From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965257AbVHJStz (ORCPT ); Wed, 10 Aug 2005 14:49:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965259AbVHJSty (ORCPT ); Wed, 10 Aug 2005 14:49:54 -0400 Received: from mailfe09.tele2.fr ([212.247.155.12]:47260 "EHLO swip.net") by vger.kernel.org with ESMTP id S965257AbVHJStx (ORCPT ); Wed, 10 Aug 2005 14:49:53 -0400 X-T2-Posting-ID: g63wq726D5fsXb2UbU6LU0KOXzHnTHjCzHZ35sC2MDs= Message-ID: <42FA4C44.5040609@astek.fr> Date: Wed, 10 Aug 2005 20:49:40 +0200 From: Frederic TEMPORELLI - astek User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; fr; rv:1.7.3) Gecko/20040910 X-Accept-Language: fr, en MIME-Version: 1.0 To: Linux Kernel CC: James Bottomley , SCSI Mailing List Subject: Re: [PATCH] remove name length check in a workqueue References: <1123683544.5093.4.camel@mulgrave> <20050810100523.0075d4e8.akpm@osdl.org> <1123694672.5134.11.camel@mulgrave> <20050810103733.42170f27.akpm@osdl.org> <1123696466.5134.23.camel@mulgrave> In-Reply-To: <1123696466.5134.23.camel@mulgrave> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org James Bottomley a écrit : >Well, but the other alternative is that we hit arbitrary BUG_ON() limits >in systems that create numbered workqueues which is rather contrary to >our scaleability objectives, isn't it? > >I think I'd rather the name truncation than have to respond to kernel >BUG()'s. If someone really has a problem with the appearance of ps, >they can always increase TASK_COMM_LEN. > > > >>We could truncate the name before adding the CPU number, but it sounds >>saner to just prevent anyone passing in excessively long names. Via >>BUG_ON, say ;) >> >>What's the actual problem? >> >> > >What I posted originally; the current SCSI format for a workqueue: >scsi_wq_%d hits the bug after the host number rises to 100, which has >been seen by some enterprise person with > 100 HBAs. > >The reason for this name is that the error handler thread is called >scsi_eh_%d; so we could rename all our threads to avoid this, but one >day someone will come along with a huge enough machine to hit whatever >limit we squeeze it down to. > >James > > > In scsi layer (drivers/scsi/hosts.c), wq name length is limited to KOBJ_NAME_LEN due to the snprintf . may be nice to use same limit if BUG_ON is kept... but why NULL isn't returned, then ? ;-) -- Tempo