From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 23 Aug 2001 02:56:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 23 Aug 2001 02:56:16 -0400 Received: from fe000.worldonline.dk ([212.54.64.194]:61714 "HELO fe000.worldonline.dk") by vger.kernel.org with SMTP id ; Thu, 23 Aug 2001 02:56:07 -0400 Date: Thu, 23 Aug 2001 08:59:02 +0200 From: Jens Axboe To: Jes Sorensen Cc: Adam Radford , "'linux-kernel@vger.kernel.org'" , "'linux-scsi@vger.kernel.org'" Subject: Re: [patch] 3Ware 64 bit locking issues Message-ID: <20010823085902.M604@suse.de> In-Reply-To: <53B208BD9A7FD311881A009027B6BBFB9EAE47@siamese> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 22 2001, Jes Sorensen wrote: > >>>>> "Adam" == Adam Radford writes: > > Adam> Thanks for flags type fix and redundant pushf/popf fix. > Adam> Regarding your question about the error handling routines, the > Adam> 3ware driver uses the new style scsi error handling, so looking > Adam> through scsi_error.c, all calls to > Adam> hostt->eh_abort_handler() and hostt->eh_host_reset_handler() are > Adam> wrapped with a spin_lock_irqsave(&io_request_lock, flags) and > Adam> spin_unlock_irqrestore(&io_request_lock, flags) so they should > Adam> be okay. > > Hmm ok. However, since Jens is working on killing the io_request_lock > so something will need to get done when that happens. > > Jens, what is the strategy for that? Lots of the lower level hooks are done with io_request_lock required, the only one I've killed so far is ->detect() and that was mainly because it didn't fit with the new scheme (per-host locking, host not inited at this time). IMO it was a mistake to ever grab io_request_lock (or any other lock, for that matter) before calling into the lower levels -- it's not very clean and it makes progressing to a better locking structure harder. Basically we want to move the locking down a notch, so the mid layer is not responsible for providing reentrance protection for the low level drivers. It will be painfull... -- Jens Axboe