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| author | Mel Gorman <mgorman@suse.de> | 2012-01-12 17:19:34 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-12 20:13:09 -0800 |
| commit | b969c4ab9f182a6e1b2a0848be349f99714947b0 (patch) | |
| tree | dc1c6e4375cfec7b15f13a37307eba8a9e07f40f /include/linux/fs.h | |
| parent | 7335084d446b83cbcb15da80497d03f0c1dc9e21 (diff) | |
| download | op-kernel-dev-b969c4ab9f182a6e1b2a0848be349f99714947b0.zip op-kernel-dev-b969c4ab9f182a6e1b2a0848be349f99714947b0.tar.gz | |
mm: compaction: determine if dirty pages can be migrated without blocking within ->migratepage
Asynchronous compaction is used when allocating transparent hugepages to
avoid blocking for long periods of time. Due to reports of stalling,
there was a debate on disabling synchronous compaction but this severely
impacted allocation success rates. Part of the reason was that many dirty
pages are skipped in asynchronous compaction by the following check;
if (PageDirty(page) && !sync &&
mapping->a_ops->migratepage != migrate_page)
rc = -EBUSY;
This skips over all mapping aops using buffer_migrate_page() even though
it is possible to migrate some of these pages without blocking. This
patch updates the ->migratepage callback with a "sync" parameter. It is
the responsibility of the callback to fail gracefully if migration would
block.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/fs.h')
| -rw-r--r-- | include/linux/fs.h | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index a7409bc..b92b73d 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -609,9 +609,12 @@ struct address_space_operations { loff_t offset, unsigned long nr_segs); int (*get_xip_mem)(struct address_space *, pgoff_t, int, void **, unsigned long *); - /* migrate the contents of a page to the specified target */ + /* + * migrate the contents of a page to the specified target. If sync + * is false, it must not block. + */ int (*migratepage) (struct address_space *, - struct page *, struct page *); + struct page *, struct page *, bool); int (*launder_page) (struct page *); int (*is_partially_uptodate) (struct page *, read_descriptor_t *, unsigned long); @@ -2537,7 +2540,7 @@ extern int generic_check_addressable(unsigned, u64); #ifdef CONFIG_MIGRATION extern int buffer_migrate_page(struct address_space *, - struct page *, struct page *); + struct page *, struct page *, bool); #else #define buffer_migrate_page NULL #endif |
