel/sched/cpuacct.h
-@@ -2,6 +2,7 @@
- 
- extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
- extern void cpuacct_account_field(struct task_struct *tsk, int index, u64 val);
-+extern void cpuacct_cpu_stats_show(struct seq_file *sf);
- 
- #else
- 
-@@ -14,4 +15,8 @@ cpuacct_account_field(struct task_struct *tsk, int index, u64 val)
- {
- }
- 
-+static inline void cpuacct_cpu_stats_show(struct seq_file *sf)
-+{
-+}
-+
- #endif
--- a/pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/4.7.patch
+++ b/pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/4.7.patch
@ -1,407 +0,0 @@
-commit 0d966df508ef4d6c0b1baae9e369f4fb0d3e10af
-Author: Tejun Heo <tj@kernel.org>
-Date:   Fri Mar 11 07:31:23 2016 -0500
-
-    sched: Misc preps for cgroup unified hierarchy interface
-    
-    Make the following changes in preparation for the cpu controller
-    interface implementation for the unified hierarchy.  This patch
-    doesn't cause any functional differences.
-    
-    * s/cpu_stats_show()/cpu_cfs_stats_show()/
-    
-    * s/cpu_files/cpu_legacy_files/
-    
-    * Separate out cpuacct_stats_read() from cpuacct_stats_show().  While
-      at it, remove pointless cpuacct_stat_desc[] array.
-    
-    Signed-off-by: Tejun Heo <tj@kernel.org>
-    Cc: Ingo Molnar <mingo@redhat.com>
-    Cc: Peter Zijlstra <peterz@infradead.org>
-    Cc: Li Zefan <lizefan@huawei.com>
-    Cc: Johannes Weiner <hannes@cmpxchg.org>
-
-diff --git a/kernel/sched/core.c b/kernel/sched/core.c
-index 97ee9ac..c148dfe 100644
--- a/kernel/sched/core.c
-+++ b/kernel/sched/core.c
-@@ -8482,7 +8482,7 @@ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
- 	return ret;
- }
- 
-static int cpu_stats_show(struct seq_file *sf, void *v)
-+static int cpu_cfs_stats_show(struct seq_file *sf, void *v)
- {
- 	struct task_group *tg = css_tg(seq_css(sf));
- 	struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
-@@ -8522,7 +8522,7 @@ static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css,
- }
- #endif /* CONFIG_RT_GROUP_SCHED */
- 
-static struct cftype cpu_files[] = {
-+static struct cftype cpu_legacy_files[] = {
- #ifdef CONFIG_FAIR_GROUP_SCHED
- 	{
- 		.name = "shares",
-@@ -8543,7 +8543,7 @@ static struct cftype cpu_files[] = {
- 	},
- 	{
- 		.name = "stat",
-		.seq_show = cpu_stats_show,
-+		.seq_show = cpu_cfs_stats_show,
- 	},
- #endif
- #ifdef CONFIG_RT_GROUP_SCHED
-@@ -8568,7 +8568,7 @@ struct cgroup_subsys cpu_cgrp_subsys = {
- 	.fork		= cpu_cgroup_fork,
- 	.can_attach	= cpu_cgroup_can_attach,
- 	.attach		= cpu_cgroup_attach,
-	.legacy_cftypes	= cpu_files,
-+	.legacy_cftypes	= cpu_legacy_files,
- 	.early_init	= true,
- };
- 
-diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
-index 41f85c4..3eb9eda 100644
--- a/kernel/sched/cpuacct.c
-+++ b/kernel/sched/cpuacct.c
-@@ -242,36 +242,33 @@ static int cpuacct_percpu_seq_show(struct seq_file *m, void *V)
- 	return __cpuacct_percpu_seq_show(m, CPUACCT_USAGE_NRUSAGE);
- }
- 
-static const char * const cpuacct_stat_desc[] = {
-	[CPUACCT_STAT_USER] = "user",
-	[CPUACCT_STAT_SYSTEM] = "system",
-};
-
-static int cpuacct_stats_show(struct seq_file *sf, void *v)
-+static void cpuacct_stats_read(struct cpuacct *ca, u64 *userp, u64 *sysp)
- {
-	struct cpuacct *ca = css_ca(seq_css(sf));
- 	int cpu;
-	s64 val = 0;
- 
-+	*userp = 0;
- 	for_each_possible_cpu(cpu) {
- 		struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
-		val += kcpustat->cpustat[CPUTIME_USER];
-		val += kcpustat->cpustat[CPUTIME_NICE];
-+		*userp += kcpustat->cpustat[CPUTIME_USER];
-+		*userp += kcpustat->cpustat[CPUTIME_NICE];
- 	}
-	val = cputime64_to_clock_t(val);
-	seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_USER], val);
- 
-	val = 0;
-+	*sysp = 0;
- 	for_each_possible_cpu(cpu) {
- 		struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
-		val += kcpustat->cpustat[CPUTIME_SYSTEM];
-		val += kcpustat->cpustat[CPUTIME_IRQ];
-		val += kcpustat->cpustat[CPUTIME_SOFTIRQ];
-+		*sysp += kcpustat->cpustat[CPUTIME_SYSTEM];
-+		*sysp += kcpustat->cpustat[CPUTIME_IRQ];
-+		*sysp += kcpustat->cpustat[CPUTIME_SOFTIRQ];
- 	}
-+}
- 
-	val = cputime64_to_clock_t(val);
-	seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val);
-+static int cpuacct_stats_show(struct seq_file *sf, void *v)
-+{
-+	cputime64_t user, sys;
- 
-+	cpuacct_stats_read(css_ca(seq_css(sf)), &user, &sys);
-+	seq_printf(sf, "user %lld\n", cputime64_to_clock_t(user));
-+	seq_printf(sf, "system %lld\n", cputime64_to_clock_t(sys));
- 	return 0;
- }
- 
-
-commit ed6d93036ec930cb774da10b7c87f67905ce71f1
-Author: Tejun Heo <tj@kernel.org>
-Date:   Fri Mar 11 07:31:23 2016 -0500
-
-    sched: Implement interface for cgroup unified hierarchy
-    
-    While the cpu controller doesn't have any functional problems, there
-    are a couple interface issues which can be addressed in the v2
-    interface.
-    
-    * cpuacct being a separate controller.  This separation is artificial
-      and rather pointless as demonstrated by most use cases co-mounting
-      the two controllers.  It also forces certain information to be
-      accounted twice.
