From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752775AbbKKRhZ (ORCPT ); Wed, 11 Nov 2015 12:37:25 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36899 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751414AbbKKRhW (ORCPT ); Wed, 11 Nov 2015 12:37:22 -0500 Date: Wed, 11 Nov 2015 12:37:20 -0500 From: Mike Snitzer To: Christoph Hellwig Cc: Mike Christie , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, device-mapper development , linux-fsdevel@vger.kernel.org, Bart Van Assche , drbd-dev@lists.linbit.com Subject: Re: [RFC PATCH 00/32] separate operations from flags in the bio/request structs Message-ID: <20151111173719.GB12236@redhat.com> References: <1446654807-6935-1-git-send-email-mchristi@redhat.com> <563A36FC.6010001@sandisk.com> <563A3813.5010604@cs.wisc.edu> <20151107102309.GE12117@infradead.org> <5642F3F4.2060007@cs.wisc.edu> <20151111112846.GA358@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151111112846.GA358@infradead.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 11 2015 at 6:28am -0500, Christoph Hellwig wrote: > On Wed, Nov 11, 2015 at 01:53:24AM -0600, Mike Christie wrote: > > We no longer have the bvec merge functions so the original reason given > > in the thread/patch Bart referenced is no longer valid. > > > > Offlist it was suggested that dropping the argument from submit_bio > > might still improve performance, but I modified xfs and dm and did some > > testing and did not see anything. > > > > So the change is not needed, and it would only be done because people > > feel it would improve the interface. > > I would defintively prefer the changed interface, and to me it also > looks like it would make your overall patch simpler. If you disagree > feel free to keep it as-is for now and I'll do another pass later. The less churn the better. But honestly, not quite following the logic on why all this flag-day churn is needed. BUT if it needs to happen, because we'll soon hit a wall on supported operations via REQ_*, now is as good a time as any -- but best to limit the change to the flags IMHO.