From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [RFC PATCH 2.6.9-rc2] Add sysfs queue depth override to qla2xxx Date: Tue, 28 Sep 2004 22:12:57 +0200 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <20040928201257.GA22509@suse.de> References: <20040928193614.GB192475@sgi.com> <1096401196.2008.97.camel@mulgrave> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from ns.virtualhost.dk ([195.184.98.160]:65184 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S267776AbUI1UNX (ORCPT ); Tue, 28 Sep 2004 16:13:23 -0400 Content-Disposition: inline In-Reply-To: <1096401196.2008.97.camel@mulgrave> List-Id: linux-scsi@vger.kernel.org To: James Bottomley Cc: Jeremy Higdon , Andrew Vasquez , SCSI Mailing List On Tue, Sep 28 2004, James Bottomley wrote: > On Tue, 2004-09-28 at 15:36, Jeremy Higdon wrote: > > I was trying to be conservative -- I didn't know the reason for > > that limit. By all means, let's remove it then. > > > > Would you like me to regenerate the patch, or do you just want > > to apply it to your internal source that will eventually be > > fed back to us? > > Well, don't go overboard on this ... there is a limit to the number of > outstanding requests any queue can have at one time...there's not much > point going over that since the block layer will throttle you when you > reach it. I think it's 128, but it might be 256 ... but anyway, not > much larger. That depends on both the io scheduler and the nr_requests setting, I don't think you should rely on any imposed block layer limit. -- Jens Axboe