Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757944AbXKCS1G (ORCPT ); Sat, 3 Nov 2007 14:27:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755174AbXKCS04 (ORCPT ); Sat, 3 Nov 2007 14:26:56 -0400 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:48849 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754867AbXKCS0z (ORCPT ); Sat, 3 Nov 2007 14:26:55 -0400 Date: Sat, 3 Nov 2007 11:26:55 -0700 (PDT) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Hugh Dickins cc: Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] slub: fix Objects count In-Reply-To: Message-ID: References: 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 Content-Length: 783 Lines: 19 On Sat, 3 Nov 2007, Hugh Dickins wrote: > The count of active Objects shown by Slub's slabinfo is too approximate, > because each cpu slab is counted as all in use, even when lots are free. > That makes tracing leaks harder than it need be. True but that is the way it is for performance reasons. > Add a free count into kmem_cache_cpu (which doesn't enlarge it on 64-bit), > to keep that count in the hot and dirty per-cpu cacheline. Adds to much overhead to the fast paths and will make the current optimizations in mm impossible. - 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/