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| author | Michel Lespinasse <walken@google.com> | 2011-01-13 15:46:11 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 17:32:36 -0800 |
| commit | 110d74a921f4d272b47ef6104fcf937df808f4c8 (patch) | |
| tree | a2f1705e049f06e1cf8cbaf7d6b3261f0b46b6ab /mm/memory.c | |
| parent | fed067da46ad3b9acedaf794a5f05d0bc153280b (diff) | |
| download | kernel-common-110d74a921f4d272b47ef6104fcf937df808f4c8.tar.gz kernel-common-110d74a921f4d272b47ef6104fcf937df808f4c8.tar.bz2 kernel-common-110d74a921f4d272b47ef6104fcf937df808f4c8.zip | |
mm: add FOLL_MLOCK follow_page flag.
Move the code to mlock pages from __mlock_vma_pages_range() to
follow_page().
This allows __mlock_vma_pages_range() to not have to break down work into
16-page batches.
An additional motivation for doing this within the present patch series is
that it'll make it easier for a later chagne to drop mmap_sem when
blocking on disk (we'd like to be able to resume at the page that was read
from disk instead of at the start of a 16-page batch).
Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c index b8f97b8575b7..15e1f19a3b10 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1310,6 +1310,28 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, */ mark_page_accessed(page); } + if (flags & FOLL_MLOCK) { + /* + * The preliminary mapping check is mainly to avoid the + * pointless overhead of lock_page on the ZERO_PAGE + * which might bounce very badly if there is contention. + * + * If the page is already locked, we don't need to + * handle it now - vmscan will handle it later if and + * when it attempts to reclaim the page. + */ + if (page->mapping && trylock_page(page)) { + lru_add_drain(); /* push cached pages to LRU */ + /* + * Because we lock page here and migration is + * blocked by the pte's page reference, we need + * only check for file-cache page truncation. + */ + if (page->mapping) + mlock_vma_page(page); + unlock_page(page); + } + } unlock: pte_unmap_unlock(ptep, ptl); out: |