From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 28 Aug 2001 07:42:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 28 Aug 2001 07:42:47 -0400 Received: from fe100.worldonline.dk ([212.54.64.211]:40453 "HELO fe100.worldonline.dk") by vger.kernel.org with SMTP id ; Tue, 28 Aug 2001 07:42:35 -0400 Date: Tue, 28 Aug 2001 13:45:45 +0200 From: Jens Axboe To: Christoph Rohland Cc: Linux Kernel , "David S. Miller" Subject: Re: [patch] zero-bounce block highmem I/O, #13 Message-ID: <20010828134545.N642@suse.de> In-Reply-To: <20010827123700.B1092@suse.de> <20010828125520.L642@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 28 2001, Christoph Rohland wrote: > Hi Jens, > > On Tue, 28 Aug 2001, Jens Axboe wrote: > > On Tue, Aug 28 2001, Christoph Rohland wrote: > >> Hi Jens, > >> > >> I tested both #11 and #13 on my 8GB machine with sym53c8xx. The > >> initialization of a SAP DB database takes 20 minutes with 2.4.9 and > >> with 2.4.9+b13 it took nearly 2.5 hours :-( > > > > DaveM hinted that it's probably the bounce test failing, so it's > > bouncing all the time. That would explain the much worse > > performance. Could you try with this incremental patch on top of > > b13 for 2.4.9? I still want to see the boot detection info, btw. > > Apparently it did not help. See attachments: vmstat was 'vmstat > 5'. The b13 output is only the end. The b13-1 is still running but the > blockout rate is again low. So I do not wait another 2 hours... Nope fine, no need to wait :-) The -2 patch I sent should fix it, performance looks good here (just a 5min test run to verify). What happened was that we would fall back to single segment requests all the time. A real performance killer for SCSI. -- Jens Axboe