Messages in this thread Patch in this message | | | From | Hao Jia <> | Subject | [PATCH v3 2/4] sched/core: Avoid double calling update_rq_clock() in __balance_push_cpu_stop() | Date | Mon, 15 May 2023 14:38:46 +0800 |
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The WARN_DOUBLE_CLOCK warning is triggered during cpu offline. ------------[ cut here ]------------ rq->clock_update_flags & RQCF_UPDATED WARNING: CPU: 17 PID: 138 at kernel/sched/core.c:741 update_rq_clock+0xaf/0x180 Call Trace: <TASK> __balance_push_cpu_stop+0x146/0x180 ? migration_cpu_stop+0x2a0/0x2a0 cpu_stopper_thread+0xa3/0x140 smpboot_thread_fn+0x14f/0x210 ? sort_range+0x20/0x20 kthread+0xe6/0x110 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30
To avoid this warning, we remove update_rq_clock() from the __migrate_task() function. And in order to avoid missing rq clock update, add update_rq_clock() call before migration_cpu_stop() calls __migrate_task().
Signed-off-by: Hao Jia <jiahao.os@bytedance.com> --- kernel/sched/core.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 944c3ae39861..2bcf6a8e71fc 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2398,7 +2398,6 @@ static struct rq *__migrate_task(struct rq *rq, struct rq_flags *rf, if (!is_cpu_allowed(p, dest_cpu)) return rq; - update_rq_clock(rq); rq = move_queued_task(rq, rf, p, dest_cpu); return rq; @@ -2456,10 +2455,12 @@ static int migration_cpu_stop(void *data) goto out; } - if (task_on_rq_queued(p)) + if (task_on_rq_queued(p)) { + update_rq_clock(rq); rq = __migrate_task(rq, &rf, p, arg->dest_cpu); - else + } else { p->wake_cpu = arg->dest_cpu; + } /* * XXX __migrate_task() can fail, at which point we might end -- 2.37.0
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