From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 04C1C2EE28B for ; Thu, 24 Jul 2025 19:31:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753385464; cv=none; b=tJX7fEKOoWTVzuMOW2DZUhMxnZeikmPDUa1eB3Yl3qr8b4IvbkcfiCvyEO1XicDvfVzPK7M8Ggnvc7m17qwa1dWSBK6qpl8ElCy/eUe+KOz+ZnH/Di7Yyrbv6QyXkrmiStOooUrz7rocoIWXCFQVruYKPFP9GueNSvm6Btiag0Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753385464; c=relaxed/simple; bh=VEK70GT4K1VNFIJD4RuPK2bQQ7LPAZKySVJu6PqeTg0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=WqZ9LZt2KN5PUmQTCzPtEODQJQ61zJcc+VVWB8UyqQaD1Dq4NcgOoKk9vVSzSZfb7PdeFO0Wrh8Duo9pYABjw9RW6EkkaZUGsyrxaZfYpZUt+gRja/AGQSd/LeXQjc4lOmb194dIRNXO5Eb0c29CWjk3GH3vhu3QdP62fDAulIU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JDRtJZAw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JDRtJZAw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 46F94C4CEED; Thu, 24 Jul 2025 19:31:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753385463; bh=VEK70GT4K1VNFIJD4RuPK2bQQ7LPAZKySVJu6PqeTg0=; h=From:To:Cc:Subject:Date:From; b=JDRtJZAwDnkGzougq9gmPSZARl3zZHNnIoSq2xTYgq0+8+LzMsZJg1d3Vc8vkJw9a vbURDdKaHmzifcXShtyTo+6XoR/csoHKD0VmpL13KGmol0huoGjEoNoS8TenNcT6aj LhdtkgUYaeQ6F1MIBkdMjL5h0MGSZsTgLEbQQ4D6UMQaiBtfsvzNZl2E/SzbeoVhmq C57jHC/7zNUKav5KLkEayjFPzbql9z/BezWcfrFUvG0QLbSvMCw9EGyQAC8exeUVRr mKpoL8faX4J0UubmWPK/wtM2eC4/UxOePna6IZxGxEgup/Ep1ZBRx2zfJcA94nVYTT 1wTo39j+qDqDw== From: Mike Snitzer To: Chuck Lever , Jeff Layton , Trond Myklebust , Anna Schumaker Cc: linux-nfs@vger.kernel.org Subject: [PATCH v5 00/13] NFSD DIRECT and NFS DIRECT Date: Thu, 24 Jul 2025 15:30:49 -0400 Message-ID: <20250724193102.65111-1-snitzer@kernel.org> X-Mailer: git-send-email 2.44.0 Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi, Some workloads benefit from NFSD avoiding the page cache, particularly those with a working set that is significantly larger than available system memory. This patchset introduces _optional_ support to configure the use of O_DIRECT or DONTCACHE for NFSD's READ and WRITE support. The NFSD default to use page cache is left unchanged. The performance win associated with using NFSD DIRECT was previously summarized here: https://lore.kernel.org/linux-nfs/aEslwqa9iMeZjjlV@kernel.org/ This picture offers a nice summary of performance gains: https://original.art/NFSD_direct_vs_buffered_IO.jpg Similarly, NFS and LOCALIO in particular also benefit from avoiding the page cache for workloads that have a working set that is significantly larger than available system memory. Enter: NFS DIRECT, which makes it possible to always enable LOCALIO to use O_DIRECT even if the IO is not DIO-aligned. For this v5 I've combined the NFSD and NFSD patchsets because the NFS changes do depend on the the NFSD changes. In addition, I think it makes sense to review/test these changes together. I'm sharing these again now, soon after posting the NFSD and NFS updates, to hopefully make it clear where the code stands. Thanks to Chuck's feedback I have kept the patch "NFSD: issue READs using O_DIRECT even if IO is misaligned" (and will now finish NFSD's misaligned WRITE handling, splitting IO to misaligned head and/or tail and DIO-aligned middle, and will include in the next version of this patchset -- probably mid next week). New changes in this v5: - Combine NFSD DIRECT and NFS DIRECT patches into single patchset. - Fix a "nsfd" typo in a variable of the NFSD io_cache_read patch that was masked because the later " NFSD: issue READs using O_DIRECT even if IO is misaligned" patch fixed it. - Properly include the "NFSD: filecache: only get DIO alignment attrs if NFSD_IO_DIRECT enabled" in the patch series. - Optimize NFS DIRECT's misaligned READ and WRITE support to return early if IO irreparably misaligned or already DIO-aligned. Thanks, Mike Mike Snitzer (13): NFSD: filecache: add STATX_DIOALIGN and STATX_DIO_READ_ALIGN support NFSD: pass nfsd_file to nfsd_iter_read() NFSD: add io_cache_read controls to debugfs interface NFSD: add io_cache_write controls to debugfs interface NFSD: filecache: only get DIO alignment attrs if NFSD_IO_DIRECT enabled NFSD: issue READs using O_DIRECT even if IO is misaligned nfs/localio: avoid bouncing LOCALIO if nfs_client_is_local() nfs/localio: make trace_nfs_local_open_fh more useful nfs/localio: add nfsd_file_dio_alignment nfs/localio: refactor iocb initialization nfs/localio: fallback to NFSD for misaligned O_DIRECT READs nfs/direct: add misaligned READ handling nfs/direct: add misaligned WRITE handling fs/nfs/direct.c | 262 +++++++++++++++++++++++-- fs/nfs/flexfilelayout/flexfilelayout.c | 1 + fs/nfs/internal.h | 17 +- fs/nfs/localio.c | 231 ++++++++++++++-------- fs/nfs/nfstrace.h | 47 ++++- fs/nfs/pagelist.c | 22 ++- fs/nfsd/debugfs.c | 102 ++++++++++ fs/nfsd/filecache.c | 36 ++++ fs/nfsd/filecache.h | 4 + fs/nfsd/localio.c | 11 ++ fs/nfsd/nfs4xdr.c | 8 +- fs/nfsd/nfsd.h | 10 + fs/nfsd/nfsfh.c | 4 + fs/nfsd/trace.h | 37 ++++ fs/nfsd/vfs.c | 200 +++++++++++++++++-- fs/nfsd/vfs.h | 2 +- include/linux/nfs_page.h | 1 + include/linux/nfslocalio.h | 2 + include/linux/sunrpc/svc.h | 5 +- 19 files changed, 875 insertions(+), 127 deletions(-) -- 2.44.0