mm: accelerate munlock() treatment of THP pages

munlock_vma_pages_range() was always incrementing addresses by PAGE_SIZE
at a time.  When munlocking THP pages (or the huge zero page), this
resulted in taking the mm->page_table_lock 512 times in a row.

We can do better by making use of the page_mask returned by
follow_page_mask (for the huge zero page case), or the size of the page
munlock_vma_page() operated on (for the true THP page case).

Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michel Lespinasse
2013-02-27 17:02:44 -08:00
committed by Linus Torvalds
parent c5a51053cf
commit ff6a6da60b
2 changed files with 24 additions and 12 deletions
+1 -1
View File
@@ -195,7 +195,7 @@ static inline int mlocked_vma_newpage(struct vm_area_struct *vma,
* must be called with vma's mmap_sem held for read or write, and page locked.
*/
extern void mlock_vma_page(struct page *page);
extern void munlock_vma_page(struct page *page);
extern unsigned int munlock_vma_page(struct page *page);
/*
* Clear the page's PageMlocked(). This can be useful in a situation where