From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754845Ab1K2Kxd (ORCPT ); Tue, 29 Nov 2011 05:53:33 -0500 Received: from zene.cmpxchg.org ([85.214.230.12]:54508 "EHLO zene.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754746Ab1K2Kwl (ORCPT ); Tue, 29 Nov 2011 05:52:41 -0500 From: Johannes Weiner To: Andrew Morton Cc: KAMEZAWA Hiroyuki , Michal Hocko , Balbir Singh , David Rientjes , Hugh Dickins , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [patch 6/7] mm: memcg: remove unneeded checks from newpage_charge() Date: Tue, 29 Nov 2011 11:52:04 +0100 Message-Id: <1322563925-1667-7-git-send-email-hannes@cmpxchg.org> X-Mailer: git-send-email 1.7.6.4 In-Reply-To: <1322563925-1667-1-git-send-email-hannes@cmpxchg.org> References: <1322563925-1667-1-git-send-email-hannes@cmpxchg.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johannes Weiner All callsites pass in freshly allocated pages and a valid mm. As a result, all checks pertaining the page's mapcount, page->mapping or the fallback to init_mm are unneeded. Signed-off-by: Johannes Weiner Acked-by: KAMEZAWA Hiroyuki Acked-by: Michal Hocko --- mm/memcontrol.c | 16 ++++------------ 1 files changed, 4 insertions(+), 12 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 8ccb342..f5aa1b8 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2679,19 +2679,11 @@ int mem_cgroup_newpage_charge(struct page *page, { if (mem_cgroup_disabled()) return 0; - /* - * If already mapped, we don't have to account. - * If page cache, page->mapping has address_space. - * But page->mapping may have out-of-use anon_vma pointer, - * detecit it by PageAnon() check. newly-mapped-anon's page->mapping - * is NULL. - */ - if (page_mapped(page) || (page->mapping && !PageAnon(page))) - return 0; - if (unlikely(!mm)) - mm = &init_mm; + VM_BUG_ON(page_mapped(page)); + VM_BUG_ON(page->mapping && !PageAnon(page)); + VM_BUG_ON(!mm); return mem_cgroup_charge_common(page, mm, gfp_mask, - MEM_CGROUP_CHARGE_TYPE_MAPPED); + MEM_CGROUP_CHARGE_TYPE_MAPPED); } static void -- 1.7.6.4