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 E2107C001DC for ; Thu, 27 Jul 2023 12:30:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232517AbjG0Ma6 (ORCPT ); Thu, 27 Jul 2023 08:30:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37134 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232656AbjG0Map (ORCPT ); Thu, 27 Jul 2023 08:30:45 -0400 Received: from out-74.mta0.migadu.com (out-74.mta0.migadu.com [IPv6:2001:41d0:1004:224b::4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 697E71AD for ; Thu, 27 Jul 2023 05:30:36 -0700 (PDT) Message-ID: <09d2ab2b-1269-21f5-7b7d-410c0f311887@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1690461034; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3PYsZ8fztDLb8zB2LbfphLlVJcGazDoAn1755qEELm0=; b=biv65rS16yG471XhUCuu9oete8E5kBm4b82GXvrRalQJTSD34AanuOZBGtnbSG3cskzWDQ uvVFdCshOGn8Hc97zP4Awlr6XLLp3a0/jLxnkv556gFWy3W0bVcqrj8O4ICuxTAGhKugT1 +XbDMDfxi+u7P+jzDfj2cwrmVZQ4Gkc= Date: Thu, 27 Jul 2023 20:30:27 +0800 MIME-Version: 1.0 Subject: Re: [RFC 0/7] io_uring lseek Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Hao Xu To: io-uring@vger.kernel.org, Jens Axboe Cc: Dominique Martinet , Pavel Begunkov , Christian Brauner , Alexander Viro , Stefan Roesch , Clay Harris , Dave Chinner , "Darrick J . Wong" , linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, Wanpeng Li References: <20230726102603.155522-1-hao.xu@linux.dev> In-Reply-To: <20230726102603.155522-1-hao.xu@linux.dev> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 7/26/23 18:25, Hao Xu wrote: > From: Hao Xu > > This series adds lseek for io_uring, the motivation to import this > syscall is in previous io_uring getdents patchset, we lack a way to > rewind the file cursor when it goes to the end of file. Another reason > is lseek is a common syscall, it's good for coding consistency when > users use io_uring as their main loop. > > Patch 1 is code clean for iomap > Patch 2 adds IOMAP_NOWAIT logic for iomap lseek > Patch 3 adds a nowait parameter to for IOMAP_NOWAIT control > Patch 4 adds llseek_nowait() for file_operations so that specific > filesystem can implement it for nowait lseek > Patch 5 adds llseek_nowait() implementation for xfs > Patch 6 adds a new vfs wrapper for io_uring use > Patch 7 is the main io_uring lseek implementation > > Note, this series depends on the previous io_uring getdents series. > > This is marked RFC since there is (at least) an issue to be discussed: > The work in this series is mainly to reslove a problem that the current > llseek() in struct file_operations doesn't have a place to deliver > nowait info, and adding an argument to it results in update for llseek > implementation of all filesystems (35 functions), so here I introduce > a new llseek_nowait() as a workaround. > > For performance, it has about 20%~30% improvement on iops. > The test program is just like the one for io_uring getdents, here is the > link to it: https://github.com/HowHsu/liburing/blob/llseek/test/lseek.c > - Each test runs about 30000 async requests/sync syscalls > - Each test runs 100 times and get the average value. > - offset is randomly generated value > - the file is a 1M all zero file > > [howeyxu@~]$ python3 run_lseek.py > test args: seek mode:SEEK_SET, offset: 334772 > Average of sync : 0.012300650000000002 > Average of iouring : 0.008528009999999999 > 30.67% > > [howeyxu@~]$ python3 run_lseek.py > test args: seek mode:SEEK_CUR, offset: 389292 > Average of sync : 0.012736129999999995 > Average of iouring : 0.00928725 > 27.08% > > [howeyxu@~]$ python3 run_lseek.py > test args: seek mode:SEEK_END, offset: 281141 > Average of sync : 0.01221595 > Average of iouring : 0.008442890000000003 > 30.89% > > [howeyxu@~]$ python3 run_lseek.py > test args: seek mode:SEEK_DATA, offset: 931103 > Average of sync : 0.015496230000000005 > Average of iouring : 0.012341509999999998 > 20.36% > > [howeyxu@~]$ python3 run_lseek.py > test args: seek mode:SEEK_HOLE, offset: 430194 > Average of sync : 0.01555663000000001 > Average of iouring : 0.012064940000000003 > 22.45% > > > Hao Xu (7): > iomap: merge iomap_seek_hole() and iomap_seek_data() > xfs: add nowait support for xfs_seek_iomap_begin() > add nowait parameter for iomap_seek() > add llseek_nowait() for struct file_operations > add llseek_nowait support for xfs > add vfs_lseek_nowait() > add lseek for io_uring > > fs/ext4/file.c | 9 ++--- > fs/gfs2/inode.c | 4 +-- > fs/iomap/seek.c | 42 ++++++----------------- > fs/read_write.c | 18 ++++++++++ > fs/xfs/xfs_file.c | 34 ++++++++++++++++--- > fs/xfs/xfs_iomap.c | 4 ++- > include/linux/fs.h | 4 +++ > include/linux/iomap.h | 6 ++-- > include/uapi/linux/io_uring.h | 1 + > io_uring/fs.c | 63 +++++++++++++++++++++++++++++++++++ > io_uring/fs.h | 3 ++ > io_uring/opdef.c | 8 +++++ > 12 files changed, 145 insertions(+), 51 deletions(-) > > > base-commit: 4a4b046082eca8ae90b654d772fccc30e9f23f4d Hi folks, I'll leave this patchset here before the io_uring getdents is merged, then come back and update this one. Thanks, Hao