Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751709AbWBWKKt (ORCPT ); Thu, 23 Feb 2006 05:10:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751710AbWBWKKt (ORCPT ); Thu, 23 Feb 2006 05:10:49 -0500 Received: from smtp.osdl.org ([65.172.181.4]:27587 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751706AbWBWKKr (ORCPT ); Thu, 23 Feb 2006 05:10:47 -0500 Date: Thu, 23 Feb 2006 02:09:57 -0800 From: Andrew Morton To: Alok Kataria Cc: penberg@cs.helsinki.fi, clameter@engr.sgi.com, manfred@colorfullife.com, linux-kernel@vger.kernel.org Subject: Re: slab: Remove SLAB_NO_REAP option Message-Id: <20060223020957.478d4cc1.akpm@osdl.org> In-Reply-To: References: X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1476 Lines: 35 Alok Kataria wrote: > > On Thu, 2006-02-23 at 14:18, Pekka Enberg wrote: > On 2/23/06, Alok Kataria wrote: > > > There can be some caches which are not used quite often, kmem_cache > > > for instance. Now from performance perspective having SLAB_NO_REAP for > > > such caches is good. > > > > Yeah, kmem_cache sounds like a realistic user, but I am wondering if > > it makes any sense for anyone else to use it? > > > Right, thats why my question still is why do these iscsi & ocfs cache > have this flag set. I'm sure there's no good reason. > If we are sure that the flag is still required, we can use the patch > below. I'm very much hoping that it is not needed. Would prefer to just toss the whole thing away. What's it supposed to do anyway? Keep wholly-unused pages hanging about in each slab cache? If so, it may well be a net loss - it'd be better to push those pages back into the page allocator so they can get reused for something else while they're possibly still in-cache. Similarly, it's better to fall back to the page allocator for a new slab page because that's more likely to give us a cache-hot one. I'm convinced, anyway ;) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/