From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932093AbWDEWDE (ORCPT ); Wed, 5 Apr 2006 18:03:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932096AbWDEWDE (ORCPT ); Wed, 5 Apr 2006 18:03:04 -0400 Received: from smtp-out.google.com ([216.239.45.12]:26411 "EHLO smtp-out.google.com") by vger.kernel.org with ESMTP id S932093AbWDEWDC (ORCPT ); Wed, 5 Apr 2006 18:03:02 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=received:message-id:date:from:user-agent: x-accept-language:mime-version:to:cc:subject:references:in-reply-to: content-type:content-transfer-encoding; b=jgnGiGTDue/iowVINWX8xq75IcKvOXvPxFqeWWStxaRAGfbpc5SMY8TwcHfPul83c vJrrduk6gtQ8lpFzwlilg== Message-ID: <44343E86.30301@google.com> Date: Wed, 05 Apr 2006 15:02:46 -0700 From: Daniel Phillips User-Agent: Mozilla Thunderbird 1.0.7 (X11/20051011) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Jeff Dike CC: Andrew Morton , linux-kernel@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net Subject: Re: [PATCH 12/16] UML - Memory hotplug References: <200603241814.k2OIExNn005555@ccure.user-mode-linux.org> <20060324144535.37b3daf7.akpm@osdl.org> <20060325010524.GA8117@ccure.user-mode-linux.org> In-Reply-To: <20060325010524.GA8117@ccure.user-mode-linux.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jeff Dike wrote: > This is the big question with this patch. How incestuous do I want to > get with the VM system in order to get it to free up pages? For now, > I decided to be fairly hands-off, allocate as many pages as I can get, > and return the total number to the host. The host, if it wasn't happy > with the results, can wait a bit while the UML notices that it is > really low on memory and frees some up, and then hit up the UML for > the remainder. And also wrote: > page = alloc_page(GFP_ATOMIC); A slightly different objection than Andrew's: this will rapidly eat up all the pages available for, e.g., receiving network packets, probably not what you want. How about flags=0? This will dip a little way into reserves but not as far as interrupts or realtime tasks, and will not attempt any reclaim. (Maybe we should have a GFP define for that.) > INIT_LIST_HEAD(&unplugged->list); > list_add(&unplugged->list, &unplugged_pages); You don't need to initialize the list element you are adding. Regards, Daniel