Messages in this thread | | | Date | Fri, 3 Feb 2023 17:13:02 -0500 | Subject | Re: [PATCH] sched/core: Fix a missed update of user_cpus_ptr | From | Waiman Long <> |
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On 2/3/23 16:04, Tejun Heo wrote: > On Fri, Feb 03, 2023 at 01:18:49PM -0500, Waiman Long wrote: >> Since commit 8f9ea86fdf99 ("sched: Always preserve the user requested >> cpumask"), a successful call to sched_setaffinity() should always save >> the user requested cpu affinity mask in a task's user_cpus_ptr. However, >> when the given cpu mask is the same as the current one, user_cpus_ptr >> is not updated. Fix this by saving the user mask in this case too. >> >> Fixes: 8f9ea86fdf99 ("sched: Always preserve the user requested cpumask") >> Signed-off-by: Waiman Long <longman@redhat.com> >> --- >> kernel/sched/core.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/kernel/sched/core.c b/kernel/sched/core.c >> index 30d9752e2ca5..91255f791df3 100644 >> --- a/kernel/sched/core.c >> +++ b/kernel/sched/core.c >> @@ -2951,8 +2951,11 @@ static int __set_cpus_allowed_ptr_locked(struct task_struct *p, >> } >> >> if (!(ctx->flags & SCA_MIGRATE_ENABLE)) { >> - if (cpumask_equal(&p->cpus_mask, ctx->new_mask)) >> + if (cpumask_equal(&p->cpus_mask, ctx->new_mask)) { >> + if (ctx->flags & SCA_USER) >> + swap(p->user_cpus_ptr, ctx->user_mask); >> goto out; >> + } >> >> if (WARN_ON_ONCE(p == current && >> is_migration_disabled(p) && > and this is for a separate bug and should go through the scheduler tree.
Yes, this is for Peter to pick up.
Cheers, Longman
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