Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753273AbZKATcw (ORCPT ); Sun, 1 Nov 2009 14:32:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752224AbZKATcu (ORCPT ); Sun, 1 Nov 2009 14:32:50 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:58250 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751059AbZKATct (ORCPT ); Sun, 1 Nov 2009 14:32:49 -0500 Date: Sun, 1 Nov 2009 20:32:47 +0100 From: Pavel Machek To: Rik van Riel Cc: David Rientjes , Andrew Morton , Mel Gorman , stable@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Frans Pop , Jiri Kosina , Sven Geggus , Karol Lewandowski , Tobias Oetiker , KOSAKI Motohiro , Pekka Enberg , Christoph Lameter , Stephan von Krawczynski , kernel-testers@vger.kernel.org Subject: Re: [PATCH 2/3] page allocator: Do not allow interrupts to use ALLOC_HARDER Message-ID: <20091101193247.GA2155@elf.ucw.cz> References: <20091027130924.fa903f5a.akpm@linux-foundation.org> <20091031184054.GB1475@ucw.cz> <20091031201158.GB29536@elf.ucw.cz> <20091031222905.GA32720@elf.ucw.cz> <4AECC04B.9060808@redhat.com> <20091101073527.GB32720@elf.ucw.cz> <4AED9EB4.5080601@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4AED9EB4.5080601@redhat.com> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1386 Lines: 36 On Sun 2009-11-01 09:44:04, Rik van Riel wrote: > On 11/01/2009 02:35 AM, Pavel Machek wrote: > >>>I believe it would be better to simply remove it. > >> > >>You are against trying to give the realtime tasks a best effort > >>advantage at memory allocation? > > > >Yes. Those memory reserves were for kernel, GPF_ATOMIC and stuff. Now > >realtime tasks are allowed to eat into them. That feels wrong. > > > >"realtime" tasks are not automatically "more important". > > > >>Realtime apps often *have* to allocate memory on the kernel side, > >>because they use network system calls, etc... > > > >So what? As soon as they do that, they lose any guarantees, anyway. > > They might lose the absolute guarantee, but that's no reason > not to give it our best effort! You know, there's no reason not to give best effort to normal tasks, too... Well, OTOH that means that realtime tasks can now interfere with interrupt memory allocations... Anyway, I guess this is not terribly important... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/