-    
-    * Use of different time units.  Writable control knobs use
-      microseconds, some stat fields use nanoseconds while other cpuacct
-      stat fields use centiseconds.
-    
-    * Control knobs which can't be used in the root cgroup still show up
-      in the root.
-    
-    * Control knob names and semantics aren't consistent with other
-      controllers.
-    
-    This patchset implements cpu controller's interface on the unified
-    hierarchy which adheres to the controller file conventions described
-    in Documentation/cgroups/unified-hierarchy.txt.  Overall, the
-    following changes are made.
-    
-    * cpuacct is implictly enabled and disabled by cpu and its information
-      is reported through "cpu.stat" which now uses microseconds for all
-      time durations.  All time duration fields now have "_usec" appended
-      to them for clarity.  While this doesn't solve the double accounting
-      immediately, once majority of users switch to v2, cpu can directly
-      account and report the relevant stats and cpuacct can be disabled on
-      the unified hierarchy.
-    
-      Note that cpuacct.usage_percpu is currently not included in
-      "cpu.stat".  If this information is actually called for, it can be
-      added later.
-    
-    * "cpu.shares" is replaced with "cpu.weight" and operates on the
-      standard scale defined by CGROUP_WEIGHT_MIN/DFL/MAX (1, 100, 10000).
-      The weight is scaled to scheduler weight so that 100 maps to 1024
-      and the ratio relationship is preserved - if weight is W and its
-      scaled value is S, W / 100 == S / 1024.  While the mapped range is a
-      bit smaller than the orignal scheduler weight range, the dead zones
-      on both sides are relatively small and covers wider range than the
-      nice value mappings.  This file doesn't make sense in the root
-      cgroup and isn't create on root.
-    
-    * "cpu.cfs_quota_us" and "cpu.cfs_period_us" are replaced by "cpu.max"
-      which contains both quota and period.
-    
-    * "cpu.rt_runtime_us" and "cpu.rt_period_us" are replaced by
-      "cpu.rt.max" which contains both runtime and period.
-    
-    v2: cpu_stats_show() was incorrectly using CONFIG_FAIR_GROUP_SCHED for
-        CFS bandwidth stats and also using raw division for u64.  Use
-        CONFIG_CFS_BANDWITH and do_div() instead.
-    
-        The semantics of "cpu.rt.max" is not fully decided yet.  Dropped
-        for now.
-    
-    Signed-off-by: Tejun Heo <tj@kernel.org>
-    Cc: Ingo Molnar <mingo@redhat.com>
-    Cc: Peter Zijlstra <peterz@infradead.org>
-    Cc: Li Zefan <lizefan@huawei.com>
-    Cc: Johannes Weiner <hannes@cmpxchg.org>
-
-diff --git a/kernel/sched/core.c b/kernel/sched/core.c
-index c148dfe..7bba2c5 100644
--- a/kernel/sched/core.c
-+++ b/kernel/sched/core.c
-@@ -8561,6 +8561,139 @@ static struct cftype cpu_legacy_files[] = {
- 	{ }	/* terminate */
- };
- 
-+static int cpu_stats_show(struct seq_file *sf, void *v)
-+{
-+	cpuacct_cpu_stats_show(sf);
-+
-+#ifdef CONFIG_CFS_BANDWIDTH
-+	{
-+		struct task_group *tg = css_tg(seq_css(sf));
-+		struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
-+		u64 throttled_usec;
-+
-+		throttled_usec = cfs_b->throttled_time;
-+		do_div(throttled_usec, NSEC_PER_USEC);
-+
-+		seq_printf(sf, "nr_periods %d\n"
-+			   "nr_throttled %d\n"
-+			   "throttled_usec %llu\n",
-+			   cfs_b->nr_periods, cfs_b->nr_throttled,
-+			   throttled_usec);
-+	}
-+#endif
-+	return 0;
-+}
-+
-+#ifdef CONFIG_FAIR_GROUP_SCHED
-+static u64 cpu_weight_read_u64(struct cgroup_subsys_state *css,
-+			       struct cftype *cft)
-+{
-+	struct task_group *tg = css_tg(css);
-+	u64 weight = scale_load_down(tg->shares);
-+
-+	return DIV_ROUND_CLOSEST_ULL(weight * CGROUP_WEIGHT_DFL, 1024);
-+}
-+
-+static int cpu_weight_write_u64(struct cgroup_subsys_state *css,
-+				struct cftype *cftype, u64 weight)
-+{
-+	/*
-+	 * cgroup weight knobs should use the common MIN, DFL and MAX
-+	 * values which are 1, 100 and 10000 respectively.  While it loses
-+	 * a bit of range on both ends, it maps pretty well onto the shares
-+	 * value used by scheduler and the round-trip conversions preserve
-+	 * the original value over the entire range.
