From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx134.postini.com [74.125.245.134]) by kanga.kvack.org (Postfix) with SMTP id A62DB6B00B6 for ; Tue, 13 Nov 2012 12:15:50 -0500 (EST) Received: by mail-ee0-f41.google.com with SMTP id d41so65876eek.14 for ; Tue, 13 Nov 2012 09:15:50 -0800 (PST) From: Ingo Molnar Subject: [PATCH 31/31] mm: Allow the migration of shared pages Date: Tue, 13 Nov 2012 18:13:54 +0100 Message-Id: <1352826834-11774-32-git-send-email-mingo@kernel.org> In-Reply-To: <1352826834-11774-1-git-send-email-mingo@kernel.org> References: <1352826834-11774-1-git-send-email-mingo@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Paul Turner , Lee Schermerhorn , Christoph Lameter , Rik van Riel , Mel Gorman , Andrew Morton , Andrea Arcangeli , Linus Torvalds , Peter Zijlstra , Thomas Gleixner 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 Cc: Linus Torvalds Cc: Andrew Morton Cc: Andrea Arcangeli Cc: Rik van Riel Cc: Mel Gorman Signed-off-by: Ingo Molnar --- 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org