From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754956AbYGYLTV (ORCPT ); Fri, 25 Jul 2008 07:19:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752414AbYGYLTC (ORCPT ); Fri, 25 Jul 2008 07:19:02 -0400 Received: from viefep18-int.chello.at ([213.46.255.22]:52301 "EHLO viefep15-int.chello.at" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751820AbYGYLTA (ORCPT ); Fri, 25 Jul 2008 07:19:00 -0400 X-SourceIP: 62.163.52.83 Subject: Re: [PATCH 30/30] nfs: fix various memory recursions possible with swap over NFS. From: Peter Zijlstra To: KOSAKI Motohiro Cc: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, trond.myklebust@fys.uio.no, Daniel Lezcano , Pekka Enberg , Neil Brown In-Reply-To: <20080725201324.86BE.KOSAKI.MOTOHIRO@jp.fujitsu.com> References: <20080725194517.86BB.KOSAKI.MOTOHIRO@jp.fujitsu.com> <1216983472.7257.365.camel@twins> <20080725201324.86BE.KOSAKI.MOTOHIRO@jp.fujitsu.com> Content-Type: text/plain Date: Fri, 25 Jul 2008 13:19:01 +0200 Message-Id: <1216984741.7257.366.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2008-07-25 at 20:15 +0900, KOSAKI Motohiro wrote: > > On Fri, 2008-07-25 at 19:46 +0900, KOSAKI Motohiro wrote: > > > > GFP_NOFS is not enough, since swap traffic is IO, hence fall back to GFP_NOIO. > > > > > > this comment imply turn on GFP_NOIO, but the code is s/NOFS/NOIO/. why? > > > > Does the misunderstanding stem from the use of 'enough'? > > > > GFP_NOFS is _more_ permissive than GFP_NOIO in that it will initiate IO, > > just not of any filesystem data. > > > > > > The problem is that previuosly NOFS was correct because that avoids > > recursion into the NFS code, it now is not, because also IO (swap) can > > lead to this recursion. > > > Thanks nicer explain. > So, I hope add above 3 line to patch description. Done, thanks! From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from edge01.upc.biz ([192.168.13.236]) by viefep12-int.chello.at (InterMail vM.7.08.02.00 201-2186-121-20061213) with ESMTP id <20080725111854.LCKK29370.viefep12-int.chello.at@edge01.upc.biz> for ; Fri, 25 Jul 2008 13:18:54 +0200 Subject: Re: [PATCH 30/30] nfs: fix various memory recursions possible with swap over NFS. From: Peter Zijlstra In-Reply-To: <20080725201324.86BE.KOSAKI.MOTOHIRO@jp.fujitsu.com> References: <20080725194517.86BB.KOSAKI.MOTOHIRO@jp.fujitsu.com> <1216983472.7257.365.camel@twins> <20080725201324.86BE.KOSAKI.MOTOHIRO@jp.fujitsu.com> Content-Type: text/plain Date: Fri, 25 Jul 2008 13:19:01 +0200 Message-Id: <1216984741.7257.366.camel@twins> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KOSAKI Motohiro Cc: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, trond.myklebust@fys.uio.no, Daniel Lezcano , Pekka Enberg , Neil Brown List-ID: On Fri, 2008-07-25 at 20:15 +0900, KOSAKI Motohiro wrote: > > On Fri, 2008-07-25 at 19:46 +0900, KOSAKI Motohiro wrote: > > > > GFP_NOFS is not enough, since swap traffic is IO, hence fall back to GFP_NOIO. > > > > > > this comment imply turn on GFP_NOIO, but the code is s/NOFS/NOIO/. why? > > > > Does the misunderstanding stem from the use of 'enough'? > > > > GFP_NOFS is _more_ permissive than GFP_NOIO in that it will initiate IO, > > just not of any filesystem data. > > > > > > The problem is that previuosly NOFS was correct because that avoids > > recursion into the NFS code, it now is not, because also IO (swap) can > > lead to this recursion. > > > Thanks nicer explain. > So, I hope add above 3 line to patch description. Done, thanks! -- 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