From patchwork Fri Sep 13 13:54:15 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13803492 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id C7EDBFA3758 for ; Fri, 13 Sep 2024 13:54:41 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 98B3A6B00D7; Fri, 13 Sep 2024 09:54:40 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 915686B00D8; Fri, 13 Sep 2024 09:54:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 78DA16B00D9; Fri, 13 Sep 2024 09:54:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 57C376B00D7 for ; Fri, 13 Sep 2024 09:54:40 -0400 (EDT) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 03D4F121F6F for ; Fri, 13 Sep 2024 13:54:39 +0000 (UTC) X-FDA: 82559860320.02.45E5502 Received: from nyc.source.kernel.org (nyc.source.kernel.org [147.75.193.91]) by imf29.hostedemail.com (Postfix) with ESMTP id 4FE55120016 for ; Fri, 13 Sep 2024 13:54:38 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=s4gq5z6h; spf=pass (imf29.hostedemail.com: domain of jlayton@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=jlayton@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1726235571; h=from:from:sender: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:dkim-signature; bh=nYxI/s/zN+s+q2Nqv+AAPg+emHE8JaGmLAHYbhN/AGI=; b=TQKirYEeT2kXbV1YQ6VrgvmFITkTgGda5n05k4yLN+iy8vKkwkcDTU1+hjessUxP3Hj/TC v1yHUzwGZYEkR3Has4qdAz7GgsDnz/6SQtb9Y/QshuF4W/iKxT7EMtpfW/EvQ63jvPD6+q 3qF213ECah37oe9vOvEEful2wbxOGZw= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1726235571; a=rsa-sha256; cv=none; b=p0X+TtujCkHkNg54+ysDv+5MoODGMLWkz25KmSIGkAbaHjMer74rHGZ7Oc6eIvdQUo10SE BTzUpsa8JVODBKt9efmscOZMICoC2dsz6NcbbijKJD8CvKtuYXMvGgS0slLW6Iy5YCgmt7 m8u1TTziWdbAhBaABB+cSmLrn9HRohc= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=s4gq5z6h; spf=pass (imf29.hostedemail.com: domain of jlayton@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=jlayton@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id E60E8A447C6; Fri, 13 Sep 2024 13:54:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BF469C4CEC0; Fri, 13 Sep 2024 13:54:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1726235677; bh=KHbT8i/Qcxqnz2+0udQZ1J3l24AVjm4qbm+DkSqt5l4=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=s4gq5z6hcBvpH4Af29Xa3mpQqQYLzKD4py2xkhJFItmOHrX6Qd/Fgf6YVXRDe3MGr Y6ZtMmWbFjlzRcj4YIH5Xkc3/s3iDMH749NSTPEdbLAXKYVAyc+y0M176gv5js+3CQ sM+9flb6wNVmu5snNzxlWS3Jh0jMftXjUknTZwQMV25wcG7XoM8Unq4hH1/sr/r8sw mH/kWzpS43Xv8h79gRRUjdNRKmpwsS/AyuC+xx+pCsIl0H3CHgvLzt/mk4TvDmLOOq 6CWsCS/+/JC9Bx5hZIys1oqiaV5ujeaTgpNILKa007hMD2FDMzhYguW1uISUDErtCa 3OkcxFDgqNMtw== From: Jeff Layton Date: Fri, 13 Sep 2024 09:54:15 -0400 Subject: [PATCH v7 06/11] fs: add percpu counters for significant multigrain timestamp events MIME-Version: 1.0 Message-Id: <20240913-mgtime-v7-6-92d4020e3b00@kernel.org> References: <20240913-mgtime-v7-0-92d4020e3b00@kernel.org> In-Reply-To: <20240913-mgtime-v7-0-92d4020e3b00@kernel.org> To: John Stultz , Thomas Gleixner , Stephen Boyd , Alexander Viro , Christian Brauner , Jan Kara , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , 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 0.14.1 X-Developer-Signature: v=1; a=openpgp-sha256; l=4153; i=jlayton@kernel.org; h=from:subject:message-id; bh=KHbT8i/Qcxqnz2+0udQZ1J3l24AVjm4qbm+DkSqt5l4=; b=owEBbQKS/ZANAwAIAQAOaEEZVoIVAcsmYgBm5EQIsjChr/AGoTI8XHoboWzHgL1UrmuoBOIh2 H0F2aytFBiJAjMEAAEIAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCZuRECAAKCRAADmhBGVaC FQ/IEADDyLUPPS3+cN83808MzxZztxPDxXZD2JHsYTymxmOFO/RaD8qGe4hUZ7ZdN2LWKzMI5fr ppbNy6x0jKBcBM85ugKAyHqnvOuHlMrYzaKqj9+ANAywJslEBvAS/ukrrgESCwYCAKsVteGI+Z/ 8HQiNipXu2BjMQpbBsqqiNhIx9bvlR1ZXfFpndkgMklebePjxpZD1v65WqSD2tAQegFDYw9536b 0GVXFbwG2vTPWEFHPDs+aJcgA67VQdSvHHTTw3F5ZlfEphmYdXiBTWGeKajVsSEl7yMNcKaJL35 fs7kOeSLHIqh0fEj44Mxaxo7kAivA2UusbstCWI/Pv/lENOM5lsIcxYSZc/huctUzScUYdffl1W