From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Pekka Enberg" Subject: Re: No, really, stop trying to delete slab until you've finished making slub perform as well Date: Mon, 4 Aug 2008 20:20:08 +0300 Message-ID: <84144f020808041020l7d20f20fs6e090e01c00d28f0@mail.gmail.com> References: <20080801182324.572058187@lameter.com> <20080803015847.GD26461@parisc-linux.org> <48970779.80902@linux-foundation.org> <2f11576a0808040947r69076eecv9ff92ecf583f7af2@mail.gmail.com> <489738CF.7090401@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "KOSAKI Motohiro" , "Matthew Wilcox" , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, "Mel Gorman" , andi@firstfloor.org, "Rik van Riel" , kosaki.motohiro@jp.fujitsu.com To: "Christoph Lameter" Return-path: Received: from py-out-1112.google.com ([64.233.166.179]:28874 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754116AbYHDRUK (ORCPT ); Mon, 4 Aug 2008 13:20:10 -0400 Received: by py-out-1112.google.com with SMTP id p76so1111822pyb.10 for ; Mon, 04 Aug 2008 10:20:09 -0700 (PDT) In-Reply-To: <489738CF.7090401@linux-foundation.org> Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Mon, Aug 4, 2008 at 8:13 PM, Christoph Lameter wrote: > KOSAKI Motohiro wrote: > >> When hackbench running, SLUB consume memory very largely than SLAB. >> then, SLAB often outperform SLUB in memory stavation state. >> >> I don't know why memory comsumption different. >> Anyone know it? > > Can you quantify the difference? > > SLAB buffers objects in its queues. SLUB does rely more on the page allocator. > So SLAB may have its own reserves to fall back on. Also, what kind of machine are we talking about here? If there are a lot of CPUs, SLUB will allocate higher order pages more aggressively than SLAB by default.