From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753618AbbC0IS1 (ORCPT ); Fri, 27 Mar 2015 04:18:27 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:59194 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752793AbbC0ISY (ORCPT ); Fri, 27 Mar 2015 04:18:24 -0400 Date: Fri, 27 Mar 2015 01:18:22 -0700 From: Christoph Hellwig To: Andrew Morton Cc: Milosz Tanski , linux-kernel@vger.kernel.org, Christoph Hellwig , linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, Mel Gorman , Volker Lendecke , Tejun Heo , Jeff Moyer , "Theodore Ts'o" , Al Viro , linux-api@vger.kernel.org, Michael Kerrisk , linux-arch@vger.kernel.org, Dave Chinner Subject: Re: [PATCH v7 0/5] vfs: Non-blockling buffered fs read (page cache only) Message-ID: <20150327081822.GA28669@infradead.org> References: <20150326202824.65d03787.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150326202824.65d03787.akpm@linux-foundation.org> User-Agent: Mutt/1.5.23 (2014-03-12) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 26, 2015 at 08:28:24PM -0700, Andrew Morton wrote: > I still don't understand why pwritev() exists. We discussed this last > time but it seems nothing has changed. I'm not seeing here an adequate > description of why it exists nor a justification for its addition. pwritev2? I have patches to support per-I/O O_DSYNC with it, lots of folks including Samba and SCSI targets want this because their protocols support it. The patches were posted with earlier versions of Miklos series. It's cleaner to add the two system calls in go when we plan using them anyway and have symmetric infrastructure, and I did not hear any disagreement with that on LSF. Did you skip this session? > And (again) we've discussed this before, but the patchset gets resent > as if nothing had happened. We had long discussiosn about it both here and at LSF. We had everyone agree and nod there, and only your repeated argument here, so maybe it's not Miklos who is disonnected but you? Also that whole fincore argument is rather hypothetic - it's only been pushed in to ugly to live multiplexers that also expose things like pfns, while with preadv2 we have a trivial and easy to use API read to merge, and various consumerms just waiting for it.