From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 7 Oct 2008 19:04:36 +0900 From: KAMEZAWA Hiroyuki Subject: [PATCH 2/6] memcg: make page->mapping NULL before uncharge Message-Id: <20081007190436.febf9c97.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20081007190121.d96e58a6.kamezawa.hiroyu@jp.fujitsu.com> References: <20081007190121.d96e58a6.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "balbir@linux.vnet.ibm.com" , "nishimura@mxp.nes.nec.co.jp" , "akpm@linux-foundation.org" List-ID: 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 BUG_ON() to mem_cgroup_uncharge_cache_page(); Signed-off-by: KAMEZAWA Hiroyuki Reviewed-by: Daisuke Nishimura mm/filemap.c | 2 +- mm/memcontrol.c | 1 + mm/migrate.c | 9 +++++++-- 3 files changed, 9 insertions(+), 3 deletions(-) Index: mmotm-2.6.27-rc7+/mm/filemap.c =================================================================== --- mmotm-2.6.27-rc7+.orig/mm/filemap.c +++ mmotm-2.6.27-rc7+/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: mmotm-2.6.27-rc7+/mm/memcontrol.c =================================================================== --- mmotm-2.6.27-rc7+.orig/mm/memcontrol.c +++ mmotm-2.6.27-rc7+/mm/memcontrol.c @@ -734,6 +734,7 @@ 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: mmotm-2.6.27-rc7+/mm/migrate.c =================================================================== --- mmotm-2.6.27-rc7+.orig/mm/migrate.c +++ mmotm-2.6.27-rc7+/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; } @@ -341,6 +339,8 @@ static int migrate_page_move_mapping(str */ static void migrate_page_copy(struct page *newpage, struct page *page) { + int anon; + copy_highpage(newpage, page); if (PageError(page)) @@ -378,8 +378,13 @@ static void migrate_page_copy(struct pag #endif ClearPagePrivate(page); set_page_private(page, 0); + /* page->mapping contains a flag for PageAnon() */ + anon = PageAnon(page); page->mapping = NULL; + if (!anon) /* This page was removed from radix-tree. */ + mem_cgroup_uncharge_cache_page(page); + /* * If any waiters have accumulated on the new page then * wake them up. -- 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