From patchwork Tue Oct 1 10:59:01 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13817780 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 0D67CCE7D0D for ; Tue, 1 Oct 2024 10:59:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8EDC2280077; Tue, 1 Oct 2024 06:59:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 876A5280068; Tue, 1 Oct 2024 06:59:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6A36C280077; Tue, 1 Oct 2024 06:59:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 3BF67280068 for ; Tue, 1 Oct 2024 06:59:33 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id E1D7CA103C for ; Tue, 1 Oct 2024 10:59:32 +0000 (UTC) X-FDA: 82624737384.13.26A67A6 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf30.hostedemail.com (Postfix) with ESMTP id 2527080015 for ; Tue, 1 Oct 2024 10:59:30 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=B5NsA4Y3; spf=pass (imf30.hostedemail.com: domain of jlayton@kernel.org designates 139.178.84.217 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=1727780245; 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=j23ea2oSLHwO3VCXd7879q5pR6SW3LD6xwMWmsgaaeA=; b=AXDdvzvXCBjg7d4B4idZ18tjhrS1GIMwRP4OvDSfnKGHyvYtEAvKC8mbrZ6lBwJIkscZa8 +lpCKshwm3QJ56flQKAQTqrS7s+86KCyBETq+nfn0ASVydQyK1xHgb85fZmltxy5cSaqPQ 4I2u6aNSAv2izFjfHQ2bRjnzHME928s= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1727780245; a=rsa-sha256; cv=none; b=EPRX6ogQb6W10M8mkaQcoQiscy6Hxs7nMbBGjYJtC9XqAADbNJ8SylSsqAkK1frTaDxJJh rpXF+yFuGiv3VH12RUrhLpI6YEZZjyEe1cPqBuBClROe/qWVbOhImC+WQ3Z0UR/6cTMk7W 8X0SINvUMbid8z45oPuU+a/zRIzj2XM= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=B5NsA4Y3; spf=pass (imf30.hostedemail.com: domain of jlayton@kernel.org designates 139.178.84.217 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 dfw.source.kernel.org (Postfix) with ESMTP id 3C8C95C488B; Tue, 1 Oct 2024 10:59:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6ECCCC4CECE; Tue, 1 Oct 2024 10:59:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727780370; bh=JL2gW+C3kDxbRAGj0jMp5iB8JHuDuhS4rvTtieX78oY=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=B5NsA4Y3xe03GSebvPrrYvgPoGZbnw6mZTFF2+mbaE21jaWD0FJgt1XHCPTAvrT79 vPgqIbRwjLzaOimrju2AKsv/b/gSgB/4RSN0bLwKzrtHXHaDqtAnXqCJO2jpq2RqmX X6wO1EBN+PbuMQ86TBeql6QF8WTGyZ5Z00YdTsluw0mp4xGe3a07TAoeUMe6v2oxQv nVlXaK0ssXyss4VOzkZpjy37wUHfRBGsBv4J2GUWKNvzUSzUOk8cj7BRdZFIKFS+aJ vlLE50z3y5Llg/g8PlVvgDXTNVTBWwx4haJ2pHrfwkMGwuWWBl6P4sGfxxbpzF0K6U VFKXOjSzzaz3Q== From: Jeff Layton Date: Tue, 01 Oct 2024 06:59:01 -0400 Subject: [PATCH v8 07/12] timekeeping: add percpu counter for tracking floor swap events MIME-Version: 1.0 Message-Id: <20241001-mgtime-v8-7-903343d91bc3@kernel.org> References: <20241001-mgtime-v8-0-903343d91bc3@kernel.org> In-Reply-To: <20241001-mgtime-v8-0-903343d91bc3@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 0.14.1 X-Developer-Signature: v=1; a=openpgp-sha256; l=4015; i=jlayton@kernel.org; h=from:subject:message-id; bh=JL2gW+C3kDxbRAGj0jMp5iB8JHuDuhS4rvTtieX78oY=; b=owEBbQKS/ZANAwAIAQAOaEEZVoIVAcsmYgBm+9X6x1c8e9tak6oUEGlf0VU1qI9Vs0dKdL9Nd tgbNV9wo0aJAjMEAAEIAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCZvvV+gAKCRAADmhBGVaC Fc1QD/9eMcfRLjkeM4PSq5q9wbdZwKH0ZnxF0our+6FybuPq3dyRBmPN35tLdFGBtPY7yqdWFwS Rs/LS0WNRMUDhr1mdiuuzBDAl87afaQm6m0Ss/fKkpUFhmk/6FI30AQA1Y6CGK6rBPZYvpRMd+t xgQ8SEf51BB4aQuerAYSVbDxfIaQqxooQW4UxsVhihhRpZSz79bvs9BpfTRl7CbRAPptD7zgobF R7mUD1bo7p1UmgGdLuhyprr+Jx7N7pdA9YQpQ08sy/92KZ+vcdGFCcsOkuq10gXYaRdVyf/PRfC rRDl9JHOqi1KNQBD9zb4sWygsFJGWWPQ2CW9bYimEWy0wCKUZoEouWvbzEq4spMhwAoFngdHDsS Bz0hFemqy9Xm0kWfhA2Nfr2napvBTjUBhmHeTbT55Nfpt1HF/UZUInHDF9AdCKxXHuQ+vQSgAhY zjBXOOKmI6/5Qt1tfZh/5yUgcInlYWTFh5JfBEPO8heF5DaWba7euvt0rMdn7cjfKd4yUuyR29s oxz6la25xBwO/N9eJtho78xkfye21spBGiN+rs91RekoH21kMmErBfxm5wrhx2AsEg1f8GUUDnQ DlZ8agBEXLchtmo9h03ROpDuc/ljD3laUG05Nf9rBOcUWDcUaN4Fh4A5/crNSXCfsrkG2Taaleh he48A3qyAV/DzSQ== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 X-Rspamd-Queue-Id: 