-+	 */
-+	if (weight < CGROUP_WEIGHT_MIN || weight > CGROUP_WEIGHT_MAX)
-+		return -ERANGE;
-+
-+	weight = DIV_ROUND_CLOSEST_ULL(weight * 1024, CGROUP_WEIGHT_DFL);
-+
-+	return sched_group_set_shares(css_tg(css), scale_load(weight));
-+}
-+#endif
-+
-+static void __maybe_unused cpu_period_quota_print(struct seq_file *sf,
-+						  long period, long quota)
-+{
-+	if (quota < 0)
-+		seq_puts(sf, "max");
-+	else
-+		seq_printf(sf, "%ld", quota);
-+
-+	seq_printf(sf, " %ld\n", period);
-+}
-+
-+/* caller should put the current value in *@periodp before calling */
-+static int __maybe_unused cpu_period_quota_parse(char *buf,
-+						 u64 *periodp, u64 *quotap)
-+{
-+	char tok[21];	/* U64_MAX */
-+
-+	if (!sscanf(buf, "%s %llu", tok, periodp))
-+		return -EINVAL;
-+
-+	*periodp *= NSEC_PER_USEC;
-+
-+	if (sscanf(tok, "%llu", quotap))
-+		*quotap *= NSEC_PER_USEC;
-+	else if (!strcmp(tok, "max"))
-+		*quotap = RUNTIME_INF;
-+	else
-+		return -EINVAL;
-+
-+	return 0;
-+}
-+
-+#ifdef CONFIG_CFS_BANDWIDTH
-+static int cpu_max_show(struct seq_file *sf, void *v)
-+{
-+	struct task_group *tg = css_tg(seq_css(sf));
-+
-+	cpu_period_quota_print(sf, tg_get_cfs_period(tg), tg_get_cfs_quota(tg));
-+	return 0;
-+}
-+
-+static ssize_t cpu_max_write(struct kernfs_open_file *of,
-+			     char *buf, size_t nbytes, loff_t off)
-+{
-+	struct task_group *tg = css_tg(of_css(of));
-+	u64 period = tg_get_cfs_period(tg);
-+	u64 quota;
-+	int ret;
-+
-+	ret = cpu_period_quota_parse(buf, &period, &quota);
-+	if (!ret)
-+		ret = tg_set_cfs_bandwidth(tg, period, quota);
-+	return ret ?: nbytes;
-+}
-+#endif
-+
-+static struct cftype cpu_files[] = {
-+	{
-+		.name = "stat",
-+		.flags = CFTYPE_NOT_ON_ROOT,
-+		.seq_show = cpu_stats_show,
-+	},
-+#ifdef CONFIG_FAIR_GROUP_SCHED
-+	{
-+		.name = "weight",
-+		.flags = CFTYPE_NOT_ON_ROOT,
-+		.read_u64 = cpu_weight_read_u64,
-+		.write_u64 = cpu_weight_write_u64,
-+	},
-+#endif
-+#ifdef CONFIG_CFS_BANDWIDTH
-+	{
-+		.name = "max",
-+		.flags = CFTYPE_NOT_ON_ROOT,
-+		.seq_show = cpu_max_show,
-+		.write = cpu_max_write,
-+	},
-+#endif
-+	{ }	/* terminate */
-+};
-+
- struct cgroup_subsys cpu_cgrp_subsys = {
- 	.css_alloc	= cpu_cgroup_css_alloc,
- 	.css_released	= cpu_cgroup_css_released,
-@@ -8569,7 +8702,15 @@ struct cgroup_subsys cpu_cgrp_subsys = {
- 	.can_attach	= cpu_cgroup_can_attach,
- 	.attach		= cpu_cgroup_attach,
- 	.legacy_cftypes	= cpu_legacy_files,
-+	.dfl_cftypes	= cpu_files,
- 	.early_init	= true,
-+#ifdef CONFIG_CGROUP_CPUACCT
-+	/*
-+	 * cpuacct is enabled together with cpu on the unified hierarchy
-+	 * and its stats are reported through "cpu.stat".
-+	 */
-+	.depends_on	= 1 << cpuacct_cgrp_id,
-+#endif
- };
- 
- #endif	/* CONFIG_CGROUP_SCHED */
-diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
-index 3eb9eda..7a02d26 100644
--- a/kernel/sched/cpuacct.c
-+++ b/kernel/sched/cpuacct.c
-@@ -305,6 +305,30 @@ static struct cftype files[] = {
- 	{ }	/* terminate */
- };
- 
-+/* used to print cpuacct stats in cpu.stat on the unified hierarchy */
-+void cpuacct_cpu_stats_show(struct seq_file *sf)
-+{
-+	struct cgroup_subsys_state *css;
-+	u64 usage, user, sys;
-+
-+	css = cgroup_get_e_css(seq_css(sf)->cgroup, &cpuacct_cgrp_subsys);
-+
-+	usage = cpuusage_read(css, seq_cft(sf));
-+	cpuacct_stats_read(css_ca(css), &user, &sys);
-+
-+	user *= TICK_NSEC;
-+	sys *= TICK_NSEC;
-+	do_div(usage, NSEC_PER_USEC);
-+	do_div(user, NSEC_PER_USEC);
-+	do_div(sys, NSEC_PER_USEC);
-+
-+	seq_printf(sf, "usage_usec %llu\n"
-+		   "user_usec %llu\n"
-+		   "system_usec %llu\n", usage, user, sys);
-+
-+	css_put(css);
-+}
-+
- /*
-  * charge this task's execution time to its accounting group.
-  *
-diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h
-index ba72807..ddf7af4 100644
--- a/kernel/sched/cpuacct.h
-+++ b/kernel/sched/cpuacct.h
-@@ -2,6 +2,7 @@
- 
- extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
- extern void cpuacct_account_field(struct task_struct *tsk, int index, u64 val);
-+extern void cpuacct_cpu_stats_show(struct seq_file *sf);
- 
- #else
- 
-@@ -14,4 +15,8 @@ cpuacct_account_field(struct task_struct *tsk, int index, u64 val)
- {
- }
- 
-+static inline void cpuacct_cpu_stats_show(struct seq_file *sf)
-+{
-+}
-+
- #endif
--- a/pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/4.9.patch
+++ b/pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/4.9.patch
@ -0,0 +1,784 @@
+commit 280858b0bb3384b9ec06b455e196b453888bd6b8
+Author: Tejun Heo <tj@kernel.org>
+Date:   Fri Mar 11 07:31:23 2016 -0500
+
+    sched: Misc preps for cgroup unified hierarchy interface
+    
+    Make the following changes in preparation for the cpu controller
+    interface implementation for the unified hierarchy.  This patch
+    doesn't cause any functional differences.
+    
+    * s/cpu_stats_show()/cpu_cfs_stats_show()/
+    
+    * s/cpu_files/cpu_legacy_files/
+    
+    * Separate out cpuacct_stats_read() from cpuacct_stats_show().  While
+      at it, make the @val array u64 for consistency.
