From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH] [14/20] Don't disable direct_io for unchecked_isa_dma in st.c Date: Fri, 14 Mar 2008 14:51:35 +0100 Message-ID: <20080314135135.GT17940@kernel.dk> References: <20080307653.720459648@firstfloor.org> <20080307175414.08C981B41AE@basil.firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from brick.kernel.dk ([87.55.233.238]:18860 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752218AbYCNNvi (ORCPT ); Fri, 14 Mar 2008 09:51:38 -0400 Content-Disposition: inline In-Reply-To: <20080307175414.08C981B41AE@basil.firstfloor.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Andi Kleen Cc: James.Bottomley@HansenPartnership.com, linux-scsi@vger.kernel.org On Fri, Mar 07 2008, Andi Kleen wrote: > > Block layer bounces anyways. 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. -- Jens Axboe