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 1AA47225A24 for ; Tue, 9 Sep 2025 19:05:27 +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=1757444728; cv=none; b=ZRfXf4KBpzkKNtVoKtM7ObfFOUkdG6lATpmCvaempIBvlUHJvT7CjnXJYXEhUf/r2XkHB41WlkwBBqXKryZlZkJVBHilpKJo0CphV6FqnhHlHUPHKay37wY+wNRpEbt5mN96dLF9+5GSb7uz4u0uiP4jwkeYX/UAvEcY+Bj6+pM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757444728; c=relaxed/simple; bh=OLQwAE8DTOJRcHiRarW7yEAjtwQqPNcxybneaiuqrCE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=nlgXuW0Fn8MeFtcWF8GwCyV7Re/3NHN8PrhkjpP7hhSOM7KGu/iLTpSyg88T96xxTdHxhgKejaBOi9vC0+xF/AL5cvM7RPH7tiDxwy/8jAUO5d9c1ZNTwo5s8VL2Yd9Bq/YxLYdmsO4bAlE+h0TB+o/SC6wV4e2+5DziVXjAG2U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uApB2Hh8; 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="uApB2Hh8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 204A3C4CEF4; Tue, 9 Sep 2025 19:05:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757444727; bh=OLQwAE8DTOJRcHiRarW7yEAjtwQqPNcxybneaiuqrCE=; h=From:To:Cc:Subject:Date:From; b=uApB2Hh8cfBmbYfYBUAGW3c8zFtWUKcnF5PrM8KxO8cGyinACGhgN7iwTGPlLA7Ba ONdln0wjzZW7d6YeTvyGkcI1TLZCAj8KVW9yJpGiHgVkpT6TZTwDn0ClVvxXmAjeTp 1+ARswNZGTSVL6WROQ6pEVnxINz5rhgsrlOj7ZJgO2s0ddHHXhKNuzy/C4ItwGNm/p Jr+9QbBvzXaucsTrig8lnr1LEjaRTxOG0nw4lvYFG+iBqeQm61gTyTGiqRbBZSGeVi QT7MZ8r7MtMdOuJvINDEtN2rp6WhhEdFgSSnANJoJ2hs6aJsH8NQgHs2ggipAJBHQn eJ+rH2oSYAWNQ== From: Chuck Lever To: NeilBrown , Jeff Layton , Olga Kornievskaia , Dai Ngo , Tom Talpey Cc: , Chuck Lever Subject: [PATCH v1 0/3] NFSD direct I/O read Date: Tue, 9 Sep 2025 15:05:22 -0400 Message-ID: <20250909190525.7214-1-cel@kernel.org> X-Mailer: git-send-email 2.50.0 Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Chuck Lever This series replaces patches 1, 2, and 5 in Mike's v9 series: https://lore.kernel.org/linux-nfs/20250903205121.41380-1-snitzer@kernel.org/T/#t Changes from Mike's v9: * The LOC introduced by the feature has been reduced considerably. * A new trace point in nfsd_file_getattr reports each file's dio alignment parameters when it is opened. * The direct I/O path has been taken out-of-line so that it may continue to be modified and optimized without perturbing the more commonly used I/O paths. * When an exported file system does not implement direct I/O, more commonly used modes are employed instead to avoid returning EOPNOTSUPP unexpectedly. * When NFSD_IO_DIRECT is selected, NFS READs of all sizes use direct I/O to provide better experimental data about small I/O workloads. I haven't found any issues with NFSv3, NFSv4.0, and NFSv4.1 tested on TCP and RDMA while /sys/kernel/debug/nfsd/io_cache_read is set to 2. Trace points confirm that NFSD is using direct I/O. The goal is to get the experimental read-side direct I/O implementation merged sooner, as the write side has a few gray areas that still need discussion and resolution. Chuck Lever (1): NFSD: Implement NFSD_IO_DIRECT for NFS READ Mike Snitzer (2): NFSD: filecache: add STATX_DIOALIGN and STATX_DIO_READ_ALIGN support NFSD: pass nfsd_file to nfsd_iter_read() fs/nfsd/debugfs.c | 2 + fs/nfsd/filecache.c | 34 +++++++++++++++++ fs/nfsd/filecache.h | 4 ++ fs/nfsd/nfs4xdr.c | 8 ++-- fs/nfsd/nfsd.h | 1 + fs/nfsd/nfsfh.c | 4 ++ fs/nfsd/trace.h | 28 ++++++++++++++ fs/nfsd/vfs.c | 85 +++++++++++++++++++++++++++++++++++++++-- fs/nfsd/vfs.h | 2 +- include/trace/misc/fs.h | 22 +++++++++++ 10 files changed, 182 insertions(+), 8 deletions(-) -- 2.50.0