Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757460AbZFLNyX (ORCPT ); Fri, 12 Jun 2009 09:54:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756000AbZFLNyN (ORCPT ); Fri, 12 Jun 2009 09:54:13 -0400 Received: from courier.cs.helsinki.fi ([128.214.9.1]:42180 "EHLO mail.cs.helsinki.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754835AbZFLNyL (ORCPT ); Fri, 12 Jun 2009 09:54:11 -0400 Subject: Re: slab: setup allocators earlier in the boot sequence From: Pekka Enberg To: Christoph Lameter Cc: Benjamin Herrenschmidt , Linus Torvalds , Linux Kernel list , linux-mm , mingo@elte.hu, akpm@linux-foundation.org, npiggin@suse.de In-Reply-To: References: <200906111959.n5BJxFj9021205@hera.kernel.org> <1244770230.7172.4.camel@pasglop> <1244779009.7172.52.camel@pasglop> <1244780756.7172.58.camel@pasglop> <1244783235.7172.61.camel@pasglop> <1244792079.7172.74.camel@pasglop> <1244792745.30512.13.camel@penberg-laptop> <1244796045.7172.82.camel@pasglop> <1244796211.30512.32.camel@penberg-laptop> <1244796837.7172.95.camel@pasglop> <1244797659.30512.37.camel@penberg-laptop> Date: Fri, 12 Jun 2009 16:54:12 +0300 Message-Id: <1244814852.30512.67.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 Content-Length: 1007 Lines: 24 Hi Christoph, On Fri, 2009-06-12 at 09:49 -0400, Christoph Lameter wrote: > Best thing to do is to recognize the fact that we are still in early boot > in the allocators. Derived allocators (such as slab and vmalloc) mask bits > using GFP_RECLAIM_MASK and when doing allocations through the page > allocator. You could make GFP_RECLAIM_MASK a variable. During boot > __GFP_WAIT would not be set in GFP_RECLAIM_MASK. Ben's patch does something like that and I have patches that do that floating around too. The problem here is that it's not enough that we make GFP_RECLAIM_MASK a variable. There are various _debugging checks_ that happen much earlier than that. We need to mask out those too which adds overhead to kmalloc() fastpath, for example. Pekka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/