Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757543Ab0KJXwN (ORCPT ); Wed, 10 Nov 2010 18:52:13 -0500 Received: from mail-vw0-f46.google.com ([209.85.212.46]:59311 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757322Ab0KJXwM (ORCPT ); Wed, 10 Nov 2010 18:52:12 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=Nbo4YKfX3DB6whphhDIVxcIg/EUqP8s2pv5pyQtpZzYnsVfL2852a7Gr7WUoVr6eut WGEXZjBnKZVaKP28j/C0tW1/Fr7Qr1dIlGc/3qpxfzF09f2Xcad9MeHlLST+JWZPq3/F lZpmM9YBgFzrTfG4wf+T3zNmld3uuMaBVs+b8= Message-ID: <4CDB3028.6080605@garzik.org> Date: Wed, 10 Nov 2010 18:52:08 -0500 From: Jeff Garzik User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.12) Gecko/20101027 Fedora/3.1.6-1.fc13 Thunderbird/3.1.6 MIME-Version: 1.0 To: James Bottomley CC: linux-scsi , LKML Subject: Re: Patch added to scsi-rc-fixes-2.6: [SCSI] host lock push-down References: <201011102240.oAAMe86a001486@hera.kernel.org> <4CDB2A81.5030100@garzik.org> <1289432759.3016.63.camel@mulgrave.site> In-Reply-To: <1289432759.3016.63.camel@mulgrave.site> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1951 Lines: 50 On 11/10/2010 06:45 PM, James Bottomley wrote: > On Wed, 2010-11-10 at 18:28 -0500, Jeff Garzik wrote: >> On 11/10/2010 05:40 PM, James Bottomley wrote: >>> Your commit: >>> >>> [SCSI] host lock push-down >>> >>> Move the mid-layer's ->queuecommand() invocation from being locked >>> with the host lock to being unlocked to facilitate speeding up the >>> critical path for drivers who don't need this lock taken anyway. >>> >>> The patch below presents a simple SCSI host lock push-down as an >>> equivalent transformation. No locking or other behavior should change >>> with this patch. All existing bugs and locking orders are preserved. >>> >>> Minimal code disturbance was attempted with this change. Most drivers >>> needed only two one-line modifications for their host lock push-down. >>> >>> Signed-off-by: Jeff Garzik >>> Signed-off-by: James Bottomley >>> >>> has been added to the upstream SCSI tree >>> You can find it here: >> >> No comments on renaming ->queuecommand to something else? > > What we wondered about doing differently isn't really relevant for a > change log ... that should just really be about what was done (to avoid > confusion). Wasn't referring to the changelog (perhaps shouldn't have quoted that); just asking the question generally. >> The consequences are rather dire if this goes unnoticed, yes? > > You mean if there's a missed in-tree driver? Yes, but I took care to > make sure all SCSI drivers were accounted for. For out of tree drivers, > as with the eh lock push down, it's caveat emptor. Thinking about out-of-tree drivers, yes. Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/