From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH 23/24] advansys: Improve interrupt handler Date: Fri, 27 Jul 2007 13:39:03 -0400 Message-ID: <46AA2DB7.4010707@garzik.org> References: <20070727134038.GC21219@parisc-linux.org> <11855437542538-git-send-email-matthew@wil.cx> <46AA05ED.2060208@garzik.org> <20070727145336.GK21219@parisc-linux.org> <46AA07CC.9090004@garzik.org> <20070727150420.GL21219@parisc-linux.org> <46AA0B70.9060108@garzik.org> <20070727152520.GM21219@parisc-linux.org> <46AA150A.5090804@garzik.org> <20070727173613.GN21219@parisc-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:59693 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757951AbXG0RjG (ORCPT ); Fri, 27 Jul 2007 13:39:06 -0400 In-Reply-To: <20070727173613.GN21219@parisc-linux.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Matthew Wilcox Cc: linux-scsi@vger.kernel.org Matthew Wilcox wrote: > On Fri, Jul 27, 2007 at 11:53:46AM -0400, Jeff Garzik wrote: >> Matthew Wilcox wrote: >>> I still say it's an improvement over scanning the list of scsi hosts >>> looking for any that have work pending whenever any interrupt comes in. >> Having the kernel interrupt subsystem implement a loop for you is >> completely utterly unusual, slow, silly, and likely to get broken when >> people futz with the interrupt system core. It probably has edge cases >> too, like screwing with the screaming interrupt detection code. >> >> The kernel interrupt subsystem is not meant to be abused in that way. > > I think what you're missing is: This isn't new. The advansys driver > was *already* requesting the same interrupt twice for EISA boards. > It's just that before, when an interrupt happened on the EISA board, > it would scan all Scsi_Hosts twice, and now it scans this pair of boards > once each. > > It may not be elegant, it may not be the best way, but it *is* a > monotonic improvement. So please, calm down. You're expanding wrongheaded use. That's moving in the wrong direction. Jeff