From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161336AbWHJPZo (ORCPT ); Thu, 10 Aug 2006 11:25:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161338AbWHJPZn (ORCPT ); Thu, 10 Aug 2006 11:25:43 -0400 Received: from omx2-ext.sgi.com ([192.48.171.19]:12260 "EHLO omx2.sgi.com") by vger.kernel.org with ESMTP id S1161336AbWHJPZn (ORCPT ); Thu, 10 Aug 2006 11:25:43 -0400 Date: Thu, 10 Aug 2006 08:25:17 -0700 (PDT) From: Christoph Lameter To: KAMEZAWA Hiroyuki cc: mpm@selenic.com, npiggin@suse.de, manfred@colorfullife.com, linux-kernel@vger.kernel.org Subject: Re: [RFC] Simple Slab: A slab allocator with minimal meta information In-Reply-To: <20060810151305.bc4602e0.kamezawa.hiroyu@jp.fujitsu.com> Message-ID: References: <20060810140153.e5932e76.kamezawa.hiroyu@jp.fujitsu.com> <20060810144451.13591e4b.kamezawa.hiroyu@jp.fujitsu.com> <20060810151305.bc4602e0.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 10 Aug 2006, KAMEZAWA Hiroyuki wrote: > BTW, in recent Linux, many objects are freed by call_rcu(hoo, dealyed_free_foo). > Objects are freed far after it was touched. > I think catching this kind of freeing will not boost performance by cache-hit if > reuse freed page (object). Yes that is a general problem with RCU freeing. One can use the SLAB_DESTROY_BY_RCU option to have RCU applied to the whole slab. In that case on can use the cache hot effect but has the additional problem in RCU of dealing with the issue that the object can be replaced at any time.