From adb11e78c5dc5e26774acb05f983da36447f7911 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Fri, 1 Apr 2022 11:28:33 -0700 Subject: mm/munlock: protect the per-CPU pagevec by a local_lock_t The access to mlock_pvec is protected by disabling preemption via get_cpu_var() or implicit by having preemption disabled by the caller (in mlock_page_drain() case). This breaks on PREEMPT_RT since folio_lruvec_lock_irq() acquires a sleeping lock in this section. Create struct mlock_pvec which consits of the local_lock_t and the pagevec. Acquire the local_lock() before accessing the per-CPU pagevec. Replace mlock_page_drain() with a _local() version which is invoked on the local CPU and acquires the local_lock_t and a _remote() version which uses the pagevec from a remote CPU which offline. Link: https://lkml.kernel.org/r/YjizWi9IY0mpvIfb@linutronix.de Signed-off-by: Sebastian Andrzej Siewior Acked-by: Hugh Dickins Cc: Vlastimil Babka Cc: Matthew Wilcox Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 1 + 1 file changed, 1 insertion(+) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6c6af8658775..2db95780e003 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8367,6 +8367,7 @@ static int page_alloc_cpu_dead(unsigned int cpu) struct zone *zone; lru_add_drain_cpu(cpu); + mlock_page_drain_remote(cpu); drain_pages(cpu); /* -- cgit v1.2.3