Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934351Ab1ESS11 (ORCPT ); Thu, 19 May 2011 14:27:27 -0400 Received: from mx2.fusionio.com ([66.114.96.31]:57177 "EHLO mx2.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934350Ab1ESS1W (ORCPT ); Thu, 19 May 2011 14:27:22 -0400 X-ASG-Debug-ID: 1305829640-01de28096b4f8d0001-xx1T2L X-Barracuda-Envelope-From: JAxboe@fusionio.com Message-ID: <4DD56104.6080801@fusionio.com> Date: Thu, 19 May 2011 20:27:16 +0200 From: Jens Axboe MIME-Version: 1.0 To: "Alex,Shi" CC: "Li, Shaohua" , "James.Bottomley@hansenpartnership.com" , "linux-kernel@vger.kernel.org" Subject: Re: Perfromance drop on SCSI hard disk 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> <1305612565.21534.2177.camel@debian> <4DD221BE.3040406@fusionio.com> <1305793580.22968.155.camel@debian> X-ASG-Orig-Subj: Re: Perfromance drop on SCSI hard disk In-Reply-To: <1305793580.22968.155.camel@debian> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Barracuda-Connect: mail1.int.fusionio.com[10.101.1.21] X-Barracuda-Start-Time: 1305829640 X-Barracuda-URL: http://10.101.1.181:8000/cgi-mod/mark.cgi X-Barracuda-Spam-Score: 0.00 X-Barracuda-Spam-Status: No, SCORE=0.00 using global scores of TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=9.0 tests= X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.2.64212 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 961 Lines: 25 On 2011-05-19 10:26, Alex,Shi wrote: > >> I will queue up the combined patch, it looks fine from here as well. >> > > When I have some time to study Jens and shaohua's patch today. I find a > simpler way to resolved the re-enter issue on starved_list. Following > Jens' idea, we can just put the starved_list device into kblockd if it > come from __scsi_queue_insert(). > It can resolve the re-enter issue and recover performance totally, and > need not a work_struct in every scsi_device. The logic/code also looks a > bit simpler. > What's your opinion of this? Isn't this _identical_ to my original patch, with the added async run of the queue passed in (which is important, an oversight)? -- Jens Axboe -- 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/