From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Christie Subject: Re: [PATCH RFC] allow bio code to unmap sg io requests and have blk_execute_rq_nowait bounce bios Date: Sat, 06 Aug 2005 11:25:00 -0500 Message-ID: <42F4E45C.90106@cs.wisc.edu> References: <1122628800.8900.22.camel@max> <20050802084905.GC22569@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from sabe.cs.wisc.edu ([128.105.6.20]:2442 "EHLO sabe.cs.wisc.edu") by vger.kernel.org with ESMTP id S263242AbVHFQZU (ORCPT ); Sat, 6 Aug 2005 12:25:20 -0400 In-Reply-To: <20050802084905.GC22569@suse.de> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Jens Axboe Cc: SCSI Mailing List Jens Axboe wrote: > On Fri, Jul 29 2005, Mike Christie wrote: > >>Hey Jens and James, >> >>The inlined patch moves the bounce buffer handling to blk_execute_rq_nowait >>so the scsi, sg io and cdrom code does not have to handle it. To accomplish >>this I moved the bio_uncopy_user to a bi_end_io function and bio_unmap_user >>to a work struct that is schedule from a bi_end_io functions. Did you say >>you disliked the idea of calling bio_unmap_user from a work struct - don't >>remember and I lost my emails when I moved? :( > > > It's probably alright, it cleans up the code a lot. It will cost some > extra context switches, but I'm naively hoping that for busy io we will > have good batching of the processing anyways. > Doh! I ported sg.c and noticed I messed up. copy_to_user must be called from user context so my patch does not work for that path.