From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qa0-f45.google.com (mail-qa0-f45.google.com [209.85.216.45]) by kanga.kvack.org (Postfix) with ESMTP id D6E326B0037 for ; Mon, 12 May 2014 09:57:24 -0400 (EDT) Received: by mail-qa0-f45.google.com with SMTP id hw13so7115464qab.32 for ; Mon, 12 May 2014 06:57:24 -0700 (PDT) Received: from qmta14.emeryville.ca.mail.comcast.net (qmta14.emeryville.ca.mail.comcast.net. [2001:558:fe2d:44:76:96:27:212]) by mx.google.com with ESMTP id c4si6009169qad.26.2014.05.12.06.57.23 for ; Mon, 12 May 2014 06:57:24 -0700 (PDT) Date: Mon, 12 May 2014 08:57:20 -0500 (CDT) From: Christoph Lameter Subject: Re: [PATCH] mm: use a irq-safe __mod_zone_page_state in mlocked_vma_newpage() In-Reply-To: <1399652208-18987-1-git-send-email-nasa4836@gmail.com> Message-ID: References: <1399652208-18987-1-git-send-email-nasa4836@gmail.com> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Jianyu Zhan Cc: akpm@linux-foundation.org, mhocko@suse.cz, hannes@cmpxchg.org, riel@redhat.com, minchan@kernel.org, zhangyanfei@cn.fujitsu.com, hanpt@linux.vnet.ibm.com, sasha.levin@oracle.com, oleg@redhat.com, fabf@skynet.be, mgorman@suse.de, aarcange@redhat.com, cldu@marvell.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Sat, 10 May 2014, Jianyu Zhan wrote: > mlocked_vma_newpage() is only called in fault path by > page_add_new_anon_rmap(), which is called on a *new* page. > And such page is initially only visible via the pagetables, and the > pte is locked while calling page_add_new_anon_rmap(), so we need not > use an irq-safe mod_zone_page_state() here, using a light-weight version > __mod_zone_page_state() would be OK. This has nothing to do with the safety of statistics operations that work on different data structures. Which leads to the conclusion that __mod_page_state cannot be used here. -- 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