From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261306AbVGLMi3 (ORCPT ); Tue, 12 Jul 2005 08:38:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261412AbVGLMi2 (ORCPT ); Tue, 12 Jul 2005 08:38:28 -0400 Received: from 167.imtp.Ilyichevsk.Odessa.UA ([195.66.192.167]:42459 "HELO port.imtp.ilyichevsk.odessa.ua") by vger.kernel.org with SMTP id S261306AbVGLMgi (ORCPT ); Tue, 12 Jul 2005 08:36:38 -0400 From: Denis Vlasenko To: Martin Schwidefsky Subject: Re: [patch 7/12] s390: fba dasd i/o errors. Date: Tue, 12 Jul 2005 15:36:19 +0300 User-Agent: KMail/1.5.4 Cc: akpm@osdl.org, Horst Hummel , linux-kernel@vger.kernel.org References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="koi8-r" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200507121536.19848.vda@ilport.com.ua> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 12 July 2005 13:36, Martin Schwidefsky wrote: > > > @@ -354,6 +354,8 @@ dasd_fba_build_cp(struct dasd_device * d > > > } > > > cqr->device = device; > > > cqr->expires = 5 * 60 * HZ; /* 5 minutes */ > > > + cqr->retries = 32; > > > > 2..4 maybe, but 32? This isn't tiny by any account. > > Are you arguing the use of the adjective "tiny" or the technical > aspects of using 32 as the number of retries for dasd fba? > In the dasd driver we use a retry count of 255 as "standard", so > 32 is indeed much smaller than that. If you can call it tiny, > well who cares?? I meant that 32 retries is too many. Retries tend to multiply. If OS does N retries per failed attempt and disk drive does M attempts per attempt, you end up with N*M retries. Add a few 'retrying' layers, and you have a 'I cannot umount this fscking scratched CDROM, maybe tomorrow' type disaster. It's better to err to the smaller number of attempts. -- vda