From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta12.messagelabs.com (mail6.bemta12.messagelabs.com [216.82.250.247]) by kanga.kvack.org (Postfix) with ESMTP id 8BD066B004D for ; Tue, 29 Nov 2011 18:43:55 -0500 (EST) Received: from m3.gw.fujitsu.co.jp (unknown [10.0.50.73]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id BA4343EE0AE for ; Wed, 30 Nov 2011 08:43:51 +0900 (JST) Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 9F69845DEB4 for ; Wed, 30 Nov 2011 08:43:51 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 8492745DEAD for ; Wed, 30 Nov 2011 08:43:51 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 768C71DB803F for ; Wed, 30 Nov 2011 08:43:51 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.240.81.146]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 3E3E91DB803B for ; Wed, 30 Nov 2011 08:43:51 +0900 (JST) Date: Wed, 30 Nov 2011 08:42:11 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [patch 5/7] mm: page_cgroup: check page_cgroup arrays in lookup_page_cgroup() only when necessary Message-Id: <20111130084211.15fdefbf.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <1322563925-1667-6-git-send-email-hannes@cmpxchg.org> References: <1322563925-1667-1-git-send-email-hannes@cmpxchg.org> <1322563925-1667-6-git-send-email-hannes@cmpxchg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Andrew Morton , Michal Hocko , Balbir Singh , David Rientjes , Hugh Dickins , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Tue, 29 Nov 2011 11:52:03 +0100 Johannes Weiner wrote: > lookup_page_cgroup() is usually used only against pages that are used > in userspace. > > The exception is the CONFIG_DEBUG_VM-only memcg check from the page > allocator: it can run on pages without page_cgroup descriptors > allocated when the pages are fed into the page allocator for the first > time during boot or memory hotplug. > > Include the array check only when CONFIG_DEBUG_VM is set and save the > unnecessary check in production kernels. > > Signed-off-by: Johannes Weiner Acked-by: KAMEZAWA Hiroyuki -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org