From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752532Ab1EQGKe (ORCPT ); Tue, 17 May 2011 02:10:34 -0400 Received: from mga09.intel.com ([134.134.136.24]:55643 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752284Ab1EQGKd (ORCPT ); Tue, 17 May 2011 02:10:33 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.65,223,1304319600"; d="scan'208";a="643632138" Subject: Re: Perfromance drop on SCSI hard disk From: "Alex,Shi" To: "Li, Shaohua" Cc: Jens Axboe , "James.Bottomley@hansenpartnership.com" , "linux-kernel@vger.kernel.org" In-Reply-To: <1305535071.21534.2122.camel@debian> References: <1305009600.21534.587.camel@debian> <4DCC4340.6000407@fusionio.com> <1305247704.2373.32.camel@sli10-conroe> <1305255717.2373.38.camel@sli10-conroe> <1305533054.2375.45.camel@sli10-conroe> <1305535071.21534.2122.camel@debian> Content-Type: text/plain; charset="UTF-8" Date: Tue, 17 May 2011 14:09:25 +0800 Message-ID: <1305612565.21534.2177.camel@debian> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2011-05-16 at 16:37 +0800, Alex,Shi wrote: > > > what I mean is current sdev (other devices too) can still be added into > > > starved list, so only does async execute for current q isn't enough, > > > we'd better put whole __scsi_run_queue into workqueue. something like > > > below on top of yours, untested. Not sure if there are other recursive > > > cases. > > verified the regression can be fully fixed by your patch (with my > > suggested fix to avoid race). Can we put a formal patch upstream? > > Yes, we tested Jens patch alone and plus Shaohua's patch too. Both of > them recovered SAS disk performance too. Now I am testing them on SSD > disk with kbuild and fio cases, In theory, they will both work. > As expected, both patches has no effect on SSD disks in JBD. > > > > Thanks, > > Shaohua > > >