Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756607Ab2BGBMS (ORCPT ); Mon, 6 Feb 2012 20:12:18 -0500 Received: from mga02.intel.com ([134.134.136.20]:43314 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756548Ab2BGBMR (ORCPT ); Mon, 6 Feb 2012 20:12:17 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,351,1309762800"; d="scan'208";a="107130266" Subject: Re: [patch]block: fix ioc locking warning From: Shaohua Li To: Tejun Heo Cc: Linus Torvalds , Vivek Goyal , Jens Axboe , lkml , Knut Petersen , mroos@linux.ee In-Reply-To: <20120207005900.GF21292@google.com> References: <20120206151219.GC30752@redhat.com> <4F2FFB21.9000202@kernel.dk> <20120206163721.GF30752@redhat.com> <20120206164428.GA21292@google.com> <20120206172706.GB21292@google.com> <20120206203604.GC21292@google.com> <20120207003948.GE21292@google.com> <1328575430.21268.69.camel@sli10-conroe> <20120207005900.GF21292@google.com> Content-Type: text/plain; charset="UTF-8" Date: Tue, 07 Feb 2012 09:10:20 +0800 Message-ID: <1328577020.21268.73.camel@sli10-conroe> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1047 Lines: 26 On Mon, 2012-02-06 at 16:59 -0800, Tejun Heo wrote: > On Tue, Feb 07, 2012 at 08:43:50AM +0800, Shaohua Li wrote: > > Quite simple, copy kernel source to tmpfs in tight memory environment. > > This will trigger swap. The bisection result appears stable. > > Looked through the commit again but it really doesn't change fast > paths. The only paths which can be slower are ioc and q exits. Can > you please do the followings? > > * Share the script used for microbench. Maybe it somehow exposes > slower exit path? How much regression are we talking about? I need strip the script out from our test framework, but it essentially is a 'time copy -a tmpfs/kernelsource tmpfs/copy'. The time increased ~20% with 3.3-rc1. > * Test with the this_q != locked_q trylock patch. sure. 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/