From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boaz Harrosh Subject: Re: scsi: Drivers not ready for sg-chaining Date: Sun, 10 Feb 2008 18:36:17 +0200 Message-ID: <47AF2801.5060806@panasas.com> References: <478F8435.5000907@panasas.com> <478F878F.6040807@panasas.com> <1202658166.3136.44.camel@localhost.localdomain> <47AF2188.2030400@panasas.com> <1202660210.3136.51.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from gw-colo-pa.panasas.com ([66.238.117.130]:10142 "EHLO cassoulet.panasas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751259AbYBJQgY (ORCPT ); Sun, 10 Feb 2008 11:36:24 -0500 In-Reply-To: <1202660210.3136.51.camel@localhost.localdomain> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Bottomley Cc: linux-scsi On Sun, Feb 10 2008 at 18:16 +0200, James Bottomley wrote: > On Sun, 2008-02-10 at 18:08 +0200, Boaz Harrosh wrote: >> My patches *do not* attempt to fix the sg_chaining support. They only >> make all the drivers that use SG_ALL to use SCSI_MAX_SG_SEGMENTS. >> One by One, and not globally as your suggestion. > > Yes, I know ... but it does need fixing for the listed drivers. That is another patchset that its time as not yet come. Once every thing settles I will send these too. That's why I put the list as a reminder for me to check upon later. > >> This is for two reasons. >> 1. So drivers can be individually fixed and in the patch that fixes them >> they can go back to SG_ALL. > > No, it's so SG_ALL can mean use chaining ... I'm not sure that's > desirable for the default value. Particularly for devices that key > internal sglist arrays off SG_ALL > I have fixed *all* these drivers that are based off SG_ALL for table sizes, and all other reasons. exactly so the SG_ALL will continue to mean what it means in English. (And this was triggered by your request) >> 2. Those drivers that have been using SG_ALL correctly and were converted >> to support sg-chaining are not penalized because of bad/old drivers > > I don't see they're penalised this way either ... they just have to set > a higher value in their host template. > It was you who wanted that to be SG_ALL. I wanted just an hard coded = ~0. >> 3. Some drivers in this patchset are converted to use a real internal >> driver limit. That does not necessarily match SCSI_MAX_SG_SEGMENTS. >> In the event that SCSI_MAX_SG_SEGMENTS wants to change. > > Yes, I looked at those they're all either safe or currently (eventually) > do the right thing. > What ?? >> The bulk of the patchset is very much mechanical and is not dangerous >> and was ACKed by the more important maintainers. (That is where the >> changes are more then trivial). So I don't see why they cannot get >> a proper review and be accepted. Instead of doing the safe but the >> wrong thing, cross tree. > > What's wrong about this? > I don't want to repeat myself. If it's fine with you, I trust your final judgment. You are welcome to submit a patch that fixes all the good drivers that are regressed by your suggestion. > James > > Boaz