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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 71079C433B4 for ; Tue, 27 Apr 2021 08:38:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4BD2D61165 for ; Tue, 27 Apr 2021 08:38:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235350AbhD0Iiv (ORCPT ); Tue, 27 Apr 2021 04:38:51 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:39562 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235257AbhD0Iil (ORCPT ); Tue, 27 Apr 2021 04:38:41 -0400 Message-Id: <20210427083724.442224402@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1619512678; h=from:from: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: references:references; bh=za9/LpdcR7YbczNQL1q4eFoq0olLXl6oLIbI/NgZucM=; b=eo3zRyjk5B8V1DenZ8SBH+rx1lpm9Oo1QK5zIet7ERyb8s9KbIp141wBE1JocbiKixuaoZ +hKCLOJrcl7tItCV0ICv9JFWenwDkQJthnQnF1VPnQounFstVGHASxWSmXh1JquiyxWM/Z lCygh9gRwqEFfeI/3k3J7PeVsW3/r+Mjc9Uwrhu64iMvTt5fzM9MPNtZFdhpLolbXFRUNX BRf0XKSn8JNJOtgB6+gaz7749cLXbtLYPTK7nwhgbXIM8Vw/r4T1Hp6bVcaK+GpXEWtmbz WWDPKY2v2XQHoIIsHrD99Dfv/zEv4AXvD4/vMvhqhQDG7Ke82ReYtjjhZGWt7w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1619512678; h=from:from: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: references:references; bh=za9/LpdcR7YbczNQL1q4eFoq0olLXl6oLIbI/NgZucM=; b=brsdFASCE5TiZLAc7vQHtmjOD5vC1UT9/lNPPZZpKu/Z056YHd0gtlLkGhtdeeXnEdpE6B p00jCRntlANPGpAA== Date: Tue, 27 Apr 2021 10:25:41 +0200 From: Thomas Gleixner To: LKML Cc: Anna-Maria Behnsen , Peter Zijlstra , Marcelo Tosatti , Frederic Weisbecker , Peter Xu , Nitesh Narayan Lal , Alex Belits , "Rafael J. Wysocki" , John Stultz Subject: [patch 4/8] timekeeping: Distangle resume and clock-was-set events References: <20210427082537.611978720@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-transfer-encoding: 8-bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Resuming timekeeping is a clock-was-set event and uses the clock-was-set notification mechanism. This is in the way of making the clock-was-set update for hrtimers selective so unnecessary IPIs are avoided when a CPU base does not have timers queued which are affected by the clock setting. Distangle it by invoking hrtimer_resume() on each unfreezing CPU and invoke the new timerfd_resume() function from timekeeping_resume() which is the only place where this is needed. Rename hrtimer_resume() to hrtimer_resume_local() to reflect the change. With this the clock_was_set*() functions are not longer required to IPI all CPUs unconditionally and can get some smarts to avoid them. Signed-off-by: Thomas Gleixner --- include/linux/hrtimer.h | 1 - kernel/time/hrtimer.c | 15 ++++++--------- kernel/time/tick-common.c | 7 +++++++ kernel/time/tick-internal.h | 2 ++ kernel/time/timekeeping.c | 4 +++- 5 files changed, 18 insertions(+), 11 deletions(-) --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -354,7 +354,6 @@ extern void timerfd_resume(void); static inline void timerfd_clock_was_set(void) { } static inline void timerfd_resume(void) { } #endif -extern void hrtimers_resume(void); DECLARE_PER_CPU(struct tick_device, tick_cpu_device); --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -914,8 +914,8 @@ static void clock_was_set_work(struct wo static DECLARE_WORK(hrtimer_work, clock_was_set_work); /* - * Called from timekeeping and resume code to reprogram the hrtimer - * interrupt device on all cpus and to notify timerfd. + * Called from timekeeping code to reprogram the hrtimer interrupt device + * on all cpus and to notify timerfd. */ void clock_was_set_delayed(void) { @@ -923,18 +923,15 @@ void clock_was_set_delayed(void) } /* - * During resume we might have to reprogram the high resolution timer - * interrupt on all online CPUs. However, all other CPUs will be - * stopped with IRQs interrupts disabled so the clock_was_set() call - * must be deferred. + * Called during resume either directly from via timekeeping_resume() + * or in the case of s2idle from tick_unfreeze() to ensure that the + * hrtimers are up to date. */ -void hrtimers_resume(void) +void hrtimers_resume_local(void) { lockdep_assert_irqs_disabled(); /* Retrigger on the local CPU */ retrigger_next_event(NULL); - /* And schedule a retrigger for all others */ - clock_was_set_delayed(); } /* --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -475,6 +475,13 @@ void tick_resume_local(void) else tick_resume_oneshot(); } + + /* + * Ensure that hrtimers are up to date and the clockevents device + * is reprogrammed correctly when high resolution timers are + * enabled. + */ + hrtimers_resume_local(); } /** --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -167,3 +167,5 @@ void timer_clear_idle(void); void clock_was_set(void); void clock_was_set_delayed(void); + +void hrtimers_resume_local(void); --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1799,8 +1799,10 @@ void timekeeping_resume(void) touch_softlockup_watchdog(); + /* Resume the clockevent device(s) and hrtimers */ tick_resume(); - hrtimers_resume(); + /* Notify timerfd as resume is equivalent to clock_was_set() */ + timerfd_resume(); } int timekeeping_suspend(void)