From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758220AbaGWQgJ (ORCPT ); Wed, 23 Jul 2014 12:36:09 -0400 Received: from mail-qa0-f50.google.com ([209.85.216.50]:55135 "EHLO mail-qa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756598AbaGWQgH (ORCPT ); Wed, 23 Jul 2014 12:36:07 -0400 Date: Wed, 23 Jul 2014 12:36:01 -0400 From: Tejun Heo To: Bartlomiej Zolnierkiewicz Cc: Jesse Brandeburg , Mike Qiu , "linux-kernel@vger.kernel.org" , linux-ide@vger.kernel.org, wenxiong@linux.vnet.ibm.com, brking@linux.vnet.ibm.com, zhenghch@cn.ibm.com, haokexin@gmail.com, Peter Hurley , Peter Zijlstra , Alexey Kardashevskiy Subject: Re: [PATCH libata/for-3.16-fixes] libata: introduce ata_host->n_tags to avoid oops on SAS controllers Message-ID: <20140723163601.GE7103@htj.dyndns.org> References: <1406040688-1762-1-git-send-email-qiudayu@linux.vnet.ibm.com> <20140722201109.GN13851@htj.dyndns.org> <20140723144631.GA7103@htj.dyndns.org> <4586703.PjmVDM7Oct@amdc1032> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4586703.PjmVDM7Oct@amdc1032> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Wed, Jul 23, 2014 at 06:31:58PM +0200, Bartlomiej Zolnierkiewicz wrote: > Hmmm, wasn't ATA_MAX_QUEUE used before not ATA_MAX_QUEUE - 1? > > It seems that after your patch the loop in the ata_qc_new() will use > only 30 tags and not 31 ones? It was always 31 (ATA_MAX_QUEUE - 1) with the tag 31 reserved for EH commands. The previous patch just used limit value which is one too high. I'm planning to change that but this is the way it has always been. Thanks. -- tejun