On Fri, Nov 18, 2011 at 04:58:40PM +0000, Mel Gorman wrote: > Commit [39deaf85: mm: compaction: make isolate_lru_page() filter-aware] > noted that compaction does not migrate dirty or writeback pages and > that is was meaningless to pick the page and re-add it to the LRU list. > > What was missed during review is that asynchronous migration moves > dirty pages if their ->migratepage callback is migrate_page() because > these can be moved without blocking. This potentially impacted > hugepage allocation success rates by a factor depending on how many > dirty pages are in the system. > > This patch partially reverts 39deaf85 to allow migration to isolate > dirty pages again. This increases how much compaction disrupts the > LRU but that is addressed later in the series. > > Signed-off-by: Mel Gorman <mgorman@xxxxxxx> > --- > mm/compaction.c | 3 --- > 1 files changed, 0 insertions(+), 3 deletions(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index 899d956..237560e 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -349,9 +349,6 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, > continue; > } > > - if (!cc->sync) > - mode |= ISOLATE_CLEAN; > - > /* Try isolate the page */ > if (__isolate_lru_page(page, mode, 0) != 0) > continue; Reviewed-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>