From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 16/32] scsi/be2iscsi,qla2xxx: convert to alloc_workqueue() Date: Thu, 3 Feb 2011 10:31:20 +0100 Message-ID: <20110203093120.GC2570@htj.dyndns.org> References: <1294062595-30097-1-git-send-email-tj@kernel.org> <1294062595-30097-17-git-send-email-tj@kernel.org> <4D489B09.9010906@cs.wisc.edu> <20110202102521.GA24115@htj.dyndns.org> <4D49C172.3040600@cs.wisc.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4D49C172.3040600@cs.wisc.edu> Sender: linux-kernel-owner@vger.kernel.org To: Mike Christie Cc: linux-kernel@vger.kernel.org, Jayamohan Kallickal , Andrew Vasquez , "James E.J. Bottomley" , linux-scsi@vger.kernel.org List-Id: linux-scsi@vger.kernel.org Hello, Mike. On Wed, Feb 02, 2011 at 02:41:22PM -0600, Mike Christie wrote: > On 02/02/2011 04:25 AM, Tejun Heo wrote: > >usually necessary. The queue of pending works tend to be short and > >consumed pretty fast. > > What if we want to do something that could take a while, like doing > recovery of a device/transport (so you have to send resets and > logouts/logins and wait for the results but they could take a while > if they timeout), should we be using something other than a > workqueue so it does not interfere with other users? As long as you don't use ordered workqueue, it wouldn't be a problem. The max concurrency is determined by @max_active parameter to alloc_workqueue() and workqueue will try to provide concurrency upto the limit on demand as long as resources are available. Thanks. -- tejun