From patchwork Wed Oct 2 21:27:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13820453 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 1A7D62178ED; Wed, 2 Oct 2024 21:27:50 +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=1727904471; cv=none; b=vDK7ptKrJkEvgp+zGvklJxdztqbnk4V6NG4hAX2GF/Eq0VKlTCBQ7GRJV6GRyswk+pXYs8G5E92ifNg5Q2UymXnqd/7WcIDwvvqFmB/Q4Zw1xebA8UPiDPvyCYH4IJKmoOEaA4BgHfWtlbamIe38Y76Z5LSsOQ68nAOjW2SB+14= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727904471; c=relaxed/simple; bh=Z8ARvNSJ2qaGQw9gXXGsklzintCaz0parTyIMYimjOU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=dTcDlVkxG5lrmLzsYS8EUfu7d5KbzExWtk6H94LWffDH7Ty1WA7L8lg4WZE1At232b6kQONQTuc5c2UKnxyQDC6BdPLT7VPVXPlWQ+N9sSUZeTHEHKERt6muX4P4SQAMlqcXNxYfcCvHu87lKAeF3KWrgflvoFu7dmIxkiiELJ4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tzCXJ6wf; 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="tzCXJ6wf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17306C4CED1; Wed, 2 Oct 2024 21:27:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727904470; bh=Z8ARvNSJ2qaGQw9gXXGsklzintCaz0parTyIMYimjOU=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=tzCXJ6wfC5VMb2ExRKKrzQ20m0/cMA8alt1mx22BM50xuDhE0GS9gVEFsrjSveh5f HFH5VS9B24S84IqvZUpSgC0C1q24ouXK3xTB7RbQfG8UaeRZcICfAK6HDjmfFkfBV7 3aO9o2M1mNeM3mDVEnXkN4uh72RWd1d3J5IlhvmQyO4+hhMRETQlHKR4X9G6/DFhRe YSYJkbBlozjLOXMmaq1m2Gt9EFtR/FJhOO+7ql9Vva32Q75BFsiORHAqNQJqujNmqW SBn90QVLpNFHTeIS+z4r+VmFCXvrhebJ9B4yq9M8D2P5LJh1lY5wtzoECPs6IH+MI2 QP5O6BUQzp8Rg== From: Jeff Layton Date: Wed, 02 Oct 2024 17:27:22 -0400 Subject: [PATCH v10 07/12] fs: add percpu counters for significant multigrain timestamp events Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241002-mgtime-v10-7-d1c4717f5284@kernel.org> References: <20241002-mgtime-v10-0-d1c4717f5284@kernel.org> In-Reply-To: <20241002-mgtime-v10-0-d1c4717f5284@kernel.org> To: John Stultz , Thomas Gleixner , Stephen Boyd , Alexander Viro , Christian Brauner , Jan Kara , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Randy Dunlap , Chandan Babu R , "Darrick J. Wong" , Theodore Ts'o , Andreas Dilger , Chris Mason , Josef Bacik , David Sterba , Hugh Dickins , Andrew Morton , Chuck Lever , Vadim Fedorenko Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-mm@kvack.org, Jeff Layton X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=3654; i=jlayton@kernel.org; h=from:subject:message-id; bh=Z8ARvNSJ2qaGQw9gXXGsklzintCaz0parTyIMYimjOU=; b=owEBbQKS/ZANAwAIAQAOaEEZVoIVAcsmYgBm/bq/TMaGYuw/cJFUuusrG5sD9Gz0d9qf6qw5y upmhOuFiF6JAjMEAAEIAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCZv26vwAKCRAADmhBGVaC FRvxD/9evDrf3HGvYTuhxkxutkxIEi68sVhkiNZD69Mm7WZA2CzmHFpkbIzJUXlNfytAPvjdSGx Se9Non3XuQRLNglgc0lhxcfcZdu/X+u5yMiBvHkBZEf5lodGBnhBUeXjm4jg9rEign2Xcke0uen zmW17gVIHwMZ3pm48WdgDnI8LGujnHwyRtaKHMgoMO1zgnVvcxwJwwUnejPgDLsmruCTvs+3DcO Y1qi5xwXYC30GgA8xLI3gOheiXnZPH7tbEJ+CH8lRjel+ECcxNYyb4BgLgnjumPTmVu+ctbB3O/ NyFL+R7Pi0fN4SNBqZmhwLTUJrcqb7DCkLXIHsvJwkrbW3Bqnf24X7QYDnJtEJQ9zSf7lLcSU6k V+ew1hvKLd2wb+drV/Ii7HSHdlUZvaWrk8oHWdjSCKLvUAmjwdajzx9wmNWqXhGfXmTr0ecFsKA NXFHfSfVYvzOmgE53f2k3i5mgVRZyIhHJUlyjRFJKFGzUxYaTAIh5NNmXRgDtW4ppFtQH53Hxhu kp4ZqjZv2oO3ibhlxc5JK1fBHr6GVEm5y/b+JdsECtsh3oy/dqkLWdOAHXM5vNLGLzaBO7Qa7Ds