2527080015 X-Stat-Signature: 5qtowfdm6y3su9bc9jcxhd7txc49xxcf X-Rspamd-Server: rspam09 X-Rspam-User: X-HE-Tag: 1727780370-69904 X-HE-Meta: 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 mLXrkG3W 4TTBdYY7Ia9lvYu/stp9a4/9DWn9xh38VAJee55DXacnQLo9agZLJBIORnnMDow1FRN2pIOuQD+YOsDq+130AHY1Y/A1wMgbmiVxtDDF42uiNM8+gzAo1sHJiiW7wZOjh2hAXcOqy82z88bMt3uVb2IsbnO9/XASM1wj0O/+1OTNwush20swxsoGbSaKmox8q7maBkR0PPpCohUNwdIuT6TbcFBOToM8p+jpcAvtw6V39Lbj0H7itC43kjh8Fc4YCFpkjxfzafQqdlw0GhzOJsoapdVTohCftU3ZThM/ulxgR6gDPp2CetwOzjg== 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: The mgtime_floor value is a global variable for tracking the latest fine-grained timestamp handed out. Because it's a global, track the number of times that a new floor value is assigned. Add a new percpu counter to the timekeeping code to track the number of floor swap events that have occurred. Display that as a fourth integer in /sys/kernel/debug/multigrain_timestamps. Tested-by: Randy Dunlap # documentation bits Signed-off-by: Jeff Layton --- fs/inode.c | 5 +++-- include/linux/timekeeping.h | 1 + kernel/time/timekeeping.c | 1 + kernel/time/timekeeping_debug.c | 13 +++++++++++++ kernel/time/timekeeping_internal.h | 9 +++++++++ 5 files changed, 27 insertions(+), 2 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index e46f7170851b..93a9365cc22d 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -145,9 +145,10 @@ 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\n", - ctime_updates, ctime_swaps, fine_stamps); + seq_printf(s, "%lu %lu %lu %lu\n", + ctime_updates, ctime_swaps, fine_stamps, floor_swaps); return 0; } diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index 7aa85246c183..84a035e86ac8 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -48,6 +48,7 @@ extern void ktime_get_coarse_real_ts64(struct timespec64 *ts); /* Multigrain timestamp interfaces */ extern void ktime_get_coarse_real_ts64_mg(struct timespec64 *ts); extern void ktime_get_real_ts64_mg(struct timespec64 *ts); +extern unsigned long timekeeping_get_mg_floor_swaps(void); void getboottime64(struct timespec64 *ts); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 37004a4758cf..c8a934c1c8aa 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -2478,6 +2478,7 @@ void ktime_get_real_ts64_mg(struct timespec64 *ts) if (atomic64_try_cmpxchg(&mg_floor, &old, mono)) { ts->tv_nsec = 0; timespec64_add_ns(ts, nsecs); + timekeeping_inc_mg_floor_swaps(); } else { /* * Something has changed mg_floor since "old" was diff --git a/kernel/time/timekeeping_debug.c b/kernel/time/timekeeping_debug.c index b73e8850e58d..b731621ad811 100644 --- a/kernel/time/timekeeping_debug.c +++ b/kernel/time/timekeeping_debug.c @@ -17,6 +17,9 @@ #define NUM_BINS 32 +/* incremented every time mg_floor is updated */ +DEFINE_PER_CPU(unsigned long, timekeeping_mg_floor_swaps); + static unsigned int sleep_time_bin[NUM_BINS] = {0}; static int tk_debug_sleep_time_show(struct seq_file *s, void *data) @@ -53,3 +56,13 @@ void tk_debug_account_sleep_time(const struct timespec64 *t) (s64)t->tv_sec, t->tv_nsec / NSEC_PER_MSEC); } +unsigned long timekeeping_get_mg_floor_swaps(void) +{ + int i; + unsigned long sum = 0; + + for_each_possible_cpu(i) + sum += per_cpu(timekeeping_mg_floor_swaps, i); + return sum < 0 ? 0 : sum; +} + diff --git a/kernel/time/timekeeping_internal.h b/kernel/time/timekeeping_internal.h index 4ca2787d1642..f53e76d5ee7c 100644 --- a/kernel/time/timekeeping_internal.h +++ b/kernel/time/timekeeping_internal.h @@ -10,9 +10,18 @@ * timekeeping debug functions */ #ifdef CONFIG_DEBUG_FS +DECLARE_PER_CPU(unsigned long, timekeeping_mg_floor_swaps); +static inline void timekeeping_inc_mg_floor_swaps(void) +{ + this_cpu_inc(timekeeping_mg_floor_swaps); +} + extern void tk_debug_account_sleep_time(const struct timespec64 *t); #else #define tk_debug_account_sleep_time(x) +static inline void timekeeping_inc_mg_floor_swaps(void) +{ +} #endif #ifdef CONFIG_CLOCKSOURCE_VALIDATE_LAST_CYCLE