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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6C34C433F5 for ; Fri, 4 Mar 2022 22:13:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229731AbiCDWNu (ORCPT ); Fri, 4 Mar 2022 17:13:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51454 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229475AbiCDWNt (ORCPT ); Fri, 4 Mar 2022 17:13:49 -0500 Received: from mail104.syd.optusnet.com.au (mail104.syd.optusnet.com.au [211.29.132.246]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 10B85103F; Fri, 4 Mar 2022 14:12:59 -0800 (PST) Received: from dread.disaster.area (pa49-186-17-0.pa.vic.optusnet.com.au [49.186.17.0]) by mail104.syd.optusnet.com.au (Postfix) with ESMTPS id A7D2D52FBC4; Sat, 5 Mar 2022 09:12:56 +1100 (AEDT) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1nQGAR-001Zvp-Ep; Sat, 05 Mar 2022 09:12:55 +1100 Date: Sat, 5 Mar 2022 09:12:55 +1100 From: Dave Chinner To: Christoph Hellwig Cc: axboe@kernel.dk, sagi@grimberg.me, kbusch@kernel.org, song@kernel.org, linux-block@vger.kernel.org, linux-raid@vger.kernel.org, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 2/2] block: remove the per-bio/request write hint Message-ID: <20220304221255.GL3927073@dread.disaster.area> References: <20220304175556.407719-1-hch@lst.de> <20220304175556.407719-2-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220304175556.407719-2-hch@lst.de> X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.4 cv=deDjYVbe c=1 sm=1 tr=0 ts=62228eea a=+dVDrTVfsjPpH/ci3UuFng==:117 a=+dVDrTVfsjPpH/ci3UuFng==:17 a=kj9zAlcOel0A:10 a=o8Y5sQTvuykA:10 a=7-415B0cAAAA:8 a=pB72X_AyP2OfXCB9ywQA:9 a=CjuIK1q_8ugA:10 a=biEYGPWJfzWAr4FL6Ov7:22 Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org On Fri, Mar 04, 2022 at 06:55:56PM +0100, Christoph Hellwig wrote: > With the NVMe support for this gone, there are no consumers of these hints > left, so remove them. > > Signed-off-by: Christoph Hellwig > --- > block/bio.c | 2 -- > block/blk-crypto-fallback.c | 1 - > block/blk-merge.c | 14 -------------- > block/blk-mq-debugfs.c | 24 ------------------------ > block/blk-mq.c | 1 - > block/bounce.c | 1 - > block/fops.c | 3 --- > drivers/md/raid1.c | 2 -- > drivers/md/raid5-ppl.c | 28 +++------------------------- > drivers/md/raid5.c | 6 ------ > fs/btrfs/extent_io.c | 1 - > fs/buffer.c | 13 +++++-------- > fs/direct-io.c | 3 --- > fs/ext4/page-io.c | 5 +---- > fs/f2fs/data.c | 2 -- > fs/gfs2/lops.c | 1 - > fs/iomap/buffered-io.c | 2 -- > fs/iomap/direct-io.c | 1 - > fs/mpage.c | 1 - > fs/zonefs/super.c | 1 - > include/linux/blk_types.h | 1 - > include/linux/blkdev.h | 3 --- > 22 files changed, 9 insertions(+), 107 deletions(-) AFAICT, all the filesystem/IO path passthrough plumbing for hints is now gone, and no hardware will ever receive hints. Doesn't this mean that file_write_hint(), file->f_write_hint and iocb->ki_hint are now completely unused, too? That also means the fcntl()s for F_{G,S}ET_FILE_RW_HINT now have zero effect on IO, so should they be neutered, too? AFAICT, this patch leaves just the f2fs allocator usage of inode->i_rw_hint to select a segment to allocate from as the remaining consumer of this entire plumbing and user API. Is that used by applications anywhere, or can that be removed and so the rest of the infrastructure get removed and the fcntl()s no-op'd or -EOPNOTSUPP? Cheers, Dave. -- Dave Chinner david@fromorbit.com