+    
+    Signed-off-by: Tejun Heo <tj@kernel.org>
+    Cc: Ingo Molnar <mingo@redhat.com>
+    Cc: Peter Zijlstra <peterz@infradead.org>
+    Cc: Li Zefan <lizefan@huawei.com>
+    Cc: Johannes Weiner <hannes@cmpxchg.org>
+
+diff --git a/kernel/sched/core.c b/kernel/sched/core.c
+index 154fd689fe02..57472485b79c 100644
+--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
+@@ -8705,7 +8705,7 @@ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
+ 	return ret;
+ }
+ 
+-static int cpu_stats_show(struct seq_file *sf, void *v)
+static int cpu_cfs_stats_show(struct seq_file *sf, void *v)
+ {
+ 	struct task_group *tg = css_tg(seq_css(sf));
+ 	struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+@@ -8745,7 +8745,7 @@ static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css,
+ }
+ #endif /* CONFIG_RT_GROUP_SCHED */
+ 
+-static struct cftype cpu_files[] = {
+static struct cftype cpu_legacy_files[] = {
+ #ifdef CONFIG_FAIR_GROUP_SCHED
+ 	{
+ 		.name = "shares",
+@@ -8766,7 +8766,7 @@ static struct cftype cpu_files[] = {
+ 	},
+ 	{
+ 		.name = "stat",
+-		.seq_show = cpu_stats_show,
+		.seq_show = cpu_cfs_stats_show,
+ 	},
+ #endif
+ #ifdef CONFIG_RT_GROUP_SCHED
+@@ -8791,7 +8791,7 @@ struct cgroup_subsys cpu_cgrp_subsys = {
+ 	.fork		= cpu_cgroup_fork,
+ 	.can_attach	= cpu_cgroup_can_attach,
+ 	.attach		= cpu_cgroup_attach,
+-	.legacy_cftypes	= cpu_files,
+	.legacy_cftypes	= cpu_legacy_files,
+ 	.early_init	= true,
+ };
+ 
+diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
+index bc0b309c3f19..d1e5dd0b3a64 100644
+--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
+@@ -276,26 +276,33 @@ static int cpuacct_all_seq_show(struct seq_file *m, void *V)
+ 	return 0;
+ }
+ 
+-static int cpuacct_stats_show(struct seq_file *sf, void *v)
+static void cpuacct_stats_read(struct cpuacct *ca,
+			       u64 (*val)[CPUACCT_STAT_NSTATS])
+ {
+-	struct cpuacct *ca = css_ca(seq_css(sf));
+-	s64 val[CPUACCT_STAT_NSTATS];
+ 	int cpu;
+-	int stat;
+ 
+-	memset(val, 0, sizeof(val));
+	memset(val, 0, sizeof(*val));
+
+ 	for_each_possible_cpu(cpu) {
+ 		u64 *cpustat = per_cpu_ptr(ca->cpustat, cpu)->cpustat;
+ 
+-		val[CPUACCT_STAT_USER]   += cpustat[CPUTIME_USER];
+-		val[CPUACCT_STAT_USER]   += cpustat[CPUTIME_NICE];
+-		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SYSTEM];
+-		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_IRQ];
+-		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SOFTIRQ];
+		(*val)[CPUACCT_STAT_USER]   += cpustat[CPUTIME_USER];
+		(*val)[CPUACCT_STAT_USER]   += cpustat[CPUTIME_NICE];
+		(*val)[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SYSTEM];
+		(*val)[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_IRQ];
+		(*val)[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SOFTIRQ];
+ 	}
+}
+
+static int cpuacct_stats_show(struct seq_file *sf, void *v)
+{
+	u64 val[CPUACCT_STAT_NSTATS];
+	int stat;
+
+	cpuacct_stats_read(css_ca(seq_css(sf)), &val);
+ 
+ 	for (stat = 0; stat < CPUACCT_STAT_NSTATS; stat++) {
+-		seq_printf(sf, "%s %lld\n",
+		seq_printf(sf, "%s %llu\n",
+ 			   cpuacct_stat_desc[stat],
+ 			   cputime64_to_clock_t(val[stat]));
+ 	}
+
+commit 015cbdcb90034fd566d00de9d3d405613da3cd26
+Author: Tejun Heo <tj@kernel.org>
+Date:   Fri Mar 11 07:31:23 2016 -0500
+
+    sched: Implement interface for cgroup unified hierarchy
+    
+    While the cpu controller doesn't have any functional problems, there
+    are a couple interface issues which can be addressed in the v2
+    interface.
+    
+    * cpuacct being a separate controller.  This separation is artificial
+      and rather pointless as demonstrated by most use cases co-mounting
+      the two controllers.  It also forces certain information to be
+      accounted twice.
+    
+    * Use of different time units.  Writable control knobs use
+      microseconds, some stat fields use nanoseconds while other cpuacct
+      stat fields use centiseconds.
+    
+    * Control knobs which can't be used in the root cgroup still show up
+      in the root.
+    
+    * Control knob names and semantics aren't consistent with other
+      controllers.
+    
+    This patchset implements cpu controller's interface on the unified
+    hierarchy which adheres to the controller file conventions described
+    in Documentation/cgroups/unified-hierarchy.txt.  Overall, the
+    following changes are made.
+    
+    * cpuacct is implictly enabled and disabled by cpu and its information
+      is reported through "cpu.stat" which now uses microseconds for all
+      time durations.  All time duration fields now have "_usec" appended
+      to them for clarity.  While this doesn't solve the double accounting
+      immediately, once majority of users switch to v2, cpu can directly
+      account and report the relevant stats and cpuacct can be disabled on
+      the unified hierarchy.
+    
+      Note that cpuacct.usage_percpu is currently not included in
+      "cpu.stat".  If this information is actually called for, it can be
+      added later.
+    
+    * "cpu.shares" is replaced with "cpu.weight" and operates on the
+      standard scale defined by CGROUP_WEIGHT_MIN/DFL/MAX (1, 100, 10000).
+      The weight is scaled to scheduler weight so that 100 maps to 1024
+      and the ratio relationship is preserved - if weight is W and its
+      scaled value is S, W / 100 == S / 1024.  While the mapped range is a
+      bit smaller than the orignal scheduler weight range, the dead zones
+      on both sides are relatively small and covers wider range than the
+      nice value mappings.  This file doesn't make sense in the root
+      cgroup and isn't create on root.
+    
+    * "cpu.cfs_quota_us" and "cpu.cfs_period_us" are replaced by "cpu.max"
+      which contains both quota and period.
+    
+    * "cpu.rt_runtime_us" and "cpu.rt_period_us" are replaced by
+      "cpu.rt.max" which contains both runtime and period.
+    
+    v2: cpu_stats_show() was incorrectly using CONFIG_FAIR_GROUP_SCHED for
+        CFS bandwidth stats and also using raw division for u64.  Use
+        CONFIG_CFS_BANDWITH and do_div() instead.
+    
+        The semantics of "cpu.rt.max" is not fully decided yet.  Dropped
+        for now.
