From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Piggin Subject: Re: [15/17] SLUB: Support virtual fallback via SLAB_VFALLBACK Date: Tue, 2 Oct 2007 18:37:24 +1000 Message-ID: <200710021837.24772.nickpiggin@yahoo.com.au> References: <20070919033605.785839297@sgi.com> <1191055513.18147.97.camel@lappy> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: Peter Zijlstra , Christoph Hellwig , Mel Gorman , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, David Chinner , Jens Axboe , akpm@linux-foundation.org To: Christoph Lameter Return-path: Received: from smtp106.mail.mud.yahoo.com ([209.191.85.216]:49056 "HELO smtp106.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753295AbXJCBJC (ORCPT ); Tue, 2 Oct 2007 21:09:02 -0400 In-Reply-To: Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Tuesday 02 October 2007 07:01, Christoph Lameter wrote: > On Sat, 29 Sep 2007, Peter Zijlstra wrote: > > On Fri, 2007-09-28 at 11:20 -0700, Christoph Lameter wrote: > > > Really? That means we can no longer even allocate stacks for forking. > > > > I think I'm running with 4k stacks... > > 4k stacks will never fly on an SGI x86_64 NUMA configuration given the > additional data that may be kept on the stack. We are currently > considering to go from 8k to 16k (or even 32k) to make things work. So > having the ability to put the stacks in vmalloc space may be something to > look at. i386 and x86-64 already used 8K stacks for years and they have never really been much problem before. They only started failing when contiguous memory is getting used up by other things, _even with_ those anti-frag patches in there. Bottom line is that you do not use higher order allocations when you do not need them.