From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Mackall Subject: Re: [patch 21/21] slab defrag: Obsolete SLAB Date: Wed, 14 May 2008 13:18:32 -0500 Message-ID: <1210789112.4093.14.camel@calx> References: <20080510030831.796641881@sgi.com> <20080510030919.604216074@sgi.com> <4825709A.2020407@firstfloor.org> <20080510221515.3540a6cc@bree.surriel.com> <2f11576a0805120038s334dc56cuaf16b8b7c6f87098@mail.gmail.com> <84144f020805120054t1370236ei5ff52279457e026e@mail.gmail.com> <482B2617.5010605@firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Andi Kleen , Pekka Enberg , KOSAKI Motohiro , Rik van Riel , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Mel Gorman , Matthew Wilcox , "Zhang, Yanmin" To: Christoph Lameter Return-path: Received: from waste.org ([66.93.16.53]:55201 "EHLO waste.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758395AbYENSaj (ORCPT ); Wed, 14 May 2008 14:30:39 -0400 In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed, 2008-05-14 at 11:03 -0700, Christoph Lameter wrote: > > What is the big problem of having a batched free queue? If the expiry > > is done at a good bounded time (e.g. on interrupt exit or similar) > > locally on the CPU it shouldn't be a big issue, should it? > > Interrupt exit in general would have to inspect the per cpu structures of > all slab caches on the system? Why's that? When we're not under pressure (fast path), we can delay (and batch) remote frees. When we are under pressure (slow path), we can do everything immediately. -- Mathematics is the supreme nostalgia of our time.