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 1F58D292B44 for ; Wed, 3 Sep 2025 20:51:22 +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=1756932683; cv=none; b=GjgQVVrXWh5zyNFXWoyl12EWcwvPUlA0EtYD0PM+NM0kcd0Y6KBfw5WgirD4DtlOwDpNm9cEWmZ2k/DIncrKmEm1VLg6nT6dt/MPeG3TnVjOC/7R7bLEAZWA88IHzP/kQ8ETaRlQ8wHItiyDdYeI49Isq5m96zNte6xLq8Wh7sU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756932683; c=relaxed/simple; bh=ktamuSk1Y4/IB41UxBZS97z4qraC8RPmBNcmSEP7XGM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=flaHKp0DytNUF/KzZge8jm2LK+qoacXMv7BgW1dnTsjq6qCi3n7KciMnTLKzb7+xWlILZq1FcpzJi3cGxMUnghyiLeppOh3oKjbL9vEgZdyx1xQwG4ArHFts8NKv4kJ4Mq6Q2tSLLVSHq6jAawg9SEo4AaIHBV91GZh95Y2B0cQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EuCZRSyg; 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="EuCZRSyg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6F073C4CEE7; Wed, 3 Sep 2025 20:51:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756932682; bh=ktamuSk1Y4/IB41UxBZS97z4qraC8RPmBNcmSEP7XGM=; h=From:To:Cc:Subject:Date:From; b=EuCZRSyg8Hs1QJf40Fu+ZnQ35evJr2bR4Sh/VaeZH6kGlaYojrRPL2YnIcvWK+6ZF n8GyNINCUpHVjFAy8H/DfveIj+QRJWULw+8KFN4TFiBkBQQ+AyZiNc3L/jlUvQZMK3 VXdHd3pCMIdjfWUq+9sqwct/3fAdZLvhjOBWGuZUE+3mNPq0VLyTmgYRm4c68PhilC CTbzP6pJ7MfzY2ejNmID+G2QwC0zfQAvedkUdEjWqDq7THrF683sMHb5pN/CWEennt H95nlPPrSCLSToqij4xz1IkDGVtLvBbPREb5EUZouLFbOphDxBiP70UnZvFUo/iXKq r+pBxTPrmtegw== From: Mike Snitzer To: Chuck Lever , Jeff Layton Cc: linux-nfs@vger.kernel.org Subject: [PATCH v9 0/9] NFSD: add "NFSD DIRECT" and "NFSD DONTCACHE" IO modes Date: Wed, 3 Sep 2025 16:51:12 -0400 Message-ID: <20250903205121.41380-1-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. This code has proven to work well during my testing. Any suggestions for further refinement are welcome. Thanks, Mike Changes since v8: - Remove a few WARN_ON_ONCE from the misaligned DIO READ and WRITE paths - pr_warn_ratelimited if EINVAL on misaligned READ and WRITE paths - handle DIO WRITE -ENOTBLK return by falling back to using buffered IO. - fix misaligned DIO READ to not use a start_extra_page - use /end/ of rq_pages for front_pad page - fix checkpatch warning about 'unsigned' in nfsd_iov_iter_aligned_bvec - fix NFSD debugfs interfaces to no longer use UNSPECIFIED state, explicitly default to NFSD_IO_BUFFERED - add Documentation/filesystems/nfs/nfsd-io-modes.rst Mike Snitzer (9): 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: issue READs using O_DIRECT even if IO is misaligned NFSD: issue WRITEs using O_DIRECT even if IO is misaligned NFSD: add nfsd_analyze_read_dio and nfsd_analyze_write_dio trace events NFSD: add Documentation/filesystems/nfs/nfsd-io-modes.rst NFSD: use /end/ of rq_pages for misaligned DIO READ's start_extra page .../filesystems/nfs/nfsd-io-modes.rst | 144 ++++++ fs/nfsd/debugfs.c | 98 +++++ fs/nfsd/filecache.c | 32 ++ fs/nfsd/filecache.h | 4 + fs/nfsd/nfs4xdr.c | 8 +- fs/nfsd/nfsd.h | 10 + fs/nfsd/nfsfh.c | 4 + fs/nfsd/trace.h | 61 +++ fs/nfsd/vfs.c | 409 +++++++++++++++++- fs/nfsd/vfs.h | 2 +- include/linux/sunrpc/svc.h | 5 +- 11 files changed, 759 insertions(+), 18 deletions(-) create mode 100644 Documentation/filesystems/nfs/nfsd-io-modes.rst -- 2.44.0