diff options
Diffstat (limited to 'patches/sched-Prevent-balance_push-on-remote-runqueues.patch')
| -rw-r--r-- | patches/sched-Prevent-balance_push-on-remote-runqueues.patch | 61 |
1 files changed, 0 insertions, 61 deletions
diff --git a/patches/sched-Prevent-balance_push-on-remote-runqueues.patch b/patches/sched-Prevent-balance_push-on-remote-runqueues.patch deleted file mode 100644 index 28b0c9ee5143..000000000000 --- a/patches/sched-Prevent-balance_push-on-remote-runqueues.patch +++ /dev/null @@ -1,61 +0,0 @@ -From: Thomas Gleixner <tglx@linutronix.de> -Subject: sched: Prevent balance_push() on remote runqueues -Date: Sat, 28 Aug 2021 15:55:52 +0200 - -sched_setscheduler() and rt_mutex_setprio() invoke the run-queue balance -callback after changing priorities or the scheduling class of a task. The -run-queue for which the callback is invoked can be local or remote. - -That's not a problem for the regular rq::push_work which is serialized with -a busy flag in the run-queue struct, but for the balance_push() work which -is only valid to be invoked on the outgoing CPU that's wrong. It not only -triggers the debug warning, but also leaves the per CPU variable push_work -unprotected, which can result in double enqueues on the stop machine list. - -Remove the warning and validate that the function is invoked on the -outgoing CPU. - -Fixes: ae7927023243 ("sched: Optimize finish_lock_switch()") -Reported-by: Sebastian Siewior <bigeasy@linutronix.de> -Signed-off-by: Thomas Gleixner <tglx@linutronix.de> -Cc: stable@vger.kernel.org -Cc: Juri Lelli <juri.lelli@redhat.com> -Cc: Vincent Guittot <vincent.guittot@linaro.org> -Cc: Peter Zijlstra <peterz@infradead.org> -Cc: Steven Rostedt <rostedt@goodmis.org> -Cc: Ben Segall <bsegall@google.com> -Cc: Ingo Molnar <mingo@kernel.org> -Cc: Mel Gorman <mgorman@suse.de> -Cc: Daniel Bristot de Oliveira <bristot@redhat.com> -Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> -Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> -Link: https://lore.kernel.org/r/87zgt1hdw7.ffs@tglx ---- -V2: Use the correct check for the outgoing CPU ---- - kernel/sched/core.c | 6 +++--- - 1 file changed, 3 insertions(+), 3 deletions(-) - ---- a/kernel/sched/core.c -+++ b/kernel/sched/core.c -@@ -8523,7 +8523,6 @@ static void balance_push(struct rq *rq) - struct task_struct *push_task = rq->curr; - - lockdep_assert_rq_held(rq); -- SCHED_WARN_ON(rq->cpu != smp_processor_id()); - - /* - * Ensure the thing is persistent until balance_push_set(.on = false); -@@ -8531,9 +8530,10 @@ static void balance_push(struct rq *rq) - rq->balance_callback = &balance_push_callback; - - /* -- * Only active while going offline. -+ * Only active while going offline and when invoked on the outgoing -+ * CPU. - */ -- if (!cpu_dying(rq->cpu)) -+ if (!cpu_dying(rq->cpu) || rq != this_rq()) - return; - - /* |