From patchwork Mon Feb 14 10:45:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Bristot de Oliveira X-Patchwork-Id: 12745449 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 29B9BC433FE for ; Mon, 14 Feb 2022 11:24:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350973AbiBNLYO convert rfc822-to-8bit (ORCPT ); Mon, 14 Feb 2022 06:24:14 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:51456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350958AbiBNLXv (ORCPT ); Mon, 14 Feb 2022 06:23:51 -0500 Received: from us-smtp-delivery-44.mimecast.com (us-smtp-delivery-44.mimecast.com [207.211.30.44]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 43BBD723C2 for ; Mon, 14 Feb 2022 02:59:11 -0800 (PST) Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-637-FLtZyrvGNYCv9PgvGY4JhA-1; Mon, 14 Feb 2022 05:47:59 -0500 X-MC-Unique: FLtZyrvGNYCv9PgvGY4JhA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E9769801B0E; Mon, 14 Feb 2022 10:47:56 +0000 (UTC) Received: from x1.com (unknown [10.22.16.130]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5948926E7E; Mon, 14 Feb 2022 10:47:51 +0000 (UTC) From: Daniel Bristot de Oliveira To: Steven Rostedt Cc: Daniel Bristot de Oliveira , Jonathan Corbet , Ingo Molnar , Thomas Gleixner , Peter Zijlstra , Will Deacon , Catalin Marinas , Marco Elver , Dmitry Vyukov , "Paul E. McKenney" , Shuah Khan , Gabriele Paoloni , Juri Lelli , Clark Williams , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-devel@vger.kernel.org, Wim Van Sebroeck , Guenter Roeck Subject: [RFC V2 17/21] watchdog/dev: Add tracepoints Date: Mon, 14 Feb 2022 11:45:08 +0100 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=bristot@kernel.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org Add a set of tracepoints, enabling the observability of the watchdog device interactions with user-space. The events are: watchdog:watchdog_open watchdog:watchdog_close watchdog:watchdog_start watchdog:watchdog_stop watchdog:watchdog_set_timeout watchdog:watchdog_ping watchdog:watchdog_nowayout watchdog:watchdog_set_keep_alive watchdog:watchdog_keep_alive Cc: Wim Van Sebroeck Cc: Guenter Roeck Cc: Jonathan Corbet Cc: Steven Rostedt Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Will Deacon Cc: Catalin Marinas Cc: Marco Elver Cc: Dmitry Vyukov Cc: "Paul E. McKenney" Cc: Shuah Khan Cc: Gabriele Paoloni Cc: Juri Lelli Cc: Clark Williams Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira --- drivers/watchdog/watchdog_dev.c | 41 ++++++++++++- include/linux/watchdog.h | 7 +-- include/trace/events/watchdog.h | 103 ++++++++++++++++++++++++++++++++ 3 files changed, 142 insertions(+), 9 deletions(-) create mode 100644 include/trace/events/watchdog.h diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c index 3a3d8b5c7ad5..0beeac5d4541 100644 --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -44,6 +44,9 @@ #include /* For watchdog specific items */ #include /* For copy_to_user/put_user/... */ +#define CREATE_TRACE_POINTS +#include + #include "watchdog_core.h" #include "watchdog_pretimeout.h" @@ -130,9 +133,11 @@ static inline void watchdog_update_worker(struct watchdog_device *wdd) if (watchdog_need_worker(wdd)) { ktime_t t = watchdog_next_keepalive(wdd); - if (t > 0) + if (t > 0) { hrtimer_start(&wd_data->timer, t, HRTIMER_MODE_REL_HARD); + trace_watchdog_set_keep_alive(wdd, ktime_to_ms(t)); + } } else { hrtimer_cancel(&wd_data->timer); } @@ -149,14 +154,16 @@ static int __watchdog_ping(struct watchdog_device *wdd) now = ktime_get(); if (ktime_after(earliest_keepalive, now)) { - hrtimer_start(&wd_data->timer, - ktime_sub(earliest_keepalive, now), + ktime_t t = ktime_sub(earliest_keepalive, now); + hrtimer_start(&wd_data->timer, t, HRTIMER_MODE_REL_HARD); + trace_watchdog_set_keep_alive(wdd, ktime_to_ms(t)); return 0; } wd_data->last_hw_keepalive = now; + trace_watchdog_ping(wdd); if (wdd->ops->ping) err = wdd->ops->ping(wdd); /* ping the watchdog */ else @@ -215,6 +222,7 @@ static void watchdog_ping_work(struct kthread_work *work) wd_data = container_of(work, struct watchdog_core_data, work); mutex_lock(&wd_data->lock); + trace_watchdog_keep_alive(wd_data->wdd); if (watchdog_worker_should_ping(wd_data)) __watchdog_ping(wd_data->wdd); mutex_unlock(&wd_data->lock); @@ -252,6 +260,8 @@ static int watchdog_start(struct watchdog_device *wdd) set_bit(_WDOG_KEEPALIVE, &wd_data->status); + trace_watchdog_start(wdd); + started_at = ktime_get(); if (watchdog_hw_running(wdd) && wdd->ops->ping) { err = __watchdog_ping(wdd); @@ -298,6 +308,7 @@ static int watchdog_stop(struct watchdog_device *wdd) return -EBUSY; } + trace_watchdog_stop(wdd); if (wdd->ops->stop) { clear_bit(WDOG_HW_RUNNING, &wdd->status); err = wdd->ops->stop(wdd); @@ -370,6 +381,7 @@ static int watchdog_set_timeout(struct watchdog_device *wdd, if (watchdog_timeout_invalid(wdd, timeout)) return -EINVAL; + trace_watchdog_set_timeout(wdd, timeout); if (wdd->ops->set_timeout) { err = wdd->ops->set_timeout(wdd, timeout); } else { @@ -432,6 +444,23 @@ static int watchdog_get_timeleft(struct watchdog_device *wdd, return 0; } +/* + * watchdog_set_nowayout - set nowaout bit + * @wdd: The watchdog device to set nowayoutbit + * @nowayout A boolean on/off switcher + * + * If nowayout boolean is true, the nowayout option is set. No action is + * taken if nowayout is false. + */ +void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout) +{ + if (nowayout) { + set_bit(WDOG_NO_WAY_OUT, &wdd->status); + trace_watchdog_nowayout(wdd); + } +} +EXPORT_SYMBOL(watchdog_set_nowayout); + #ifdef CONFIG_WATCHDOG_SYSFS static ssize_t nowayout_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -457,6 +486,7 @@ static ssize_t nowayout_store(struct device *dev, struct device_attribute *attr, /* nowayout cannot be disabled once set */ if (test_bit(WDOG_NO_WAY_OUT, &wdd->status) && !value) return -EPERM; + watchdog_set_nowayout(wdd, value); return len; } @@ -858,6 +888,8 @@ static int watchdog_open(struct inode *inode, struct file *file) goto out_clear; } + trace_watchdog_open(wdd); + err = watchdog_start(wdd); if (err < 0) goto out_mod; @@ -880,6 +912,7 @@ static int watchdog_open(struct inode *inode, struct file *file) return stream_open(inode, file); out_mod: + trace_watchdog_close(wdd); module_put(wd_data->wdd->ops->owner); out_clear: clear_bit(_WDOG_DEV_OPEN, &wd_data->status); @@ -940,6 +973,7 @@ static int watchdog_release(struct inode *inode, struct file *file) /* make sure that /dev/watchdog can be re-opened */ clear_bit(_WDOG_DEV_OPEN, &wd_data->status); + trace_watchdog_close(wdd); done: running = wdd && watchdog_hw_running(wdd); mutex_unlock(&wd_data->lock); @@ -952,6 +986,7 @@ static int watchdog_release(struct inode *inode, struct file *file) module_put(wd_data->cdev.owner); put_device(&wd_data->dev); } + return 0; } diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h index 99660197a36c..11d93407e492 100644 --- a/include/linux/watchdog.h +++ b/include/linux/watchdog.h @@ -139,12 +139,7 @@ static inline bool watchdog_hw_running(struct watchdog_device *wdd) return test_bit(WDOG_HW_RUNNING, &wdd->status); } -/* Use the following function to set the nowayout feature */ -static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout) -{ - if (nowayout) - set_bit(WDOG_NO_WAY_OUT, &wdd->status); -} +void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout); /* Use the following function to stop the watchdog on reboot */ static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd) diff --git a/include/trace/events/watchdog.h b/include/trace/events/watchdog.h new file mode 100644 index 000000000000..5d5617ab611a --- /dev/null +++ b/include/trace/events/watchdog.h @@ -0,0 +1,103 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM watchdog + +#if !defined(_TRACE_WATCHDOG_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_WATCHDOG_H + +#include + +DECLARE_EVENT_CLASS(dev_operations_template, + + TP_PROTO(struct watchdog_device *wdd), + + TP_ARGS(wdd), + + TP_STRUCT__entry( + __field(__u32, id) + ), + + TP_fast_assign( + __entry->id = wdd->id; + ), + + TP_printk("id=%d", + __entry->id) +); + +/* + * Add a comment + */ +DEFINE_EVENT(dev_operations_template, watchdog_open, + TP_PROTO(struct watchdog_device *wdd), + TP_ARGS(wdd)); + +DEFINE_EVENT(dev_operations_template, watchdog_close, + TP_PROTO(struct watchdog_device *wdd), + TP_ARGS(wdd)); + +DEFINE_EVENT(dev_operations_template, watchdog_start, + TP_PROTO(struct watchdog_device *wdd), + TP_ARGS(wdd)); + +DEFINE_EVENT(dev_operations_template, watchdog_stop, + TP_PROTO(struct watchdog_device *wdd), + TP_ARGS(wdd)); + +DEFINE_EVENT(dev_operations_template, watchdog_ping, + TP_PROTO(struct watchdog_device *wdd), + TP_ARGS(wdd)); + +DEFINE_EVENT(dev_operations_template, watchdog_keep_alive, + TP_PROTO(struct watchdog_device *wdd), + TP_ARGS(wdd)); + +DEFINE_EVENT(dev_operations_template, watchdog_nowayout, + TP_PROTO(struct watchdog_device *wdd), + TP_ARGS(wdd)); + + +TRACE_EVENT(watchdog_set_timeout, + + TP_PROTO(struct watchdog_device *wdd, u64 timeout), + + TP_ARGS(wdd, timeout), + + TP_STRUCT__entry( + __field(__u32, id) + __field(__u64, timeout) + ), + + TP_fast_assign( + __entry->id = wdd->id; + __entry->timeout = timeout; + ), + + TP_printk("id=%d timeout=%llus", + __entry->id, __entry->timeout) +); + +TRACE_EVENT(watchdog_set_keep_alive, + + TP_PROTO(struct watchdog_device *wdd, u64 timeout), + + TP_ARGS(wdd, timeout), + + TP_STRUCT__entry( + __field(__u32, id) + __field(__u64, timeout) + ), + + TP_fast_assign( + __entry->id = wdd->id; + __entry->timeout = timeout; + ), + + TP_printk("id=%d keep_alive=%llums", + __entry->id, __entry->timeout) +); + +#endif /* _TRACE_WATCHDOG_H */ + +/* This part must be outside protection */ +#include