From 0a47eb2220c5056863f5c367c3e3d87d1c5e980f Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Fri, 30 Sep 2022 18:08:40 +0800 Subject: [PATCH] sched: Teach the forced-newidle balancer about CPU affinity limitation. mainline inclusion from mainline-v5.18-rc2 commit 386ef214c3c6ab111d05e1790e79475363abaa05 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5OOWG CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=386ef214c3c6ab111d05e1790e79475363abaa05 -------------------------------------------------------------------------- try_steal_cookie() looks at task_struct::cpus_mask to decide if the task could be moved to `this' CPU. It ignores that the task might be in a migration disabled section while not on the CPU. In this case the task must not be moved otherwise per-CPU assumption are broken. Use is_cpu_allowed(), as suggested by Peter Zijlstra, to decide if the a task can be moved. Fixes: d2dfa17bc7de6 ("sched: Trivial forced-newidle balancer") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/YjNK9El+3fzGmswf@linutronix.de Signed-off-by: Lin Shengwang Reviewed-by: lihua Signed-off-by: Zheng Zengkai --- kernel/sched/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 1341087361ac..b310748225ed 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5045,7 +5045,7 @@ static bool try_steal_cookie(int this, int that) if (p == src->core_pick || p == src->curr) goto next; - if (!cpumask_test_cpu(this, &p->cpus_mask)) + if (!is_cpu_allowed(p, this)) goto next; if (p->core_occupation > dst->idle->core_occupation) -- GitLab