Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755841AbYHTKAy (ORCPT ); Wed, 20 Aug 2008 06:00:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753798AbYHTKAj (ORCPT ); Wed, 20 Aug 2008 06:00:39 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:37250 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753513AbYHTKAi (ORCPT ); Wed, 20 Aug 2008 06:00:38 -0400 Date: Wed, 20 Aug 2008 19:07:02 +0900 From: KAMEZAWA Hiroyuki To: KAMEZAWA Hiroyuki Cc: LKML , "balbir@linux.vnet.ibm.com" , "yamamoto@valinux.co.jp" , "nishimura@mxp.nes.nec.co.jp" , ryov@valinux.co.jp, "linux-mm@kvack.org" Subject: [RFC][PATCH -mm 6/7] memcg: make-mapping-null-before-calling-uncharge.patch Message-Id: <20080820190702.616f4260.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20080820185306.e897c512.kamezawa.hiroyu@jp.fujitsu.com> References: <20080819173014.17358c17.kamezawa.hiroyu@jp.fujitsu.com> <20080820185306.e897c512.kamezawa.hiroyu@jp.fujitsu.com> Organization: Fujitsu X-Mailer: Sylpheed 2.4.2 (GTK+ 2.10.11; 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: 2698 Lines: 82 This patch tries to make page->mapping to be NULL before mem_cgroup_uncharge_cache_page() is called. "page->mapping == NULL" is a good check for "whether the page is still radix-tree or not". This patch also adds VM_BUG_ON() to mem_cgroup_uncharge_cache_page(); Signed-off-by: KAMEZAWA Hiroyuki --- mm/filemap.c | 2 +- mm/memcontrol.c | 1 + mm/migrate.c | 11 +++++++++-- 3 files changed, 11 insertions(+), 3 deletions(-) Index: mmtom-2.6.27-rc3+/mm/filemap.c =================================================================== --- mmtom-2.6.27-rc3+.orig/mm/filemap.c +++ mmtom-2.6.27-rc3+/mm/filemap.c @@ -116,12 +116,12 @@ void __remove_from_page_cache(struct pag { struct address_space *mapping = page->mapping; - mem_cgroup_uncharge_cache_page(page); radix_tree_delete(&mapping->page_tree, page->index); page->mapping = NULL; mapping->nrpages--; __dec_zone_page_state(page, NR_FILE_PAGES); BUG_ON(page_mapped(page)); + mem_cgroup_uncharge_cache_page(page); /* * Some filesystems seem to re-dirty the page even after Index: mmtom-2.6.27-rc3+/mm/memcontrol.c =================================================================== --- mmtom-2.6.27-rc3+.orig/mm/memcontrol.c +++ mmtom-2.6.27-rc3+/mm/memcontrol.c @@ -854,6 +854,7 @@ void mem_cgroup_uncharge_page(struct pag void mem_cgroup_uncharge_cache_page(struct page *page) { VM_BUG_ON(page_mapped(page)); + VM_BUG_ON(page->mapping); __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE); } Index: mmtom-2.6.27-rc3+/mm/migrate.c =================================================================== --- mmtom-2.6.27-rc3+.orig/mm/migrate.c +++ mmtom-2.6.27-rc3+/mm/migrate.c @@ -330,8 +330,6 @@ static int migrate_page_move_mapping(str __inc_zone_page_state(newpage, NR_FILE_PAGES); spin_unlock_irq(&mapping->tree_lock); - if (!PageSwapCache(newpage)) - mem_cgroup_uncharge_cache_page(page); return 0; } @@ -379,6 +377,15 @@ static void migrate_page_copy(struct pag ClearPagePrivate(page); set_page_private(page, 0); page->mapping = NULL; + /* page->mapping contains a flag for PageAnon() */ + if (PageAnon(page)) { + /* This page is uncharged at try_to_unmap(). */ + page->mapping = NULL; + } else { + /* Obsolete file cache should be uncharged */ + page->mapping = NULL; + mem_cgroup_uncharge_cache_page(page); + } /* * If any waiters have accumulated on the new page then -- 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/