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| author | Wanwu Li <liwanwu@kylinos.cn> | 2026-08-27 16:07:36 +0800 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2026-08-31 06:47:26 -1000 |
| commit | 23761359861ca4bb087540937dfea8b0716914c2 (patch) | |
| tree | ee3f9a3358103a2a99d1db6f322ba067efb88929 | |
| parent | 6586705bc2dc06908309bf65d79efa53a347c9f0 (diff) | |
| download | linux-23761359861ca4bb087540937dfea8b0716914c2.tar.gz linux-23761359861ca4bb087540937dfea8b0716914c2.zip | |
sched_ext: Fix timer pinning and return value in scx_central
central_timerfn() re-arms the timer with a hardcoded
BPF_F_TIMER_CPU_PIN flag and ignores the return value, defeating
start_central_timer()'s -EINVAL fallback for kernels without the flag
(<6.7): on such kernels the first tick kills the timer permanently
with no diagnostic. Honor timer_pinned and check the return like
the initial arm does.
Fixes: 22a920209ab6 ("sched_ext: Implement tickless support")
Signed-off-by: Wanwu Li <liwanwu@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
| -rw-r--r-- | tools/sched_ext/scx_central.bpf.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/tools/sched_ext/scx_central.bpf.c b/tools/sched_ext/scx_central.bpf.c index 64dd60b3e922..65dae9e45400 100644 --- a/tools/sched_ext/scx_central.bpf.c +++ b/tools/sched_ext/scx_central.bpf.c @@ -299,6 +299,7 @@ static int central_timerfn(void *map, int *key, struct bpf_timer *timer) u64 now = scx_bpf_now(); u64 nr_to_kick = nr_queued; s32 i, curr_cpu; + int ret; curr_cpu = bpf_get_smp_processor_id(); if (timer_pinned && (curr_cpu != central_cpu)) { @@ -332,7 +333,10 @@ static int central_timerfn(void *map, int *key, struct bpf_timer *timer) scx_bpf_kick_cpu(cpu, SCX_KICK_PREEMPT); } - bpf_timer_start(timer, TIMER_INTERVAL_NS, BPF_F_TIMER_CPU_PIN); + ret = bpf_timer_start(timer, TIMER_INTERVAL_NS, + timer_pinned ? BPF_F_TIMER_CPU_PIN : 0); + if (ret) + scx_bpf_error("bpf_timer_start failed (%d)", ret); __sync_fetch_and_add(&nr_timers, 1); return 0; } |