Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756446Ab0DFPm7 (ORCPT ); Tue, 6 Apr 2010 11:42:59 -0400 Received: from nlpi129.sbcis.sbc.com ([207.115.36.143]:47565 "EHLO nlpi129.prodigy.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753145Ab0DFPmx (ORCPT ); Tue, 6 Apr 2010 11:42:53 -0400 Date: Tue, 6 Apr 2010 10:41:47 -0500 (CDT) From: Christoph Lameter X-X-Sender: cl@router.home To: "Zhang, Yanmin" cc: Tejun Heo , Pekka Enberg , alex.shi@intel.com, "linux-kernel@vger.kernel.org" , "Ma, Ling" , "Chen, Tim C" , Andrew Morton Subject: Re: hackbench regression due to commit 9dfc6e68bfe6e In-Reply-To: <1270542497.2078.123.camel@ymzhang.sh.intel.com> Message-ID: References: <1269506457.4513.141.camel@alexs-hp.sh.intel.com> <1269570902.9614.92.camel@alexs-hp.sh.intel.com> <1270114166.2078.107.camel@ymzhang.sh.intel.com> <1270195589.2078.116.camel@ymzhang.sh.intel.com> <4BBA8DF9.8010409@kernel.org> <1270542497.2078.123.camel@ymzhang.sh.intel.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1528 Lines: 40 On Tue, 6 Apr 2010, Zhang, Yanmin wrote: > Thanks. I tried 2 and 4 times and didn't see much improvement. > I checked /proc/vamallocinfo and it doesn't have item of pcpu_get_vm_areas > when I use 4 times of PERCPU_DYNAMIC_RESERVE. > I used perf to collect dtlb misses and LLC misses. dtlb miss data is not > stable. Sometimes, we have a bigger dtlb miss, but get a better result. > > LLC misses data are more stable. Only LLC-load-misses is the clear sign now. > LLC-store-misses has no big difference. LLC-load-miss is exactly what condition? The cacheline environment in the hotpath should only include the following cache lines (without debugging and counters): 1. The first cacheline from the kmem_cache structure (This is different from the sitation before the 2.6.34 changes. Earlier some critical values (object length etc) where available from the kmem_cache_cpu structure. The cacheline containing the percpu structure array was needed to determome the kmem_cache_cpu address!) 2. The first cacheline from kmem_cache_cpu 3. The first cacheline of the data object (free pointer) And in case of a kfree/ kmem_cache_free: 4. Cacheline that contains the page struct of the page the object resides in. Can you post the .config you are using and the bootup messages? -- 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/