+    
+    Signed-off-by: Tejun Heo <tj@kernel.org>
+    Cc: Ingo Molnar <mingo@redhat.com>
+    Cc: Peter Zijlstra <peterz@infradead.org>
+    Cc: Li Zefan <lizefan@huawei.com>
+    Cc: Johannes Weiner <hannes@cmpxchg.org>
+
+diff --git a/kernel/sched/core.c b/kernel/sched/core.c
+index 57472485b79c..c0ae869f51c4 100644
+--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
+@@ -8784,6 +8784,139 @@ static struct cftype cpu_legacy_files[] = {
+ 	{ }	/* terminate */
+ };
+ 
+static int cpu_stats_show(struct seq_file *sf, void *v)
+{
+	cpuacct_cpu_stats_show(sf);
+
+#ifdef CONFIG_CFS_BANDWIDTH
+	{
+		struct task_group *tg = css_tg(seq_css(sf));
+		struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+		u64 throttled_usec;
+
+		throttled_usec = cfs_b->throttled_time;
+		do_div(throttled_usec, NSEC_PER_USEC);
+
+		seq_printf(sf, "nr_periods %d\n"
+			   "nr_throttled %d\n"
+			   "throttled_usec %llu\n",
+			   cfs_b->nr_periods, cfs_b->nr_throttled,
+			   throttled_usec);
+	}
+#endif
+	return 0;
+}
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static u64 cpu_weight_read_u64(struct cgroup_subsys_state *css,
+			       struct cftype *cft)
+{
+	struct task_group *tg = css_tg(css);
+	u64 weight = scale_load_down(tg->shares);
+
+	return DIV_ROUND_CLOSEST_ULL(weight * CGROUP_WEIGHT_DFL, 1024);
+}
+
+static int cpu_weight_write_u64(struct cgroup_subsys_state *css,
+				struct cftype *cftype, u64 weight)
+{
+	/*
+	 * cgroup weight knobs should use the common MIN, DFL and MAX
+	 * values which are 1, 100 and 10000 respectively.  While it loses
+	 * a bit of range on both ends, it maps pretty well onto the shares
+	 * value used by scheduler and the round-trip conversions preserve
+	 * the original value over the entire range.
+	 */
+	if (weight < CGROUP_WEIGHT_MIN || weight > CGROUP_WEIGHT_MAX)
+		return -ERANGE;
+
+	weight = DIV_ROUND_CLOSEST_ULL(weight * 1024, CGROUP_WEIGHT_DFL);
+
+	return sched_group_set_shares(css_tg(css), scale_load(weight));
+}
+#endif
+
+static void __maybe_unused cpu_period_quota_print(struct seq_file *sf,
+						  long period, long quota)
+{
+	if (quota < 0)
+		seq_puts(sf, "max");
+	else
+		seq_printf(sf, "%ld", quota);
+
+	seq_printf(sf, " %ld\n", period);
+}
+
+/* caller should put the current value in *@periodp before calling */
+static int __maybe_unused cpu_period_quota_parse(char *buf,
+						 u64 *periodp, u64 *quotap)
+{
+	char tok[21];	/* U64_MAX */
+
+	if (!sscanf(buf, "%s %llu", tok, periodp))
+		return -EINVAL;
+
+	*periodp *= NSEC_PER_USEC;
+
+	if (sscanf(tok, "%llu", quotap))
+		*quotap *= NSEC_PER_USEC;
+	else if (!strcmp(tok, "max"))
+		*quotap = RUNTIME_INF;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+#ifdef CONFIG_CFS_BANDWIDTH
+static int cpu_max_show(struct seq_file *sf, void *v)
+{
+	struct task_group *tg = css_tg(seq_css(sf));
+
+	cpu_period_quota_print(sf, tg_get_cfs_period(tg), tg_get_cfs_quota(tg));
+	return 0;
+}
+
+static ssize_t cpu_max_write(struct kernfs_open_file *of,
+			     char *buf, size_t nbytes, loff_t off)
+{
+	struct task_group *tg = css_tg(of_css(of));
+	u64 period = tg_get_cfs_period(tg);
+	u64 quota;
+	int ret;
+
+	ret = cpu_period_quota_parse(buf, &period, &quota);
+	if (!ret)
+		ret = tg_set_cfs_bandwidth(tg, period, quota);
+	return ret ?: nbytes;
+}
+#endif
+
+static struct cftype cpu_files[] = {
+	{
+		.name = "stat",
+		.flags = CFTYPE_NOT_ON_ROOT,
+		.seq_show = cpu_stats_show,
+	},
+#ifdef CONFIG_FAIR_GROUP_SCHED
+	{
+		.name = "weight",
+		.flags = CFTYPE_NOT_ON_ROOT,
+		.read_u64 = cpu_weight_read_u64,
+		.write_u64 = cpu_weight_write_u64,
+	},
+#endif
+#ifdef CONFIG_CFS_BANDWIDTH
+	{
+		.name = "max",
+		.flags = CFTYPE_NOT_ON_ROOT,
+		.seq_show = cpu_max_show,
+		.write = cpu_max_write,
+	},
+#endif
+	{ }	/* terminate */
+};
+
+ struct cgroup_subsys cpu_cgrp_subsys = {
+ 	.css_alloc	= cpu_cgroup_css_alloc,
+ 	.css_released	= cpu_cgroup_css_released,
+@@ -8792,7 +8925,15 @@ struct cgroup_subsys cpu_cgrp_subsys = {
+ 	.can_attach	= cpu_cgroup_can_attach,
+ 	.attach		= cpu_cgroup_attach,
+ 	.legacy_cftypes	= cpu_legacy_files,
+	.dfl_cftypes	= cpu_files,
+ 	.early_init	= true,
+#ifdef CONFIG_CGROUP_CPUACCT
+	/*
+	 * cpuacct is enabled together with cpu on the unified hierarchy
+	 * and its stats are reported through "cpu.stat".
+	 */
+	.depends_on	= 1 << cpuacct_cgrp_id,
+#endif
+ };
+ 
+ #endif	/* CONFIG_CGROUP_SCHED */
+diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
+index d1e5dd0b3a64..57f390514c39 100644
+--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
+@@ -347,6 +347,31 @@ static struct cftype files[] = {
+ 	{ }	/* terminate */
+ };
+ 
+/* used to print cpuacct stats in cpu.stat on the unified hierarchy */
+void cpuacct_cpu_stats_show(struct seq_file *sf)
+{
+	struct cgroup_subsys_state *css;
+	u64 usage, val[CPUACCT_STAT_NSTATS];
+
+	css = cgroup_get_e_css(seq_css(sf)->cgroup, &cpuacct_cgrp_subsys);
+
+	usage = cpuusage_read(css, seq_cft(sf));
+	cpuacct_stats_read(css_ca(css), &val);
+
+	val[CPUACCT_STAT_USER] *= TICK_NSEC;
+	val[CPUACCT_STAT_SYSTEM] *= TICK_NSEC;
+	do_div(usage, NSEC_PER_USEC);
+	do_div(val[CPUACCT_STAT_USER], NSEC_PER_USEC);
+	do_div(val[CPUACCT_STAT_SYSTEM], NSEC_PER_USEC);
+
+	seq_printf(sf, "usage_usec %llu\n"
+		   "user_usec %llu\n"
+		   "system_usec %llu\n",
+		   usage, val[CPUACCT_STAT_USER], val[CPUACCT_STAT_SYSTEM]);
+
+	css_put(css);
+}
+
+ /*
+  * charge this task's execution time to its accounting group.
