From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756533Ab2BGA7H (ORCPT ); Mon, 6 Feb 2012 19:59:07 -0500 Received: from mail-iy0-f174.google.com ([209.85.210.174]:38765 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755883Ab2BGA7F (ORCPT ); Mon, 6 Feb 2012 19:59:05 -0500 Date: Mon, 6 Feb 2012 16:59:00 -0800 From: Tejun Heo To: Shaohua Li Cc: Linus Torvalds , Vivek Goyal , Jens Axboe , lkml , Knut Petersen , mroos@linux.ee Subject: Re: [patch]block: fix ioc locking warning Message-ID: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1328575430.21268.69.camel@sli10-conroe> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? * Test with the this_q != locked_q trylock patch. Thanks. -- tejun