There's no good reason to disallow the migration of pages shared by multiple processes - the migration code itself is already properly walking the rmap chain.
So allow it. We've tested this with various workloads and no ill effect appears to have come from this. Cc: Peter Zijlstra <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Mel Gorman <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> --- mm/migrate.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 72d1056..b89062d 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1427,12 +1427,6 @@ int migrate_misplaced_page(struct page *page, int node) gfp_t gfp = GFP_HIGHUSER_MOVABLE; /* - * Don't migrate pages that are mapped in multiple processes. - */ - if (page_mapcount(page) != 1) - goto out; - - /* * Never wait for allocations just to migrate on fault, but don't dip * into reserves. And, only accept pages from the specified node. No * sense migrating to a different "misplaced" page! -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
