From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Lameter Subject: Re: [15/17] SLUB: Support virtual fallback via SLAB_VFALLBACK Date: Mon, 1 Oct 2007 13:50:44 -0700 (PDT) Message-ID: References: <20070919033605.785839297@sgi.com> <200709280742.38262.nickpiggin@yahoo.com.au> <200709281514.48293.nickpiggin@yahoo.com.au> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Christoph Hellwig , Mel Gorman , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, David Chinner , Jens Axboe To: Nick Piggin Return-path: Received: from netops-testserver-4-out.sgi.com ([192.48.171.29]:42521 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752243AbXJAUup (ORCPT ); Mon, 1 Oct 2007 16:50:45 -0400 In-Reply-To: <200709281514.48293.nickpiggin@yahoo.com.au> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Fri, 28 Sep 2007, Nick Piggin wrote: > I thought it was slower. Have you fixed the performance regression? > (OK, I read further down that you are still working on it but not confirmed > yet...) The problem is with the weird way of Intel testing and communication. Every 3-6 month or so they will tell you the system is X% up or down on arch Y (and they wont give you details because its somehow secret). And then there are conflicting statements by the two or so performance test departments. One of them repeatedly assured me that they do not see any regressions. > OK, so long as it isn't going to depend on using higher order pages, that's > fine. (if they help even further as an optional thing, that's fine too. You > can turn them on your huge systems and not even bother about adding > this vmap fallback -- you won't have me to nag you about these > purely theoretical issues). Well the vmap fallback is generally useful AFAICT. Higher order allocations are common on some of our platforms. Order 1 failures even affect essential things like stacks that have nothing to do with SLUB and the LBS patchset.