From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263769AbUHWMRy (ORCPT ); Mon, 23 Aug 2004 08:17:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263735AbUHWMRy (ORCPT ); Mon, 23 Aug 2004 08:17:54 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:9632 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S263769AbUHWMRD (ORCPT ); Mon, 23 Aug 2004 08:17:03 -0400 Date: Mon, 23 Aug 2004 14:15:41 +0200 From: Jens Axboe To: Bartlomiej Zolnierkiewicz Cc: Linux Kernel Subject: Re: serialize access to ide device Message-ID: <20040823121540.GN2301@suse.de> References: <20040802131150.GR10496@suse.de> <200408211643.55531.bzolnier@elka.pw.edu.pl> <20040821162155.GC7490@suse.de> <200408211913.47982.bzolnier@elka.pw.edu.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200408211913.47982.bzolnier@elka.pw.edu.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Aug 21 2004, Bartlomiej Zolnierkiewicz wrote: > On Saturday 21 August 2004 18:21, Jens Axboe wrote: > > On Sat, Aug 21 2004, Bartlomiej Zolnierkiewicz wrote: > > > On Saturday 21 August 2004 12:32, Jens Axboe wrote: > > > > > What about adding new kind of REQ_SPECIAL request and converting > > > > > set_using_dma(), set_xfer_rate(), ..., to be callback functions for > > > > > this request? > > > > > > > > > > This should be a lot cleaner and will cover 100% cases. > > > > > > > > That will still only serialize per-channel. But yes, a lot cleaner. > > > > > > per hwgroup not per channel > > > (serializing per host device will be better but requires even more work) > > > > Sorry yes hwgroup, that's what I meant. The case I worried about in my > > patch (and noted) is that it doesn't cover per-hwif and neither would a > > special request. > > I guess you meant 'per-host' because hwif == channel. > > [ You are of course right for about 'per-host' case. ] Yep, per host. So REQ_SPECIAL-like approach is cleaner, but doesn't cover more cases than a simple hwif pinning would anyways. You'd need some code to quisce the host in any case. -- Jens Axboe