CYD7TxCxZPUyWMagc0FhPLEfyvMm79Aw6QZdmp6UVnPQO6c8VRfeyGOyuivKJVQaMeSbXMaQuV2 JHDiBQHJy0omjwA== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 New percpu counters for counting various stats around multigrain timestamp events, and a new debugfs file for displaying them when CONFIG_DEBUG_FS is enabled: - number of attempted ctime updates - number of successful i_ctime_nsec swaps - number of fine-grained timestamp fetches - number of floor value swap events Reviewed-by: Josef Bacik Reviewed-by: Darrick J. Wong Reviewed-by: Jan Kara Tested-by: Randy Dunlap # documentation bits Signed-off-by: Jeff Layton --- fs/inode.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) diff --git a/fs/inode.c b/fs/inode.c index f7a25c511d6b7069fa235135cf3bad0cda32815b..6d501c7308aefcbb8001d64cb46e57f1839b8a3b 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -21,6 +21,8 @@ #include #include #include +#include +#include #include #define CREATE_TRACE_POINTS #include @@ -101,6 +103,70 @@ long get_nr_dirty_inodes(void) return nr_dirty > 0 ? nr_dirty : 0; } +#ifdef CONFIG_DEBUG_FS +static DEFINE_PER_CPU(long, mg_ctime_updates); +static DEFINE_PER_CPU(long, mg_fine_stamps); +static DEFINE_PER_CPU(long, mg_ctime_swaps); + +static unsigned long get_mg_ctime_updates(void) +{ + unsigned long sum = 0; + int i; + + for_each_possible_cpu(i) + sum += data_race(per_cpu(mg_ctime_updates, i)); + return sum; +} + +static unsigned long get_mg_fine_stamps(void) +{ + unsigned long sum = 0; + int i; + + for_each_possible_cpu(i) + sum += data_race(per_cpu(mg_fine_stamps, i)); + return sum; +} + +static unsigned long get_mg_ctime_swaps(void) +{ + unsigned long sum = 0; + int i; + + for_each_possible_cpu(i) + sum += data_race(per_cpu(mg_ctime_swaps, i)); + return sum; +} + +#define mgtime_counter_inc(__var) this_cpu_inc(__var) + +static int mgts_show(struct seq_file *s, void *p) +{ + unsigned long ctime_updates = get_mg_ctime_updates(); + unsigned long ctime_swaps = get_mg_ctime_swaps(); + unsigned long fine_stamps = get_mg_fine_stamps(); + unsigned long floor_swaps = timekeeping_get_mg_floor_swaps(); + + seq_printf(s, "%lu %lu %lu %lu\n", + ctime_updates, ctime_swaps, fine_stamps, floor_swaps); + return 0; +} + +DEFINE_SHOW_ATTRIBUTE(mgts); + +static int __init mg_debugfs_init(void) +{ + debugfs_create_file("multigrain_timestamps", S_IFREG | S_IRUGO, NULL, NULL, &mgts_fops); + return 0; +} +late_initcall(mg_debugfs_init); + +#else /* ! CONFIG_DEBUG_FS */ + +#define mgtime_counter_inc(__var) do { } while (0) + +#endif /* CONFIG_DEBUG_FS */ + /* * Handle nr_inode sysctl */ @@ -2689,8 +2755,10 @@ struct timespec64 inode_set_ctime_current(struct inode *inode) if (timespec64_compare(&now, &ctime) <= 0) { ktime_get_real_ts64_mg(&now); now = timestamp_truncate(now, inode); + mgtime_counter_inc(mg_fine_stamps); } } + mgtime_counter_inc(mg_ctime_updates); /* No need to cmpxchg if it's exactly the same */ if (cns == now.tv_nsec && inode->i_ctime_sec == now.tv_sec) { @@ -2704,6 +2772,7 @@ struct timespec64 inode_set_ctime_current(struct inode *inode) /* If swap occurred, then we're (mostly) done */ inode->i_ctime_sec = now.tv_sec; trace_ctime_ns_xchg(inode, cns, now.tv_nsec, cur); + mgtime_counter_inc(mg_ctime_swaps); } else { /* * Was the change due to someone marking the old ctime QUERIED?