From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760578AbXEQRxb (ORCPT ); Thu, 17 May 2007 13:53:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759078AbXEQRxS (ORCPT ); Thu, 17 May 2007 13:53:18 -0400 Received: from viefep13-int.chello.at ([213.46.255.15]:51651 "EHLO viefep11-int.chello.at" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758761AbXEQRxR (ORCPT ); Thu, 17 May 2007 13:53:17 -0400 Subject: Re: [PATCH 0/5] make slab gfp fair From: Peter Zijlstra To: Christoph Lameter Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Thomas Graf , David Miller , Andrew Morton , Daniel Phillips , Pekka Enberg , Matt Mackall In-Reply-To: References: <20070514131904.440041502@chello.nl> <1179385718.27354.17.camel@twins> Content-Type: text/plain Date: Thu, 17 May 2007 19:52:15 +0200 Message-Id: <1179424335.2925.5.camel@lappy> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2007-05-17 at 10:29 -0700, Christoph Lameter wrote: > On Thu, 17 May 2007, Peter Zijlstra wrote: > > > I'm really not seeing why you're making such a fuzz about it; normally > > when you push the system this hard we're failing allocations left right > > and center too. Its just that the block IO path has some mempools which > > allow it to write out some (swap) pages and slowly get back to sanity. > > I am weirdly confused by these patches. Among other things you told me > that the performance does not matter since its never (or rarely) being > used (why do it then?). When we are very low on memory and do access the reserves by means of ALLOC_NO_WATERMARKS, we want to avoid processed that are not entitled to use such memory from running away with the little we have. That is the whole and only point; restrict memory allocated under ALLOC_NO_WATERMARKS to those processes that are entitled to it.