diff options
| author | Changwoo Min <changwoo@igalia.com> | 2026-04-29 17:23:18 +0900 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2026-04-28 22:44:34 -1000 |
| commit | ee8391ba11644fd3dce6e22ece54725a1bb5b50e (patch) | |
| tree | 2b0b0379bbe3ccf918883b56b8e907c4fa17ff88 /tools/sched_ext | |
| parent | 78683079ca6d91392e84ed313e15bb330d7da851 (diff) | |
sched_ext: Expose exit_cpu to BPF and userspace
Extend struct user_exit_info with an exit_cpu field so BPF schedulers
and the userspace report path can see the CPU that triggered the exit,
matching the kernel-side dump.
UEI_RECORD() defaults the field to -1 before the CO-RE-gated copy so
that running against an older kernel without exit_cpu stays
distinguishable from "exit happened on CPU 0".
UEI_REPORT() appends "on CPU N" to the EXIT line when the value is
valid, surfacing the most diagnostically useful piece of exit info to
any sched_ext userspace tool without needing to crack open the debug
dump.
Signed-off-by: Changwoo Min <changwoo@igalia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'tools/sched_ext')
| -rw-r--r-- | tools/sched_ext/include/scx/user_exit_info.bpf.h | 3 | ||||
| -rw-r--r-- | tools/sched_ext/include/scx/user_exit_info.h | 2 | ||||
| -rw-r--r-- | tools/sched_ext/include/scx/user_exit_info_common.h | 5 |
3 files changed, 10 insertions, 0 deletions
diff --git a/tools/sched_ext/include/scx/user_exit_info.bpf.h b/tools/sched_ext/include/scx/user_exit_info.bpf.h index e7ac6611a990..98cab643c8d9 100644 --- a/tools/sched_ext/include/scx/user_exit_info.bpf.h +++ b/tools/sched_ext/include/scx/user_exit_info.bpf.h @@ -32,6 +32,9 @@ __uei_name##_dump_len, (__ei)->dump); \ if (bpf_core_field_exists((__ei)->exit_code)) \ __uei_name.exit_code = (__ei)->exit_code; \ + __uei_name.exit_cpu = -1; \ + if (bpf_core_field_exists((__ei)->exit_cpu)) \ + __uei_name.exit_cpu = (__ei)->exit_cpu; \ /* use __sync to force memory barrier */ \ __sync_val_compare_and_swap(&__uei_name.kind, __uei_name.kind, \ (__ei)->kind); \ diff --git a/tools/sched_ext/include/scx/user_exit_info.h b/tools/sched_ext/include/scx/user_exit_info.h index 399697fa372f..56a02b549aef 100644 --- a/tools/sched_ext/include/scx/user_exit_info.h +++ b/tools/sched_ext/include/scx/user_exit_info.h @@ -39,6 +39,8 @@ fprintf(stderr, "EXIT: %s", __uei->reason); \ if (__uei->msg[0] != '\0') \ fprintf(stderr, " (%s)", __uei->msg); \ + if (__uei->exit_cpu >= 0) \ + fprintf(stderr, " on CPU %d", __uei->exit_cpu); \ fputs("\n", stderr); \ __uei->exit_code; \ }) diff --git a/tools/sched_ext/include/scx/user_exit_info_common.h b/tools/sched_ext/include/scx/user_exit_info_common.h index 2d0981aedd89..76e2a055eb4b 100644 --- a/tools/sched_ext/include/scx/user_exit_info_common.h +++ b/tools/sched_ext/include/scx/user_exit_info_common.h @@ -22,6 +22,11 @@ enum uei_sizes { struct user_exit_info { int kind; + /* + * CPU that triggered the exit, or -1 if unset (e.g. running on an + * older kernel that does not expose this field). + */ + s32 exit_cpu; s64 exit_code; char reason[UEI_REASON_LEN]; char msg[UEI_MSG_LEN]; |