From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F10BCC33CB1 for ; Tue, 14 Jan 2020 15:09:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C039124681 for ; Tue, 14 Jan 2020 15:09:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729148AbgANPJE (ORCPT ); Tue, 14 Jan 2020 10:09:04 -0500 Received: from mx2.suse.de ([195.135.220.15]:55364 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728977AbgANPJE (ORCPT ); Tue, 14 Jan 2020 10:09:04 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id DE52DAD22; Tue, 14 Jan 2020 15:09:01 +0000 (UTC) Date: Tue, 14 Jan 2020 15:09:02 +0000 From: Luis Henriques To: Jeff Layton Cc: Gregory Farnum , Sage Weil , Ilya Dryomov , "Yan, Zheng" , ceph-devel , linux-kernel Subject: Re: [RFC PATCH v4] ceph: use 'copy-from2' operation in copy_file_range Message-ID: <20200114150902.GA28556@brahms.Home> References: <20200108100353.23770-1-lhenriques@suse.com> <913eb28e6bb698f27f1831f75ea5250497ee659c.camel@kernel.org> <20200114095555.GA17907@brahms.Home> <46c92e6678906fa065b18e418044647e7cdb47e1.camel@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <46c92e6678906fa065b18e418044647e7cdb47e1.camel@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 14, 2020 at 06:57:56AM -0500, Jeff Layton wrote: > On Tue, 2020-01-14 at 09:55 +0000, Luis Henriques wrote: > > On Mon, Jan 13, 2020 at 09:10:01AM -0800, Gregory Farnum wrote: > > > On Thu, Jan 9, 2020 at 5:06 AM Jeff Layton wrote: > > > > On Wed, 2020-01-08 at 10:03 +0000, Luis Henriques wrote: > > > > > Instead of using the 'copy-from' operation, switch copy_file_range to the > > > > > new 'copy-from2' operation, which allows to send the truncate_seq and > > > > > truncate_size parameters. > > > > > > > > > > If an OSD does not support the 'copy-from2' operation it will return > > > > > -EOPNOTSUPP. In that case, the kernel client will stop trying to do > > > > > remote object copies for this fs client and will always use the generic > > > > > VFS copy_file_range. > > > > > > > > > > Signed-off-by: Luis Henriques > > > > > --- > > > > > Hi Jeff, > > > > > > > > > > This is a follow-up to the discussion in [1]. Since PR [2] has been > > > > > merged, it's now time to change the kernel client to use the new > > > > > 'copy-from2'. And that's what this patch does. > > > > > > > > > > [1] https://lore.kernel.org/lkml/20191118120935.7013-1-lhenriques@suse.com/ > > > > > [2] https://github.com/ceph/ceph/pull/31728 > > > > > > > > > > fs/ceph/file.c | 13 ++++++++++++- > > > > > fs/ceph/super.c | 1 + > > > > > fs/ceph/super.h | 3 +++ > > > > > include/linux/ceph/osd_client.h | 1 + > > > > > include/linux/ceph/rados.h | 2 ++ > > > > > net/ceph/osd_client.c | 18 ++++++++++++------ > > > > > 6 files changed, 31 insertions(+), 7 deletions(-) > > > > > > > > > > diff --git a/fs/ceph/file.c b/fs/ceph/file.c > > > > > index 11929d2bb594..1e6cdf2dfe90 100644 > > > > > --- a/fs/ceph/file.c > > > > > +++ b/fs/ceph/file.c > > > > > @@ -1974,6 +1974,10 @@ static ssize_t __ceph_copy_file_range(struct file *src_file, loff_t src_off, > > > > > if (ceph_test_mount_opt(src_fsc, NOCOPYFROM)) > > > > > return -EOPNOTSUPP; > > > > > > > > > > + /* Do the OSDs support the 'copy-from2' operation? */ > > > > > + if (!src_fsc->have_copy_from2) > > > > > + return -EOPNOTSUPP; > > > > > + > > > > > /* > > > > > * Striped file layouts require that we copy partial objects, but the > > > > > * OSD copy-from operation only supports full-object copies. Limit > > > > > @@ -2101,8 +2105,15 @@ static ssize_t __ceph_copy_file_range(struct file *src_file, loff_t src_off, > > > > > CEPH_OSD_OP_FLAG_FADVISE_NOCACHE, > > > > > &dst_oid, &dst_oloc, > > > > > CEPH_OSD_OP_FLAG_FADVISE_SEQUENTIAL | > > > > > - CEPH_OSD_OP_FLAG_FADVISE_DONTNEED, 0); > > > > > + CEPH_OSD_OP_FLAG_FADVISE_DONTNEED, > > > > > + dst_ci->i_truncate_seq, dst_ci->i_truncate_size, > > > > > + CEPH_OSD_COPY_FROM_FLAG_TRUNCATE_SEQ); > > > > > if (err) { > > > > > + if (err == -EOPNOTSUPP) { > > > > > + src_fsc->have_copy_from2 = false; > > > > > + pr_notice("OSDs don't support 'copy-from2'; " > > > > > + "disabling copy_file_range\n"); > > > > > + } > > > > > dout("ceph_osdc_copy_from returned %d\n", err); > > > > > if (!ret) > > > > > ret = err; > > > > > > > > The patch itself looks fine to me. I'll not merge yet, since you sent it > > > > as an RFC, but I don't have any objection to it at first glance. The > > > > only other comment I'd make is that you should probably split this into > > > > two patches -- one for the libceph changes and one for cephfs. > > > > > > > > On a related note, I wonder if we'd get better performance out of large > > > > copy_file_range calls here if you were to move the wait for all of these > > > > osd requests after issuing them all in parallel? > > > > > > > > Currently we're doing: > > > > > > > > copy_from > > > > wait > > > > copy_from > > > > wait > > > > > > > > ...but figure that the second copy_from might very well be between osds > > > > that are not involved in the first copy. There's no reason to do them > > > > sequentially. It'd be better to issue all of the OSD requests first, and > > > > then wait on all of the replies in turn: > > > > > > If this is added (good idea in general) it should be throttled — we > > > don’t want users accidentally trying to copy a 1TB file and setting > > > off 250000 simultaneous copy_from2 requests! > > > > Good point, thanks for the input Greg. I'll have this in consideration. > > That'll probably require another kernel module knob for setting this > > throttling value. > > > > > > Yes, we probably do need some sort of limit here. It'd be nice to avoid > adding new knobs for it though. Maybe we could make this value some > multiple of min(rsize,wsize) ? Yeah, that's probably a reasonable approach. I'll see what I can come up with, once I get to it. First, /me wants to find out if this will _really_ improve performance. Cheers, -- Luís