From mboxrd@z Thu Jan 1 00:00:00 1970 From: Doug Ledford Subject: Re: [PATCH + RFC] Beginning of some updates to scsi mid layer Date: Mon, 1 Jul 2002 15:15:53 -0400 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <20020701151553.G776@redhat.com> References: <20020701225037.E3271-100000@localhost.my.domain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: ; from mjacob@feral.com on Mon, Jul 01, 2002 at 12:08:03PM -0700 List-Id: linux-scsi@vger.kernel.org To: Matthew Jacob Cc: =?iso-8859-1?Q?G=E9rard_Roudier?= , Jeremy Higdon , Martin Peschke3 , Pete Zaitcev , linux-scsi@vger.kernel.org On Mon, Jul 01, 2002 at 12:08:03PM -0700, Matthew Jacob wrote: > Yes, exponential backoff is good in a lot of cases. BTW- this is something I > want to put into cam_periph_error for FreeBSD- I want to make the retry after > selection timeout also have exponential delays up to retry count. Hmmm...what's the purpose on this BTW? Selection timeouts on what, fiber or SPI or something else? > In private mail with Doug && Pete, I managed to put myself into an untenable > position. The problem here is that we don't have end-to-end flow control, so > we have to *guess* when it might be good to try again. Yep. Experimentation can be your friend on that. That's what I did to come up with the alghorithm I was quoting. However, I didn't try exponential backoff so I make no claims that it wouldn't in fact be better. -- Doug Ledford 919-754-3700 x44233 Red Hat, Inc. 1801 Varsity Dr. Raleigh, NC 27606