From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7801C6369E for ; Wed, 18 Nov 2020 03:37:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B69D24695 for ; Wed, 18 Nov 2020 03:37:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="OhY4HjIO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727257AbgKRDgv (ORCPT ); Tue, 17 Nov 2020 22:36:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51382 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726682AbgKRDgu (ORCPT ); Tue, 17 Nov 2020 22:36:50 -0500 Received: from mail-pl1-x643.google.com (mail-pl1-x643.google.com [IPv6:2607:f8b0:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC9A7C0613D4 for ; Tue, 17 Nov 2020 19:36:50 -0800 (PST) Received: by mail-pl1-x643.google.com with SMTP id 18so229186pli.13 for ; Tue, 17 Nov 2020 19:36:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=e9Ihw2Y+18TzSgtmb4OigPm+7MU3ujpbKP16lGjOfj8=; b=OhY4HjIOZ+0lTiFOatEbWyzN+3hQo+8XRSkU9MfUqJXie9mhDQVnUe+NuzmVwn2UV2 +IwoEflE28VZx2lSwsNtvFar4eHNheGRp58rAl8LZioo6mtVsE1YER68qK58WgYSmxWO Ra9CVB0z5A0o3gogZuiyAfOIpnPXCoYsBWtmfAJr4XZc43DWR/4Vaaww5khyVzrtQFdU vA3lmszaquZnMjv3cZLcvO8SCfJbV1bji+Rr4/0P46u4WFve0N7nuzoJE/5lia4tiygf 24/HhQbqKdggfuE4fXB2QCDHXmtURaqCuHZPrO8oNK4tI2nkRY2QP+dgiiGfii67ZWfr x56A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=e9Ihw2Y+18TzSgtmb4OigPm+7MU3ujpbKP16lGjOfj8=; b=KAaC1dlzJi/VoaRt/GCXmky081yB4g/thrkfw4avQ5aOoxVNXi0tonltQiS1jv1yrn L/uGbfUNfOMGjLOz3ENCOoBiF0pLnUDL41L1MbrRYvA9OX4kBBTWbTl1uXufdKFpUS99 23tqUZZoPXC4p/gQDouV13T7BZdlLaZr6ifOnu/PV6utlwAcSwslXO3tKvz6vmlwkpMb QrpgXWmejBbKcy/G+q9OaOSWVrsVcp1F0JlGivmARk41vFrU9DfL55XGG6lCfdQmJfDU dIcPT+WIYvhV9RzAdWyJZLgawVAkW8KYbbaRVd0JxAM7uxzermO/t0KkiAh/FKRc99Zn rF+g== X-Gm-Message-State: AOAM532YFTWC1KQyANIzLvaXWdCLbpwArERwYlFwOhhXXP3TX5q/2uzz M4fK+RwNd1uUxLKB9/BPxTDG1WxcDg== X-Google-Smtp-Source: ABdhPJymDMEi5GYeLqbLmW7LlSMQERi8xY2hau+mlS5vC+sfpAYnpiGOFtR9uhbQXJ1FDbgR/cYIbA== X-Received: by 2002:a17:90a:df93:: with SMTP id p19mr2310006pjv.170.1605670610183; Tue, 17 Nov 2020 19:36:50 -0800 (PST) Received: from mylaptop.redhat.com ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id s21sm8915450pgm.65.2020.11.17.19.36.46 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 17 Nov 2020 19:36:49 -0800 (PST) From: Pingfan Liu To: linux-kernel@vger.kernel.org Cc: Pingfan Liu , Thomas Gleixner , Jisheng Zhang , "Peter Zijlstra (Intel)" , Vlastimil Babka , Andrew Morton , "Guilherme G. Piccoli" , Petr Mladek , kexec@lists.infradead.org Subject: [PATCH 2/3] kernel/watchdog: make watchdog_touch_ts more accurate by using nanosecond Date: Wed, 18 Nov 2020 11:36:17 +0800 Message-Id: <1605670578-23681-3-git-send-email-kernelfans@gmail.com> X-Mailer: git-send-email 2.7.5 In-Reply-To: <1605670578-23681-1-git-send-email-kernelfans@gmail.com> References: <87tuueftou.fsf@nanos.tec.linutronix.de> <1605670578-23681-1-git-send-email-kernelfans@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The incoming statistics of irq average number will base on the delta of watchdog_touch_ts. Improving the accuracy of watchdog_touch_ts from second to nanosecond can help improve the accuracy of the statistics. Signed-off-by: Pingfan Liu Cc: Thomas Gleixner Cc: Jisheng Zhang Cc: "Peter Zijlstra (Intel)" Cc: Vlastimil Babka Cc: Andrew Morton Cc: "Guilherme G. Piccoli" Cc: Petr Mladek Cc: kexec@lists.infradead.org To: linux-kernel@vger.kernel.org --- kernel/watchdog.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 5abb5b2..1cc619a 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -207,7 +207,7 @@ static void __lockup_detector_cleanup(void); * the thresholds with a factor: we make the soft threshold twice the amount of * time the hard threshold is. */ -static int get_softlockup_thresh(void) +static unsigned int get_softlockup_thresh(void) { return watchdog_thresh * 2; } @@ -217,9 +217,9 @@ static int get_softlockup_thresh(void) * resolution, and we don't need to waste time with a big divide when * 2^30ns == 1.074s. */ -static unsigned long get_timestamp(void) +static unsigned long convert_seconds(unsigned long ns) { - return running_clock() >> 30LL; /* 2^30 ~= 10^9 */ + return ns >> 30LL; /* 2^30 ~= 10^9 */ } static void set_sample_period(void) @@ -238,7 +238,7 @@ static void set_sample_period(void) /* Commands for resetting the watchdog */ static void __touch_watchdog(void) { - __this_cpu_write(watchdog_touch_ts, get_timestamp()); + __this_cpu_write(watchdog_touch_ts, running_clock()); } /** @@ -289,14 +289,15 @@ void touch_softlockup_watchdog_sync(void) __this_cpu_write(watchdog_touch_ts, SOFTLOCKUP_RESET); } -static int is_softlockup(unsigned long touch_ts) +static unsigned long is_softlockup(unsigned long touch_ts) { - unsigned long now = get_timestamp(); + unsigned long span, now = running_clock(); + span = now - touch_ts; if ((watchdog_enabled & SOFT_WATCHDOG_ENABLED) && watchdog_thresh){ /* Warn about unreasonable delays. */ - if (time_after(now, touch_ts + get_softlockup_thresh())) - return now - touch_ts; + if (time_after(convert_seconds(span), (unsigned long)get_softlockup_thresh())) + return span; } return 0; } @@ -340,9 +341,8 @@ static int softlockup_fn(void *data) /* watchdog kicker functions */ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) { - unsigned long touch_ts = __this_cpu_read(watchdog_touch_ts); + unsigned long duration, touch_ts = __this_cpu_read(watchdog_touch_ts); struct pt_regs *regs = get_irq_regs(); - int duration; int softlockup_all_cpu_backtrace = sysctl_softlockup_all_cpu_backtrace; if (!watchdog_enabled) @@ -410,7 +410,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) } pr_emerg("BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n", - smp_processor_id(), duration, + smp_processor_id(), (unsigned int)convert_seconds(duration), current->comm, task_pid_nr(current)); print_modules(); print_irqtrace_events(current); -- 2.7.5