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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2022-04-01 11:28:33 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-04-01 11:46:09 -0700 |
| commit | adb11e78c5dc5e26774acb05f983da36447f7911 (patch) | |
| tree | bacf697b157f86712edffebbfd7c08aa7d83e966 /mm/rmap.c | |
| parent | 577e9846f8a9e7b09cd356ae0d59a66e19402e8b (diff) | |
| download | lwn-adb11e78c5dc5e26774acb05f983da36447f7911.tar.gz lwn-adb11e78c5dc5e26774acb05f983da36447f7911.zip | |
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 <bigeasy@linutronix.de>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 5cb970d51f0a..fedb82371efe 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1683,7 +1683,7 @@ discard: */ page_remove_rmap(subpage, vma, folio_test_hugetlb(folio)); if (vma->vm_flags & VM_LOCKED) - mlock_page_drain(smp_processor_id()); + mlock_page_drain_local(); folio_put(folio); } @@ -1961,7 +1961,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, */ page_remove_rmap(subpage, vma, folio_test_hugetlb(folio)); if (vma->vm_flags & VM_LOCKED) - mlock_page_drain(smp_processor_id()); + mlock_page_drain_local(); folio_put(folio); } |