From 9d0df37797453f168afdb2e6fd0353c73718ae9a Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Mon, 29 Nov 2021 18:46:44 +0100 Subject: [PATCH] sched: Trigger warning if ->migration_disabled counter underflows. If migrate_enable() is used more often than its counter part then it remains undetected and rq::nr_pinned will underflow, too. Add a warning if migrate_enable() is attempted if without a matching a migrate_disable(). Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20211129174654.668506-2-bigeasy@linutronix.de --- kernel/sched/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 3c9b0fda64ac..300218ad98a2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2173,6 +2173,9 @@ void migrate_enable(void) return; } + if (WARN_ON_ONCE(!p->migration_disabled)) + return; + /* * Ensure stop_task runs either before or after this, and that * __set_cpus_allowed_ptr(SCA_MIGRATE_ENABLE) doesn't schedule().