diff options
| author | Tejun Heo <tj@kernel.org> | 2026-04-29 08:09:10 -1000 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2026-04-29 08:25:07 -1000 |
| commit | df7b5ae038d6f2707ec0f81c257a55b4062f77c7 (patch) | |
| tree | cca786b2186e6ec8fc35fd0cdbb81d4b69d60e97 /tools/sched_ext | |
| parent | e9b55af47edf6e60c9a47b5604c3e15c5162ec86 (diff) | |
sched_ext: Add scx_bpf_cid_override() kfunc
The auto-probed cid mapping reflects the kernel's view of topology
(node -> LLC -> core), but a BPF scheduler may want a different layout -
to align cid slices with its own partitioning, or to work around how the
kernel reports a particular machine.
Add scx_bpf_cid_override(), callable from ops.init() of the root
scheduler. It validates the caller-supplied cpu->cid array and replaces
the in-place mapping; topo info is invalidated. A compat.bpf.h wrapper
silently no-ops on kernels that lack the kfunc.
A new SCX_KF_ALLOW_INIT bit in the kfunc context filter restricts the
kfunc to ops.init() at verifier load time.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Reviewed-by: Changwoo Min <changwoo@igalia.com>
Diffstat (limited to 'tools/sched_ext')
| -rw-r--r-- | tools/sched_ext/include/scx/compat.bpf.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/tools/sched_ext/include/scx/compat.bpf.h b/tools/sched_ext/include/scx/compat.bpf.h index 2808003eef04..6b9d054c3e4f 100644 --- a/tools/sched_ext/include/scx/compat.bpf.h +++ b/tools/sched_ext/include/scx/compat.bpf.h @@ -121,6 +121,18 @@ static inline bool scx_bpf_sub_dispatch(u64 cgroup_id) return false; } +/* + * v7.2: scx_bpf_cid_override() for explicit cpu->cid mapping. Ignore if + * missing. + */ +void scx_bpf_cid_override___compat(const s32 *cpu_to_cid, u32 cpu_to_cid__sz) __ksym __weak; + +static inline void scx_bpf_cid_override(const s32 *cpu_to_cid, u32 cpu_to_cid__sz) +{ + if (bpf_ksym_exists(scx_bpf_cid_override___compat)) + return scx_bpf_cid_override___compat(cpu_to_cid, cpu_to_cid__sz); +} + /** * __COMPAT_is_enq_cpu_selected - Test if SCX_ENQ_CPU_SELECTED is on * in a compatible way. We will preserve this __COMPAT helper until v6.16. |