scx_lavd: do not inherit parent's properties

If inheriting the parent's properties, a new fork task tends to be too
prioritized. That is, many parent processes, such as `make,` are a bit
more latency-critical than average.

Signed-off-by: Changwoo Min <changwoo@igalia.com>
This commit is contained in:
Changwoo Min 2024-07-19 15:29:13 +09:00
parent 78d96a6fb6
commit b90599e967

View File

@ -1315,7 +1315,6 @@ static u64 calc_virtual_deadline_delta(struct task_struct *p,
struct cpu_ctx *cpuc,
u64 enq_flags)
{
u64 load_factor = get_sys_stat_cur()->load_factor;
u64 vdeadline_delta_ns, weight;
bool is_wakeup;
@ -2833,39 +2832,16 @@ void BPF_STRUCT_OPS(lavd_update_idle, s32 cpu, bool idle)
static void init_task_ctx(struct task_struct *p, struct task_ctx *taskc)
{
struct task_struct *parent;
struct task_ctx *taskc_parent;
u64 now;
u64 now = bpf_ktime_get_ns();
/*
* Inherit parent's statistics if the parent is also under scx.
*/
parent = p->parent;
taskc_parent = try_get_task_ctx(parent);
if (parent && taskc_parent)
memcpy(taskc, taskc_parent, sizeof(*taskc));
else {
/*
* If parent's ctx does not exist, init some fields with
* reasonable defaults.
*/
taskc->run_time_ns = LAVD_SLICE_MIN_NS;
memset(taskc, 0, sizeof(*taskc));
taskc->last_running_clk = now; /* for run_time_ns */
taskc->last_stopping_clk = now; /* for run_time_ns */
taskc->run_time_ns = LAVD_SLICE_MAX_NS;
taskc->lat_prio = get_nice_prio(p);
taskc->run_freq = 1;
}
/*
* Reset context for a fresh new task.
*/
now = bpf_ktime_get_ns();
taskc->last_runnable_clk = now;
taskc->last_running_clk = now;
taskc->last_stopping_clk = now;
taskc->last_quiescent_clk = now;
taskc->run_freq = 0;
taskc->greedy_ratio = 1000;
taskc->victim_cpu = (s32)LAVD_CPU_ID_NONE;
taskc->acc_run_time_ns = 0;
taskc->slice_ns = 0;
}
void BPF_STRUCT_OPS(lavd_enable, struct task_struct *p)