XAisX9gk2C5t1jEsqJBm0RZixHiU+Wq2C1JOZ60pg7b9hYl7f+M/nTslorqoL0d9U/FZg7DLqdO Dlw2uMvAA9rNutfj3ERGBr6Ko5LYiLULlICoyjDA8+1QW0zIohk7qhLyfCipFTPyTfVs1okIOIN 3+5eFy1j/B7UjGCZVH7xZH3x7QHe81R8CYRojAQWu4pk/js1aKMe7iyvy+xakmgmSyOWxU2Xp83 gJuk+plif3OX9OVu1StHpvYDsqookQd8OLqsIAqAaVzGVk0Q8HvCS5liO38Z/JS5bnukCW21eR2 8bDMmGYu8mWFbAA== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 X-Stat-Signature: szdhripjj9prg6hr1m77p4am7wmykqun X-Rspamd-Queue-Id: 4FE55120016 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1726235678-289675 X-HE-Meta: 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 LNWWBC3m GD+8GZ4f2WxZ+b0hxyBHsllIXet8bCy27/Ac1LJLR7rgKd5wTwH03pJFAFYClAFhz2iffNkJ5TtcAo/6U//VH0DAEbjm6Oi/8ldSVrmfDqY1RRW0JeRRyWiH8KKMNrqXxGpZE/JbgqCemFf5qZMHZ9gvvLSrgs84KINZqNenguscWvSku4ZpAJRNP2a7Sj6Md6kmy+1qV1+xLpqsL3LJk5A9E6bBI+Jm30IjDsmTLGSYbPyYffhuOMl+2606tQy2gv4FyBZFONT9m57zdojafArdpEzlce7+76HxXK0djQjrqtcm3Ks42swZRTA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: New percpu counters for counting various stats around mgtimes, 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 Reviewed-by: Josef Bacik Reviewed-by: Darrick J. Wong Reviewed-by: Jan Kara Signed-off-by: Jeff Layton --- fs/inode.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 72 insertions(+), 5 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index d19f70422a5d..749eb549dec5 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 +103,69 @@ long get_nr_dirty_inodes(void) return nr_dirty > 0 ? nr_dirty : 0; } +#ifdef CONFIG_DEBUG_FS +static DEFINE_PER_CPU(unsigned long, mg_ctime_updates); +static DEFINE_PER_CPU(unsigned long, mg_fine_stamps); +static DEFINE_PER_CPU(unsigned long, mg_ctime_swaps); + +static long get_mg_ctime_updates(void) +{ + int i; + long sum = 0; + + for_each_possible_cpu(i) + sum += per_cpu(mg_ctime_updates, i); + return sum < 0 ? 0 : sum; +} + +static long get_mg_fine_stamps(void) +{ + int i; + long sum = 0; + + for_each_possible_cpu(i) + sum += per_cpu(mg_fine_stamps, i); + return sum < 0 ? 0 : sum; +} + +static long get_mg_ctime_swaps(void) +{ + int i; + long sum = 0; + + for_each_possible_cpu(i) + sum += per_cpu(mg_ctime_swaps, i); + return sum < 0 ? 0 : sum; +} + +#define mgtime_counter_inc(__var) this_cpu_inc(__var) + +static int mgts_show(struct seq_file *s, void *p) +{ + long ctime_updates = get_mg_ctime_updates(); + long ctime_swaps = get_mg_ctime_swaps(); + long fine_stamps = get_mg_fine_stamps(); + + seq_printf(s, "%lu %lu %lu\n", + ctime_updates, ctime_swaps, fine_stamps); + 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 */ @@ -2650,10 +2715,9 @@ EXPORT_SYMBOL(timestamp_truncate); * * If it is multigrain, then we first see if the coarse-grained timestamp is * distinct from what we have. If so, then we'll just use that. If we have to - * get a fine-grained timestamp, then do so, and try to swap it into the floor. - * We accept the new floor value regardless of the outcome of the cmpxchg. - * After that, we try to swap the new value into i_ctime_nsec. Again, we take - * the resulting ctime, regardless of the outcome of the swap. + * get a fine-grained timestamp, then do so. After that, we try to swap the new + * value into i_ctime_nsec. We take the resulting ctime, regardless of the + * outcome of the swap. */ struct timespec64 inode_set_ctime_current(struct inode *inode) { @@ -2680,8 +2744,10 @@ struct timespec64 inode_set_ctime_current(struct inode *inode) struct timespec64 ctime = { .tv_sec = inode->i_ctime_sec, .tv_nsec = cns & ~I_CTIME_QUERIED }; - if (timespec64_compare(&now, &ctime) <= 0) + if (timespec64_compare(&now, &ctime) <= 0) { + mgtime_counter_inc(mg_fine_stamps); ktime_get_real_ts64_mg(&now, cookie); + } } now = timestamp_truncate(now, inode); @@ -2696,6 +2762,7 @@ 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?