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| author | Tejun Heo <tj@kernel.org> | 2026-07-27 11:20:32 -1000 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2026-07-27 11:20:32 -1000 |
| commit | e06ece82d7b078b511d36fbaca46df231c647e16 (patch) | |
| tree | a290a669cf5d85649a4f6a316723a7f7f0877ed2 | |
| parent | 1bf623ebd50315260ce6da9601e4cd3e79659152 (diff) | |
| download | linux-next-e06ece82d7b078b511d36fbaca46df231c647e16.tar.gz linux-next-e06ece82d7b078b511d36fbaca46df231c647e16.zip | |
sched_ext: Report NMI kicks with scx_error()
The per-cpu kick lists are protected by IRQ masking which doesn't stop NMIs,
so scx_bpf_kick_cpu() from NMI silently drops the kick after a one-time
warning. A dropped kick can leave a CPU idle when the scheduler believes it
was woken, which is a correctness problem for the scheduler even if the
kernel is fine. Now that scx_error() works from NMI, abort the scheduler
instead so that the bug is surfaced deterministically. The warned_nmi_kick
tracking is no longer needed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
| -rw-r--r-- | kernel/sched/ext/ext.c | 6 | ||||
| -rw-r--r-- | kernel/sched/ext/internal.h | 1 |
2 files changed, 1 insertions, 6 deletions
diff --git a/kernel/sched/ext/ext.c b/kernel/sched/ext/ext.c index cc526776b3cc..cff55fa3d58f 100644 --- a/kernel/sched/ext/ext.c +++ b/kernel/sched/ext/ext.c @@ -9219,11 +9219,7 @@ void scx_kick_cpu(struct scx_sched *sch, s32 cpu, u64 flags) * not mask NMIs, so kicking from NMI could corrupt it and is unsupported. */ if (unlikely(in_nmi())) { - if (!sch->warned_nmi_kick) { - sch->warned_nmi_kick = true; - pr_warn("sched_ext: %s: scx_bpf_kick_cpu() from NMI ignored\n", - sch->ops.name); - } + scx_error(sch, "scx_bpf_kick_cpu() called from NMI"); return; } diff --git a/kernel/sched/ext/internal.h b/kernel/sched/ext/internal.h index 5b73ffb0251a..7501ec28958b 100644 --- a/kernel/sched/ext/internal.h +++ b/kernel/sched/ext/internal.h @@ -1543,7 +1543,6 @@ struct scx_sched { */ bool warned_zero_slice:1; bool warned_unassoc_progs:1; - bool warned_nmi_kick:1; struct list_head all; |