+  *
+diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h
+index ba72807c73d4..ddf7af466d35 100644
+--- a/kernel/sched/cpuacct.h
+++ b/kernel/sched/cpuacct.h
+@@ -2,6 +2,7 @@
+ 
+ extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
+ extern void cpuacct_account_field(struct task_struct *tsk, int index, u64 val);
+extern void cpuacct_cpu_stats_show(struct seq_file *sf);
+ 
+ #else
+ 
+@@ -14,4 +15,8 @@ cpuacct_account_field(struct task_struct *tsk, int index, u64 val)
+ {
+ }
+ 
+static inline void cpuacct_cpu_stats_show(struct seq_file *sf)
+{
+}
+
+ #endif
+
+commit 5019fe3d7ec456b58d451ef06fe1f81d7d9f28a9
+Author: Tejun Heo <tj@kernel.org>
+Date:   Fri Aug 5 12:41:01 2016 -0400
+
+    cgroup: add documentation regarding CPU controller cgroup v2 support
+    
+    Signed-off-by: Tejun Heo <tj@kernel.org>
+
+diff --git a/Documentation/cgroup-v2-cpu.txt b/Documentation/cgroup-v2-cpu.txt
+new file mode 100644
+index 000000000000..1ed7032d4472
+--- /dev/null
+++ b/Documentation/cgroup-v2-cpu.txt
+@@ -0,0 +1,368 @@
+
+
+CPU Controller on Control Group v2
+
+August, 2016		Tejun Heo <tj@kernel.org>
+
+
+While most controllers have support for cgroup v2 now, the CPU
+controller support is not upstream yet due to objections from the
+scheduler maintainers on the basic designs of cgroup v2.  This
+document explains the current situation as well as an interim
+solution, and details the disagreements and arguments.  The latest
+version of this document can be found at the following URL.
+
+ https://git.kernel.org/cgit/linux/kernel/git/tj/cgroup.git/tree/Documentation/cgroup-v2-cpu.txt?h=cgroup-v2-cpu
+
+This document was posted to the linux-kernel and cgroup mailing lists.
+Unfortunately, no consensus was reached as of Oct, 2016.  The thread
+can be found at the following URL.
+
+ http://lkml.kernel.org/r/20160805170752.GK2542@mtj.duckdns.org
+
+
+CONTENTS
+
+1. Current Situation and Interim Solution
+2. Disagreements and Arguments
+  2-1. Contentious Restrictions
+    2-1-1. Process Granularity
+    2-1-2. No Internal Process Constraint
+  2-2. Impact on CPU Controller
+    2-2-1. Impact of Process Granularity
+    2-2-2. Impact of No Internal Process Constraint
+  2-3. Arguments for cgroup v2
+3. Way Forward
+4. References
+
+
+1. Current Situation and Interim Solution
+
+All objections from the scheduler maintainers apply to cgroup v2 core
+design, and there are no known objections to the specifics of the CPU
+controller cgroup v2 interface.  The only blocked part is changes to
+expose the CPU controller interface on cgroup v2, which comprises the
+following two patches:
+
+ [1] sched: Misc preps for cgroup unified hierarchy interface
+ [2] sched: Implement interface for cgroup unified hierarchy
+
+The necessary changes are superficial and implement the interface
+files on cgroup v2.  The combined diffstat is as follows.
+
+ kernel/sched/core.c    |  149 +++++++++++++++++++++++++++++++++++++++++++++++--
+ kernel/sched/cpuacct.c |   57 ++++++++++++------
+ kernel/sched/cpuacct.h |    5 +
+ 3 files changed, 189 insertions(+), 22 deletions(-)
+
+The patches are easy to apply and forward-port.  The following git
+branch will always carry the two patches on top of the latest release
+of the upstream kernel.
+
+ git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git/cgroup-v2-cpu
+
+There also are versioned branches going back to v4.4.
+
+ git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git/cgroup-v2-cpu-$KERNEL_VER
+
+While it's difficult to tell whether the CPU controller support will
+be merged, there are crucial resource control features in cgroup v2
+that are only possible due to the design choices that are being
+objected to, and every effort will be made to ease enabling the CPU
+controller cgroup v2 support out-of-tree for parties which choose to.
+
+
+2. Disagreements and Arguments
+
+There have been several lengthy discussion threads [3][4] on LKML
+around the structural constraints of cgroup v2.  The two that affect
+the CPU controller are process granularity and no internal process
+constraint.  Both arise primarily from the need for common resource
+domain definition across different resources.
+
+The common resource domain is a powerful concept in cgroup v2 that
+allows controllers to make basic assumptions about the structural
+organization of processes and controllers inside the cgroup hierarchy,
+and thus solve problems spanning multiple types of resources.  The
+prime example for this is page cache writeback: dirty page cache is
+regulated through throttling buffered writers based on memory
+availability, and initiating batched write outs to the disk based on
+IO capacity.  Tracking and controlling writeback inside a cgroup thus
+requires the direct cooperation of the memory and the IO controller.
+
+This easily extends to other areas, such as CPU cycles consumed while
+performing memory reclaim or IO encryption.
+
+
+2-1. Contentious Restrictions
+
+For controllers of different resources to work together, they must
+agree on a common organization.  This uniform model across controllers
+imposes two contentious restrictions on the CPU controller: process
+granularity and the no-internal-process constraint.
+
+
+  2-1-1. Process Granularity
+
+  For memory, because an address space is shared between all threads
+  of a process, the terminal consumer is a process, not a thread.
+  Separating the threads of a single process into different memory
+  control domains doesn't make semantical sense.  cgroup v2 ensures
+  that all controller can agree on the same organization by requiring
+  that threads of the same process belong to the same cgroup.
