Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756730Ab0DODJO (ORCPT ); Wed, 14 Apr 2010 23:09:14 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:42817 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756537Ab0DODJM (ORCPT ); Wed, 14 Apr 2010 23:09:12 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Thu, 15 Apr 2010 12:05:16 +0900 From: KAMEZAWA Hiroyuki To: Daisuke Nishimura Cc: LKML , linux-mm , Mel Gorman , Rik van Riel , Minchan Kim , Balbir Singh , KOSAKI Motohiro , Christoph Lameter , Andrea Arcangeli , Andrew Morton Subject: [RFC][BUGFIX][PATCH 1/2] memcg: fix charge bypass route of migration Message-Id: <20100415120516.3891ce46.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20100413134207.f12cdc9c.nishimura@mxp.nes.nec.co.jp> References: <20100413134207.f12cdc9c.nishimura@mxp.nes.nec.co.jp> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 3.0.2 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2104 Lines: 68 I'd like to wait until next mmotm comes out. (So, [RFC]) I'll rebase This patch is based on mmotm-2010/04/05 + mm-migration-take-a-reference-to-the-anon_vma-before-migrating.patch mm-migration-do-not-try-to-migrate-unmapped-anonymous-pages.patch mm-share-the-anon_vma-ref-counts-between-ksm-and-page-migration.patch mm-migration-allow-the-migration-of-pageswapcache-pages.patch memcg-fix-prepare-migration.patch == From: KAMEZAWA Hiroyuki This is an additonal fix to memcg-fix-prepare-migration.patch Now, try_charge can bypass charge if TIF_MEMDIE at el are marked on the caller. In this case, the charge is bypassed. This makes accounts corrupted. (PageCgroup will be marked as PCG_USED even if bypassed, and css->refcnt can leak.) This patch clears passed "*memcg" in bypass route. Because usual page allocater passes memcg=NULL, this patch only affects some special case as - move account - migration - swapin. Signed-off-by: KAMEZAWA Hiroyuki --- mm/memcontrol.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) Index: mmotm-temp/mm/memcontrol.c =================================================================== --- mmotm-temp.orig/mm/memcontrol.c +++ mmotm-temp/mm/memcontrol.c @@ -1606,8 +1606,12 @@ static int __mem_cgroup_try_charge(struc * MEMDIE process. */ if (unlikely(test_thread_flag(TIF_MEMDIE) - || fatal_signal_pending(current))) + || fatal_signal_pending(current))) { + /* Showing we skipped charge */ + if (memcg) + *memcg = NULL; goto bypass; + } /* * We always charge the cgroup the mm_struct belongs to. @@ -2523,7 +2527,6 @@ int mem_cgroup_prepare_migration(struct ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, ptr, false); css_put(&mem->css); } - *ptr = mem; return ret; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/