[PATCH 33/97] mm, compaction: determine isolation mode only once
From: Mel Gorman <mgorman@suse.de>
Date: 2014-08-28 19:03:48
Also in:
lkml
Subsystem:
memory management, memory management - page allocator, the rest · Maintainers:
Andrew Morton, Vlastimil Babka, Linus Torvalds
From: David Rientjes <rientjes@google.com> commit da1c67a76f7cf2b3404823d24f9f10fa91aa5dc5 upstream. The conditions that control the isolation mode in isolate_migratepages_range() do not change during the iteration, so extract them out and only define the value once. This actually does have an effect, gcc doesn't optimize it itself because of cc->sync. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <redacted> Acked-by: Vlastimil Babka <redacted> Cc: Joonsoo Kim <redacted> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> --- mm/compaction.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-)
diff --git a/mm/compaction.c b/mm/compaction.c
index 10f9f8c..4530818 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c@@ -461,12 +461,13 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, unsigned long last_pageblock_nr = 0, pageblock_nr; unsigned long nr_scanned = 0, nr_isolated = 0; struct list_head *migratelist = &cc->migratepages; - isolate_mode_t mode = 0; struct lruvec *lruvec; unsigned long flags; bool locked = false; struct page *page = NULL, *valid_page = NULL; bool skipped_async_unsuitable = false; + const isolate_mode_t mode = (!cc->sync ? ISOLATE_ASYNC_MIGRATE : 0) | + (unevictable ? ISOLATE_UNEVICTABLE : 0); /* * Ensure that there are not too many pages isolated from the LRU
@@ -606,12 +607,6 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, continue; } - if (!cc->sync) - mode |= ISOLATE_ASYNC_MIGRATE; - - if (unevictable) - mode |= ISOLATE_UNEVICTABLE; - lruvec = mem_cgroup_page_lruvec(page, zone); /* Try isolate the page */
--
1.8.4.5