diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2021-11-05 13:40:52 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-06 13:30:38 -0700 |
| commit | 9c25cbfcb38462803a3d68f5d88e66a587f5f045 (patch) | |
| tree | c10a2cb782114aca206f0305a8d93096e378378c | |
| parent | 564f6ea1a689b06284641c12e164f3c5b57f3aaf (diff) | |
mm: page_alloc: use migrate_disable() in drain_local_pages_wq()
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>
| -rw-r--r-- | mm/page_alloc.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6714039cddf4..2aafc337d068 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -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(); } /* |