mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-27 12:57:53 +00:00
Code Issues Releases Wiki Activity

mm: page_alloc: use migrate_disable() in drain_local_pages_wq()

Browse source 
drain_local_pages_wq() disables preemption to avoid CPU migration during
CPU hotplug and can't use cpus_read_lock().

Using migrate_disable() works here, too.  The scheduler won't take the
CPU offline until the task left the migrate-disable section.  The
problem with disabled preemption here is that drain_local_pages()
acquires locks which are turned into sleeping locks on PREEMPT_RT and
can't be acquired with disabled preemption.

Use migrate_disable() in drain_local_pages_wq().

Link: https://lkml.kernel.org/r/20211015210933.viw6rjvo64qtqxn4@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Sebastian Andrzej Siewior 2021-11-05 13:40:52 -07:00 committed by Linus Torvalds
parent 564f6ea1a6
commit 9c25cbfcb3
1 changed files with 2 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
mm/page_alloc.c
View file

@ -3141,9 +3141,9 @@ static void drain_local_pages_wq(struct work_struct *work)
* cpu which is alright but we also have to make sure to not move to
* a different one.
*/
preempt_disable();
migrate_disable();
drain_local_pages(drain->zone);
preempt_enable();
migrate_enable();
}
/*