Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932066Ab1BWD0U (ORCPT ); Tue, 22 Feb 2011 22:26:20 -0500 Received: from mga02.intel.com ([134.134.136.20]:53837 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754876Ab1BWD0T (ORCPT ); Tue, 22 Feb 2011 22:26:19 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.62,210,1297065600"; d="scan'208";a="712046277" Subject: Re: more dput lock contentions in 2.6.38-rc? From: Shaohua Li To: Nick Piggin Cc: "linux-fsdevel@vger.kernel.org" , lkml , Andrew Morton , Nick Piggin , "Chen, Tim C" In-Reply-To: <1295919258.1949.973.camel@sli10-conroe> References: <1295915725.1949.967.camel@sli10-conroe> <1295917864.1949.970.camel@sli10-conroe> <1295919258.1949.973.camel@sli10-conroe> Content-Type: text/plain; charset="UTF-8" Date: Wed, 23 Feb 2011 11:26:12 +0800 Message-ID: <1298431572.19589.1.camel@sli10-conroe> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1994 Lines: 44 On Tue, 2011-01-25 at 09:34 +0800, Shaohua Li wrote: > On Tue, 2011-01-25 at 09:26 +0800, Nick Piggin wrote: > > On Tue, Jan 25, 2011 at 12:11 PM, Shaohua Li wrote: > > > On Tue, 2011-01-25 at 09:04 +0800, Nick Piggin wrote: > > >> On Tue, Jan 25, 2011 at 11:35 AM, Shaohua Li wrote: > > >> > Hi, > > >> > we are testing dbench benchmark and see big drop of 2.6.38-rc compared > > >> > to 2.6.37 in several machines with 2 sockets or 4 sockets. We have 12 > > >> > disks mount to /mnt/stp/dbenchdata/sd*/ and dbench runs against data of > > >> > the disks. According to perf, we saw more lock contentions: > > >> > In 2.6.37: 13.00% dbench [kernel.kallsyms] [k] _raw_spin_lock > > >> > In 2.6.38-rc: 69.45% dbench [kernel.kallsyms] [k]_raw_spin_lock > > >> > - 69.45% dbench [kernel.kallsyms] [k] _raw_spin_lock > > >> > - _raw_spin_lock > > >> > - 48.41% dput > > >> > - 61.17% path_put > > >> > - 60.47% do_path_lookup > > >> > + 53.18% user_path_at > > >> > + 42.13% do_filp_open > > >> > + 4.69% user_path_parent > > >> > > >> What filesystems are mounted on the path? > > > ext3 or ext4 > > > > ext3 or 4 along every step of the path? Are there > > any acls loaded, or security policy running? > all disks are formated with the same fs, just some machines use ext3 and > others ext4. no we don't have acl or security policy. > > It may be possible that they're all coming from > > /proc/ access. > I added trace in dput just after the lock taken. and most files are '/', > 'mnt', 'stp'. the percentage of 'proc' is small actually. Hi Nick, Anything I can test for this issue? Thanks, Shaohua -- 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/