Return-Path: Received: from mx142.netapp.com ([216.240.21.19]:62091 "EHLO mx142.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753249AbdDQP5u (ORCPT ); Mon, 17 Apr 2017 11:57:50 -0400 Subject: Re: [nfsv4] Inter server-side copy performance To: Olga Kornievskaia , "J. Bruce Fields" CC: "linux-nfs@vger.kernel.org" , "nfsv4@ietf.org" References: <20170413174515.GA5140@fieldses.org> <59BDF7CA-78BB-42FC-8BC4-95101F5E1EC7@netapp.com> <20170417133604.GA22694@fieldses.org> From: Anna Schumaker Message-ID: <44273d82-18b5-a6c7-4c12-81297c84efb1@Netapp.com> Date: Mon, 17 Apr 2017 11:57:41 -0400 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: (Resending because Google Inbox didn't switch to plain text) On 04/17/2017 11:30 AM, Olga Kornievskaia wrote: > On Mon, Apr 17, 2017 at 9:36 AM, J. Bruce Fields wrote: >> On Fri, Apr 14, 2017 at 05:22:13PM -0400, Olga Kornievskaia wrote: >>> On Fri, Apr 14, 2017 at 4:09 PM, Mora, Jorge wrote: >>>> On 4/13/17, 11:45 AM, "J. Bruce Fields" wrote: >>>>> Are you timing just the copy_file_range() call, or do you include a >>>>> following sync? >>>> >>>> I am timing right before calling copy_file_range() up to doing an fsync() and close() of the destination file. >>>> For the traditional copy is the same, I am timing right before the first read on the source file up to the >>>> fsync() and close() of the destination file. >>> >>> Why should do we need a sync after copy_file_range(). kernel >>> copy_file_range() will send the commits for any unstable copies it >>> received. >> >> Why does it do that? As far as I can tell it's not required by >> documentation for copy_file_range() or COPY. COPY has a write verifier >> and a stable_how argument in the reply. Skipping the commits would >> allow better performance in case a copy requires multiple COPY calls. >> >> But, in any case, if copy_file_range() already committed then it >> probably doesn't make a significant difference to the timing whether you >> include a following sync and/or close. > > Hm. It does make sense. Anna wrote the original code which included > the COMMIT after copy which I haven't thought about. > > Anna, any comments? I think the commit just seemed like a good idea at the time. I'm okay with changing it if it doesn't make sense. Anna > > _______________________________________________ > nfsv4 mailing list > nfsv4@ietf.org > https://www.ietf.org/mailman/listinfo/nfsv4 >