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| author | Jacobo Giralt <jacobo.giralt@gmail.com> | 2012-01-10 15:07:11 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-10 16:30:41 -0800 |
| commit | 937a94c9db30a818baa5e2c09dbf4589251355c3 (patch) | |
| tree | c038d9689edf1f03467227959f66c3ef750a9572 | |
| parent | 90a5d5af74f6570af063fb6bff33c6b2f8361bbc (diff) | |
| download | linux-937a94c9db30a818baa5e2c09dbf4589251355c3.tar.gz | |
mm: migrate: one less atomic operation
migrate_page_move_mapping() drops a reference from the old page after unfreezing its counter. Both operations can be merged into a single atomic operation by directly unfreezing to one less reference. The same applies to migrate_huge_page_move_mapping(). Signed-off-by: Jacobo Giralt <jacobo.giralt@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Minchan Kim <minchan.kim@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>
| -rw-r--r-- | mm/migrate.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 177aca424a06..594dc375d0f9 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -269,12 +269,12 @@ static int migrate_page_move_mapping(struct address_space *mapping, radix_tree_replace_slot(pslot, newpage); - page_unfreeze_refs(page, expected_count); /* - * Drop cache reference from old page. + * Drop cache reference from old page by unfreezing + * to one less reference. * We know this isn't the last reference. */ - __put_page(page); + page_unfreeze_refs(page, expected_count - 1); /* * If moved to a different zone then also account @@ -334,9 +334,7 @@ int migrate_huge_page_move_mapping(struct address_space *mapping, radix_tree_replace_slot(pslot, newpage); - page_unfreeze_refs(page, expected_count); - - __put_page(page); + page_unfreeze_refs(page, expected_count - 1); spin_unlock_irq(&mapping->tree_lock); return 0; |