+
+  There are other reasons to enforce process granularity.  One
+  important one is isolating system-level management operations from
+  in-process application operations.  The cgroup interface, being a
+  virtual filesystem, is very unfit for multiple independent
+  operations taking place at the same time as most operations have to
+  be multi-step and there is no way to synchronize multiple accessors.
+  See also [5] Documentation/cgroup-v2.txt, "R-2. Thread Granularity"
+
+
+  2-1-2. No Internal Process Constraint
+
+  cgroup v2 does not allow processes to belong to any cgroup which has
+  child cgroups when resource controllers are enabled on it (the
+  notable exception being the root cgroup itself).  This is because,
+  for some resources, a resource domain (cgroup) is not directly
+  comparable to the terminal consumer (process/task) of said resource,
+  and so putting the two into a sibling relationship isn't meaningful.
+
+  - Differing Control Parameters and Capabilities
+
+    A cgroup controller has different resource control parameters and
+    capabilities from a terminal consumer, be that a task or process.
+    There are a couple cases where a cgroup control knob can be mapped
+    to a per-task or per-process API but they are exceptions and the
+    mappings aren't obvious even in those cases.
+
+    For example, task priorities (also known as nice values) set
+    through setpriority(2) are mapped to the CPU controller
+    "cpu.shares" values.  However, how exactly the two ranges map and
+    even the fact that they map to each other at all are not obvious.
+
+    The situation gets further muddled when considering other resource
+    types and control knobs.  IO priorities set through ioprio_set(2)
+    cannot be mapped to IO controller weights and most cgroup resource
+    control knobs including the bandwidth control knobs of the CPU
+    controller don't have counterparts in the terminal consumers.
+
+  - Anonymous Resource Consumption
+
+    For CPU, every time slice consumed from inside a cgroup, which
+    comprises most but not all of consumed CPU time for the cgroup,
+    can be clearly attributed to a specific task or process.  Because
+    these two types of entities are directly comparable as consumers
+    of CPU time, it's theoretically possible to mix tasks and cgroups
+    on the same tree levels and let them directly compete for the time
+    quota available to their common ancestor.
+
+    However, the same can't be said for resource types like memory or
+    IO: the memory consumed by the page cache, for example, can be
+    tracked on a per-cgroup level, but due to mismatches in lifetimes
+    of involved objects (page cache can persist long after processes
+    are gone), shared usages and the implementation overhead of
+    tracking persistent state, it can no longer be attributed to
+    individual processes after instantiation.  Consequently, any IO
+    incurred by page cache writeback can be attributed to a cgroup,
+    but not to the individual consumers inside the cgroup.
+
+  For memory and IO, this makes a resource domain (cgroup) an object
+  of a fundamentally different type than a terminal consumer
+  (process).  A process can't be a first class object in the resource
+  distribution graph as its total resource consumption can't be
+  described without the containing resource domain.
+
+  Disallowing processes in internal cgroups avoids competition between
+  cgroups and processes which cannot be meaningfully defined for these
+  resources.  All resource control takes place among cgroups and a
+  terminal consumer interacts with the containing cgroup the same way
+  it would with the system without cgroup.
+
+  Root cgroup is exempt from this constraint, which is in line with
+  how root cgroup is handled in general - it's excluded from cgroup
+  resource accounting and control.
+
+
+Enforcing process granularity and no internal process constraint
+allows all controllers to be on the same footing in terms of resource
+distribution hierarchy.
+
+
+2-2. Impact on CPU Controller
+
+As indicated earlier, the CPU controller's resource distribution graph
+is the simplest.  Every schedulable resource consumption can be
+attributed to a specific task.  In addition, for weight based control,
+the per-task priority set through setpriority(2) can be translated to
+and from a per-cgroup weight.  As such, the CPU controller can treat a
+task and a cgroup symmetrically, allowing support for any tree layout
+of cgroups and tasks.  Both process granularity and the no internal
+process constraint restrict how the CPU controller can be used.
+
+
+  2-2-1. Impact of Process Granularity
+
+  Process granularity prevents tasks belonging to the same process to
+  be assigned to different cgroups.  It was pointed out [6] that this
+  excludes the valid use case of hierarchical CPU distribution within
+  processes.
+
+  To address this issue, the rgroup (resource group) [7][8][9]
+  interface, an extension of the existing setpriority(2) API, was
+  proposed, which is in line with other programmable priority
+  mechanisms and eliminates the risk of in-application configuration
+  and system configuration stepping on each other's toes.
+  Unfortunately, the proposal quickly turned into discussions around
+  cgroup v2 design decisions [4] and no consensus could be reached.
+
+
+  2-2-2. Impact of No Internal Process Constraint
+
+  The no internal process constraint disallows tasks from competing
+  directly against cgroups.  Here is an excerpt from Peter Zijlstra
+  pointing out the issue [10] - R, L and A are cgroups; t1, t2, t3 and
+  t4 are tasks:
+
+
+          R
+        / | \
+       t1 t2 A
+           /   \
+          t3   t4
+
+
+    Is fundamentally different from:
+
+
+               R
+             /   \
+           L       A
+         /   \   /   \
+        t1  t2  t3   t4
+
+
+    Because if in the first hierarchy you add a task (t5) to R, all of
+    its A will run at 1/4th of total bandwidth where before it had
+    1/3rd, whereas with the second example, if you add our t5 to L, A
+    doesn't get any less bandwidth.
+
+
+  It is true that the trees are semantically different from each other
+  and the symmetric handling of tasks and cgroups is aesthetically
+  pleasing.  However, it isn't clear what the practical usefulness of
+  a layout with direct competition between tasks and cgroups would be,
+  considering that number and behavior of tasks are controlled by each
+  application, and cgroups primarily deal with system level resource
+  distribution; changes in the number of active threads would directly
+  impact resource distribution.  Real world use cases of such layouts
+  could not be established during the discussions.
+
+
+2-3. Arguments for cgroup v2
+
+There are strong demands for comprehensive hierarchical resource
+control across all major resources, and establishing a common resource
+hierarchy is an essential step.  As with most engineering decisions,
+common resource hierarchy definition comes with its trade-offs.  With
+cgroup v2, the trade-offs are in the form of structural constraints
+which, among others, restrict the CPU controller's space of possible
+configurations.
