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 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 F2326C07E95 for ; Tue, 13 Jul 2021 13:54:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB1A1601FE for ; Tue, 13 Jul 2021 13:54:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236809AbhGMN5c (ORCPT ); Tue, 13 Jul 2021 09:57:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236741AbhGMN5V (ORCPT ); Tue, 13 Jul 2021 09:57:21 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2A73FC0613E9 for ; Tue, 13 Jul 2021 06:54:31 -0700 (PDT) Message-Id: <20210713135158.488853478@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1626184469; 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=7w/WjmY4L1WiRcb0h50YeGNn764ly9SO0FIXZqbq/0o=; b=JKZJ5CpgtLipWXMrXni4KP6hA6jYA+iOFak49JelSN1ovRLNSdPxrCMhAuGAS0FscG+kIX 0S2dNdu4MdaXV1fs65v5IyxoIgSNkkdZ2MwZk+xTdeVpfJgcM1UMm6dJ1MK7YD2nQyMMX4 MIxUqhCUcUX9FaJEoEXrMIwdGvtGttgvsnn9/Odpfc6j4dInaIWbzl0hWmIM5sTnOR5P7q wwXm6Kn82LxK7Oye6MRBk9vE+qU38XqV0JIJ7XhjYS/Y2d4lOa/y0Ok018RW0pt9cJxRV4 L107tGkJLL090ISXCEuopfH30Sf5sT6fxe75SbD9wsSRG6MhtpV2cxv53HlFnw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1626184469; 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=7w/WjmY4L1WiRcb0h50YeGNn764ly9SO0FIXZqbq/0o=; b=/LoNft1dinzXOXxXjMrIgV9KSTOGvyPFKQr0Vrmog65oY7rt0JqocgnHjHzzYBWXfi9Hrp H9+i/zd+P9zjVlDg== Date: Tue, 13 Jul 2021 15:39:51 +0200 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Anna-Maria Behnsen , Marcelo Tosatti , Frederic Weisbecker Subject: [patch V2 06/10] timekeeping: Distangle resume and clock-was-set events References: <20210713133945.063650594@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 From: Thomas Gleixner 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 @@ -900,8 +900,8 @@ 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) { @@ -909,18 +909,15 @@ 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 @@ -470,6 +470,13 @@ 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 @@ -168,3 +168,5 @@ 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 @@ -1810,8 +1810,10 @@ 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)