From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Christie Subject: Re: [PATCH] [14/20] Don't disable direct_io for unchecked_isa_dma in st.c Date: Thu, 27 Mar 2008 12:26:54 -0500 Message-ID: <47EBD8DE.4080502@cs.wisc.edu> References: <20080307653.720459648@firstfloor.org> <20080307175414.08C981B41AE@basil.firstfloor.org> <20080314135135.GT17940@kernel.dk> <20080314142412.GA30325@infradead.org> <47DD14F7.4070607@panasas.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from sabe.cs.wisc.edu ([128.105.6.20]:36533 "EHLO sabe.cs.wisc.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751705AbYC0R2E (ORCPT ); Thu, 27 Mar 2008 13:28:04 -0400 In-Reply-To: <47DD14F7.4070607@panasas.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Boaz Harrosh Cc: Christoph Hellwig , Jens Axboe , Andi Kleen , James.Bottomley@HansenPartnership.com, linux-scsi@vger.kernel.org Boaz Harrosh wrote: > On Fri, Mar 14 2008 at 16:24 +0200, Christoph Hellwig wrote: >> On Fri, Mar 14, 2008 at 02:51:35PM +0100, Jens Axboe wrote: >>> Are you sure? Seems to me that st builds its own list with >>> get_user_pages() for direct io, where will that get bounced? The block >>> layer will only bounce things that are mapped directly, so if st used >>> blk_rq_map_kern() and inserted that request in the queue, we could >>> proceed with killing that check in st. >> Which shouldn't be all too difficult and would be the right thing to >> do. We really need someone to sit down and convert st/osst/sg to use >> the proper block layer helpers. >> > > First they do. They all call scsi_execute_async which at the end produces > a BIO and then calls blk_execute_nowait(). and all is swell. > > Second some one did, long a go, and have submitted them rebased more then 3 > times. I'd say their time is do long a go. (I mean Mike Christie) > > Mike, please, do you have these patches on a public git somewhere I want to help > push them. > Sorry I have been so bad with my linux-scsi email. Here is my current patches: http://kernel.org/pub/linux/kernel/people/mnc/sg/sg-bioset17/ They are very broken (patch -p1 wise), because of all the block layer changes. I got around to converting st. It is not tested. I just need to convert osst and we can kill scsi_execute_async.