Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754065Ab3HVQwl (ORCPT ); Thu, 22 Aug 2013 12:52:41 -0400 Received: from a9-58.smtp-out.amazonses.com ([54.240.9.58]:52534 "EHLO a9-58.smtp-out.amazonses.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753787Ab3HVQwk (ORCPT ); Thu, 22 Aug 2013 12:52:40 -0400 X-Greylist: delayed 314 seconds by postgrey-1.27 at vger.kernel.org; Thu, 22 Aug 2013 12:52:40 EDT Date: Thu, 22 Aug 2013 16:47:25 +0000 From: Christoph Lameter X-X-Sender: cl@gentwo.org To: Joonsoo Kim cc: Pekka Enberg , Andrew Morton , Joonsoo Kim , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 00/16] slab: overload struct slab over struct page to reduce memory usage In-Reply-To: <1377161065-30552-1-git-send-email-iamjoonsoo.kim@lge.com> Message-ID: <00000140a6ec66e5-a4d245c0-76b6-4a8b-9cf0-d941ca9e08b0-000000@email.amazonses.com> References: <1377161065-30552-1-git-send-email-iamjoonsoo.kim@lge.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-SES-Outgoing: 2013.08.22-54.240.9.58 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 994 Lines: 23 On Thu, 22 Aug 2013, Joonsoo Kim wrote: > And this patchset change a management method of free objects of a slab. > Current free objects management method of the slab is weird, because > it touch random position of the array of kmem_bufctl_t when we try to > get free object. See following example. The ordering is intentional so that the most cache hot objects are removed first. > To get free objects, we access this array with following pattern. > 6 -> 3 -> 7 -> 2 -> 5 -> 4 -> 0 -> 1 -> END Because that is the inverse order of the objects being freed. The cache hot effect may not be that significant since per cpu and per node queues have been aded on top. So maybe we do not be so cache aware anymore when actually touching struct slab. -- 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/