From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751170AbVKMHMf (ORCPT ); Sun, 13 Nov 2005 02:12:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751347AbVKMHMf (ORCPT ); Sun, 13 Nov 2005 02:12:35 -0500 Received: from smtp.osdl.org ([65.172.181.4]:15250 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751170AbVKMHMe (ORCPT ); Sun, 13 Nov 2005 02:12:34 -0500 Date: Sat, 12 Nov 2005 23:12:11 -0800 From: Andrew Morton To: Paul Jackson Cc: pj@sgi.com, nickpiggin@yahoo.com.au, rohit.seth@intel.com, torvalds@osdl.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH]: Cleanup of __alloc_pages Message-Id: <20051112231211.372be3a9.akpm@osdl.org> In-Reply-To: <20051112211429.294b3783.pj@sgi.com> References: <20051107174349.A8018@unix-os.sc.intel.com> <20051107175358.62c484a3.akpm@osdl.org> <1131416195.20471.31.camel@akash.sc.intel.com> <43701FC6.5050104@yahoo.com.au> <20051107214420.6d0f6ec4.pj@sgi.com> <43703EFB.1010103@yahoo.com.au> <1131473876.2400.9.camel@akash.sc.intel.com> <43716476.1030306@yahoo.com.au> <20051112210913.0b365815.pj@sgi.com> <20051112211429.294b3783.pj@sgi.com> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Paul Jackson wrote: > > fs/xfs/linux-2.6/xfs_buf.c has: > aentry = kmalloc(sizeof(a_list_t), GFP_ATOMIC & ~__GFP_HIGH); That's a reasonable thing to do, actually. GFP_ATOMIC means "don't sleep" (!__GFP_WAIT) and "use emergency pools" (__GFP_HIGH). XFS is saying "don't sleep" and "don't use the emergency pools". Yes, the fact that GFP_ATOMIC also implies "use the emergency pool" is unfortunate, and perhaps the two should always have been separated out, at least to make the programmer think about whether the code really needs access to the emergency pools. Usually it does. But I haven't seen much sign that it's causing any problems.