Synchronize with https://github.com/sched-ext/scx at dc44584874f0 ("kernel:
Synchronize with kernel tools/sched_ext").
- READ/WRITE_ONCE() is made more proper and READA_ONCE_ARENA() is dropped.
- scale_by_task_weight[_inverse]() helpers added.
- Enum defs expanded to cover more and new enums.
- Don't trigger fatal error when some enums are missing from kernel BTF.
Signed-off-by: Tejun Heo <tj@kernel.org>
Add where the script is located to the comment lines of the header file.
This helps anyone re-generate the header file if required.
Note that this is a sync from the PR [1] in the scx repo.
[1] https://github.com/sched-ext/scx/pull/1322
Signed-off-by: Changwoo Min <changwoo@igalia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This provides compatible testing of SCX_ENQ_CPU_SELECTED.
More specifically, it handles two cases:
1. a BPF scheduler is compiled against vmlinux.h where
SCX_ENQ_CPU_SELECTED is defined, but it runs on a kernel that does not
have SCX_ENQ_CPU_SELECTED. In this case, the test result of
'enq_flags & SCX_ENQ_CPU_SELECTED' will always be false. That test result
is semantically incorrect because the kernel before SCX_ENQ_CPU_SELECTED
has never skipped select_task_rq_scx(), so the result should be true.
2. a BPF scheduler is compiling against vmlinux.h where
SCX_ENQ_CPU_SELECTED is not defined. In this case, directly using
SCX_ENQ_CPU_SELECTED causes compilation errors.
To hide such complexity, introduce __COMPAT_is_enq_cpu_selected(),
which checks if SCX_ENQ_CPU_SELECTED exists in runtime using BPF CO-RE.
This consists of three parts:
1. Add enum_defs.autogen.h, which has macros (HAVE_{enum name}) denoting
whether SCX enums are defined in the vmlinux.h or not.
2. Implement __COMPAT_is_enq_cpu_selected(), which provide the test of
SCX_ENQ_CPU_SELECTED in a compatible way.
3. Use __COMPAT_is_enq_cpu_selected() in scx_qmap.
Note that this is a sync of the relevant PR [1] in the scx repo.
[1] https://github.com/sched-ext/scx/pull/1314
Signed-off-by: Changwoo Min <changwoo@igalia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
