From 09d09da2b8c97fd09f50deb278f9d4a25b99ad55 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 17 Nov 2020 12:14:51 +0100 Subject: [PATCH 022/323] sched: Fix migration_cpu_stop() WARN Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz Oleksandr reported hitting the WARN in the 'task_rq(p) != rq' branch of migration_cpu_stop(). Valentin noted that using cpu_of(rq) in that case is just plain wrong to begin with, since per the earlier branch that isn't the actual CPU of the task. Replace both instances of is_cpu_allowed() by a direct p->cpus_mask test using task_cpu(). Reported-by: Oleksandr Natalenko Debugged-by: Valentin Schneider Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Sebastian Andrzej Siewior --- kernel/sched/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index d12d91510789..7d67a0e03f9a 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1929,7 +1929,7 @@ static int migration_cpu_stop(void *data) * and we should be valid again. Nothing to do. */ if (!pending) { - WARN_ON_ONCE(!is_cpu_allowed(p, cpu_of(rq))); + WARN_ON_ONCE(!cpumask_test_cpu(task_cpu(p), &p->cpus_mask)); goto out; } @@ -1957,7 +1957,7 @@ static int migration_cpu_stop(void *data) * valid again. Nothing to do. */ if (!pending) { - WARN_ON_ONCE(!is_cpu_allowed(p, cpu_of(rq))); + WARN_ON_ONCE(!cpumask_test_cpu(task_cpu(p), &p->cpus_mask)); goto out; } -- 2.43.0