+
+However, even with the restrictions, cgroup v2, in combination with
+rgroup, covers most of identified real world use cases while enabling
+new important use cases of resource control across multiple resource
+types that were fundamentally broken previously.
+
+Furthermore, for resource control, treating resource domains as
+objects of a different type from terminal consumers has important
+advantages - it can account for resource consumptions which are not
+tied to any specific terminal consumer, be that a task or process, and
+allows decoupling resource distribution controls from in-application
+APIs.  Even the CPU controller may benefit from it as the kernel can
+consume significant amount of CPU cycles in interrupt context or tasks
+shared across multiple resource domains (e.g. softirq).
+
+Finally, it's important to note that enabling cgroup v2 support for
+the CPU controller doesn't block use cases which require the features
+which are not available on cgroup v2.  Unlikely, but should anybody
+actually rely on the CPU controller's symmetric handling of tasks and
+cgroups, backward compatibility is and will be maintained by being
+able to disconnect the controller from the cgroup v2 hierarchy and use
+it standalone.  This also holds for cpuset which is often used in
+highly customized configurations which might be a poor fit for common
+resource domains.
+
+The required changes are minimal, the benefits for the target use
+cases are critical and obvious, and use cases which have to use v1 can
+continue to do so.
+
+
+3. Way Forward
+
+cgroup v2 primarily aims to solve the problem of comprehensive
+hierarchical resource control across all major computing resources,
+which is one of the core problems of modern server infrastructure
+engineering.  The trade-offs that cgroup v2 took are results of
+pursuing that goal and gaining a better understanding of the nature of
+resource control in the process.
+
+I believe that real world usages will prove cgroup v2's model right,
+considering the crucial pieces of comprehensive resource control that
+cannot be implemented without common resource domains.  This is not to
+say that cgroup v2 is fixed in stone and can't be updated; if there is
+an approach which better serves both comprehensive resource control
+and the CPU controller's flexibility, we will surely move towards
+that.  It goes without saying that discussions around such approach
+should consider practical aspects of resource control as a whole
+rather than absolutely focusing on a particular controller.
+
+Until such consensus can be reached, the CPU controller cgroup v2
+support will be maintained out of the mainline kernel in an easily
+accessible form.  If there is anything cgroup developers can do to
+ease the pain, please feel free to contact us on the cgroup mailing
+list at cgroups@vger.kernel.org.
+
+
+4. References
+
+[1]  http://lkml.kernel.org/r/20160105164834.GE5995@mtj.duckdns.org
+     [PATCH 1/2] sched: Misc preps for cgroup unified hierarchy interface
+     Tejun Heo <tj@kernel.org>
+
+[2]  http://lkml.kernel.org/r/20160105164852.GF5995@mtj.duckdns.org
+     [PATCH 2/2] sched: Implement interface for cgroup unified hierarchy
+     Tejun Heo <tj@kernel.org>
+
+[3]  http://lkml.kernel.org/r/1438641689-14655-4-git-send-email-tj@kernel.org
+     [PATCH 3/3] sched: Implement interface for cgroup unified hierarchy
+     Tejun Heo <tj@kernel.org>
+
+[4]  http://lkml.kernel.org/r/20160407064549.GH3430@twins.programming.kicks-ass.net
+     Re: [PATCHSET RFC cgroup/for-4.6] cgroup, sched: implement resource group and PRIO_RGRP
+     Peter Zijlstra <peterz@infradead.org>
+
+[5]  https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/cgroup-v2.txt
+     Control Group v2
+     Tejun Heo <tj@kernel.org>
+
+[6]  http://lkml.kernel.org/r/CAPM31RJNy3jgG=DYe6GO=wyL4BPPxwUm1f2S6YXacQmo7viFZA@mail.gmail.com
+     Re: [PATCH 3/3] sched: Implement interface for cgroup unified hierarchy
+     Paul Turner <pjt@google.com>
+
+[7]  http://lkml.kernel.org/r/20160105154503.GC5995@mtj.duckdns.org
+     [RFD] cgroup: thread granularity support for cpu controller
+     Tejun Heo <tj@kernel.org>
+
+[8]  http://lkml.kernel.org/r/1457710888-31182-1-git-send-email-tj@kernel.org
+     [PATCHSET RFC cgroup/for-4.6] cgroup, sched: implement resource group and PRIO_RGRP
+     Tejun Heo <tj@kernel.org>
+
+[9]  http://lkml.kernel.org/r/20160311160522.GA24046@htj.duckdns.org
+     Example program for PRIO_RGRP
+     Tejun Heo <tj@kernel.org>
+
+[10] http://lkml.kernel.org/r/20160407082810.GN3430@twins.programming.kicks-ass.net
+     Re: [PATCHSET RFC cgroup/for-4.6] cgroup, sched: implement resource
+     Peter Zijlstra <peterz@infradead.org>
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@ -11716,10 +11716,7 @@ with pkgs;
    kernelPatches =
      [ kernelPatches.bridge_stp_helper
        kernelPatches.p9_fixes
-        # See pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/README.md
-        # when adding a new linux version
-        # !!! 4.7 patch doesn't apply, 4.9 patch not up yet, will keep checking
-        # kernelPatches.cpu-cgroup-v2."4.7"
+        kernelPatches.cpu-cgroup-v2."4.9"
        kernelPatches.modinst_arg_list_too_long
      ]
      ++ lib.optionals ((platform.kernelArch or null) == "mips")
@ -11733,10 +11730,7 @@ with pkgs;
    kernelPatches =
      [ kernelPatches.bridge_stp_helper
        kernelPatches.p9_fixes
-        # See pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/README.md
-        # when adding a new linux version
-        # !!! 4.7 patch doesn't apply, 4.9 patch not up yet, will keep checking
-        # kernelPatches.cpu-cgroup-v2."4.7"
+        kernelPatches.cpu-cgroup-v2."4.10"
        kernelPatches.modinst_arg_list_too_long
      ]
      ++ lib.optionals ((platform.kernelArch or null) == "mips")
@ -11752,8 +11746,7 @@ with pkgs;
        kernelPatches.p9_fixes
        # See pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/README.md
        # when adding a new linux version
-        # !!! 4.7 patch doesn't apply, 4.9 patch not up yet, will keep checking
-        # kernelPatches.cpu-cgroup-v2."4.7"
+        kernelPatches.cpu-cgroup-v2."4.11"
        kernelPatches.modinst_arg_list_too_long
      ]
      ++ lib.optionals ((platform.kernelArch or null) == "mips")