Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753720AbZKDBq5 (ORCPT ); Tue, 3 Nov 2009 20:46:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753153AbZKDBq4 (ORCPT ); Tue, 3 Nov 2009 20:46:56 -0500 Received: from smtp-out.google.com ([216.239.45.13]:24637 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751012AbZKDBqz (ORCPT ); Tue, 3 Nov 2009 20:46:55 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id: references:user-agent:mime-version:content-type:x-system-of-record; b=uj+gK2wAt5Yryt/n0AUGBzzFD5E69b2EZPK0HgCKqK3v/VHJDtf+L+nxZQyCxY4id u2/+pWyGJuD6Xd7sX+3zw== Date: Tue, 3 Nov 2009 17:46:48 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Christoph Lameter cc: Rik van Riel , Pavel Machek , 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 , Stephan von Krawczynski , kernel-testers@vger.kernel.org Subject: Re: [PATCH 2/3] page allocator: Do not allow interrupts to use ALLOC_HARDER In-Reply-To: Message-ID: References: <1256650833-15516-1-git-send-email-mel@csn.ul.ie> <1256650833-15516-3-git-send-email-mel@csn.ul.ie> <20091027130924.fa903f5a.akpm@linux-foundation.org> <20091031184054.GB1475@ucw.cz> <20091031201158.GB29536@elf.ucw.cz> <4AECCF6A.4020206@redhat.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1163 Lines: 28 On Tue, 3 Nov 2009, Christoph Lameter wrote: > If you dont know what "realtime" is then we cannot really implement > "realtime" behavior in the page allocator. > It's not intended to implement realtime behavior! This is a convenience given to rt_task() to reduce latency when possible by avoiding direct reclaim and allowing background reclaim to bring us back over the low watermark. That's been in the page allocator for over four years and is not intended to implement realtime behavior. These tasks do not rely on memory reserves being available. Is it really hard to believe that tasks with such high priorities are given an exemption in the page allocator so that we reclaim in the background instead of directly? I hope we can move this to another thread if people would like to remove this exemption completely instead of talking about this trivial fix, which I doubt there's any objection to. -- 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/