SCX_KICK_IDLE is a new feature which isn't defined in older kernels. Add
compat wrapper and use it for idle CPU wakeups.
Signed-off-by: Tejun Heo <tj@kernel.org>
In the latest kernel, sched_ext API has changed in two areas:
- ops.prep_enable/cancel_enable/enable/disable() replaced with
ops.init_task/enable/disable/exit_task().
- scx_bpf_dispatch() can now be called from ops.select_cpu(). Also,
SCX_ENQ_LOCAL flag is removed. Instead, users can call
scx_bpf_select_cpu_dfl() from ops.select_cpu() and use the @is_idle out
param value to determine whether to dispatch directly.
This commit updates all schedules so that they build.
- Init functions renamed / merged / split.
- ops.select_cpu() is added to several schedulers and local direct
disptching logic is moved there.
This is the minimum update which is need to make the schedulers build and
work. It needs further update to e.g. move vtime udpates to ops.enable().
Improve build portability by including asm-generic/errno.h, instead of
linux/errno.h.
The difference between these two headers can be summarized as following:
- asm-generic/errno.h contains generic error code definitions that are
intended to be common across different architectures,
- linux/errno.h includes architecture-specific error codes and
provides additional (or overrides) error code definitions based on
the specific architecture where the code is compiled.
Considering the architecture-independent nature of scx, the advantages
of being able to use architecture-specific error codes are marginal or
negligible (and we should probably discourage using them).
Moving towards asm-generic/errno.h, however, allows the removal of
cross-compilation dependencies (such as the gcc-multilib package in
Debian/Ubuntu) and improves the code portability across various
architectures and distributions.
This also allows to remove a symlink hack from the github workflow.
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>