From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759572AbZF3WDf (ORCPT ); Tue, 30 Jun 2009 18:03:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752271AbZF3WD2 (ORCPT ); Tue, 30 Jun 2009 18:03:28 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:42856 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752569AbZF3WD1 (ORCPT ); Tue, 30 Jun 2009 18:03:27 -0400 Date: Wed, 1 Jul 2009 00:03:18 +0200 From: Ingo Molnar To: Jan Beulich Cc: bernhard.walle@gmx.de, Thomas Gleixner , hpa@zytor.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] don't use alloc_bootmem_low() where not strictly needed Message-ID: <20090630220318.GC1241@elte.hu> References: <4A4A111A020000780000831A@vpn.id2.novell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4A4A111A020000780000831A@vpn.id2.novell.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Jan Beulich wrote: > Since alloc_bootmem() will never return inaccessible (via virtual > addressing) memory anyway, using the ..._low() variant only makes > sense when the physical address range of the allocated memory must > fulfill further constraints, espacially since on 64-bits (or more > generally in all cases where the pools the two variants allocate > from are different), the space available for ..._low() is more > easily exhausted than the full available range. hm, i have some vague memories of the _low() being relevant for things like PAGEALLOC stability. Thomas, do you remember anything specific there? Ingo