From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760753AbZEHOXS (ORCPT ); Fri, 8 May 2009 10:23:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754029AbZEHOXD (ORCPT ); Fri, 8 May 2009 10:23:03 -0400 Received: from courier.cs.helsinki.fi ([128.214.9.1]:50775 "EHLO mail.cs.helsinki.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752385AbZEHOXB (ORCPT ); Fri, 8 May 2009 10:23:01 -0400 Subject: Re: [RFC/PATCH v2] mm: Introduce GFP_PANIC for non-failing allocations From: Pekka Enberg To: Christoph Lameter Cc: Cyrill Gorcunov , Andrew Morton , mingo@elte.hu, mel@csn.ul.ie, linux-kernel@vger.kernel.org, riel@redhat.com, rientjes@google.com, xemul@openvz.org In-Reply-To: References: <20090504122740.GH4173@lenovo> <20090504131311.GA23330@elte.hu> <20090504131638.GJ4173@lenovo> <20090504115335.9bc08587.akpm@linux-foundation.org> <20090504192117.GB31176@lenovo> <20090504123453.d130a6cf.akpm@linux-foundation.org> <20090504200925.GD31176@lenovo> <1241787448.28600.26.camel@penberg-laptop> Date: Fri, 08 May 2009 17:23:00 +0300 Message-Id: <1241792580.28600.41.camel@penberg-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 7bit X-Mailer: Evolution 2.24.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 8 May 2009, Pekka Enberg wrote: > > +#define GFP_PANIC (__GFP_NOFAIL | __GFP_NORETRY | __GFP_NOMEMALLOC) On Fri, 2009-05-08 at 10:20 -0400, Christoph Lameter wrote: > So this means not retrying the allocation a couple of times? Not delving > into reserve pools? Such behavior is good for a allocation that causes a > panic if it fails? If you do GFP_KERNEL|GFP_PANIC, we will cond_resched() and retry if we made some progress. So yes, I think the behavior is good for early-boot call-sites that can't really fail anyway. Pekka