From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751360AbWDFDl3 (ORCPT ); Wed, 5 Apr 2006 23:41:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751361AbWDFDl3 (ORCPT ); Wed, 5 Apr 2006 23:41:29 -0400 Received: from smtp.osdl.org ([65.172.181.4]:52362 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751360AbWDFDl2 (ORCPT ); Wed, 5 Apr 2006 23:41:28 -0400 Date: Wed, 5 Apr 2006 20:40:09 -0700 From: Andrew Morton To: Con Kolivas Cc: ck@vds.kolivas.org, nickpiggin@yahoo.com.au, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: Respin: [PATCH] mm: limit lowmem_reserve Message-Id: <20060405204009.3235b021.akpm@osdl.org> In-Reply-To: <200604061258.40487.kernel@kolivas.org> References: <200604021401.13331.kernel@kolivas.org> <20060405194344.1915b57a.akpm@osdl.org> <200604061255.55055.kernel@kolivas.org> <200604061258.40487.kernel@kolivas.org> 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 Con Kolivas wrote: > > On Thursday 06 April 2006 12:55, Con Kolivas wrote: > > On Thursday 06 April 2006 12:43, Andrew Morton wrote: > > > Con Kolivas wrote: > > > > It is possible with a low enough lowmem_reserve ratio to make > > > > zone_watermark_ok fail repeatedly if the lower_zone is small enough. > > > > > > Is that actually a problem? > > > > Every single call to get_page_from_freelist will call on zone reclaim. It > > seems a problem to me if every call to __alloc_pages will do that? > > every call to __alloc_pages of that zone I mean > One would need to check with the NUMA guys. zone_reclaim() has a (lame-looking) timer in there to prevent it from doing too much work. That, or I'm missing something. This problem wasn't particularly well described, sorry.