From nobody Mon Dec 29 04:57:35 2025 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 5F8DFC4167B for ; Fri, 1 Dec 2023 09:28:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378173AbjLAJ2a (ORCPT ); Fri, 1 Dec 2023 04:28:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41224 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378167AbjLAJ16 (ORCPT ); Fri, 1 Dec 2023 04:27:58 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 439561BD6 for ; Fri, 1 Dec 2023 01:27:24 -0800 (PST) From: Anna-Maria Behnsen DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1701422842; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IdBDR0/tYNJhJm6cSGNxPr1uzJXFKTmkB6lItnLpMig=; b=3VH7dqj99SCQxtKQ1cSHqIAwzHimk0La70Y55WoifDDH6FVLlQTD7yElldyys8j5ak6Ljq YM2qwCAcIoxkO3hle8SiRG4mhPdiNBC/EL0AwtvgMX4Kqp1sbL/KJu9cLEaFC1rpO7xrQr D42gEzHFUKk9udutpeiMZHyEuXmMHcC/OsdsNl1AYyKkSb8mRAHkzDl6n6TU3xEWUhsY3K usjBau79n5bQPwp4uEWs/boCxqsThIyOccM08vg6aBAC9p8HXqfiG9EV+O2fxtx/1XSuGd 0lItm/ND1gNEZOUCslMqCpUE3+It9I2+8K80cO721GJVXTEDDgT7kZwG9JbByA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1701422842; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IdBDR0/tYNJhJm6cSGNxPr1uzJXFKTmkB6lItnLpMig=; b=ObRXt5dMA2n4hQG6FSjAmMYBdk0L7rGzSvM/iGKlEi37gmbtj9rRCfhmDpjRCr0+YuSwYw jMbfdkMFH/57TNBQ== To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra , John Stultz , Thomas Gleixner , Eric Dumazet , "Rafael J . Wysocki" , Arjan van de Ven , "Paul E . McKenney" , Frederic Weisbecker , Rik van Riel , Steven Rostedt , Sebastian Siewior , Giovanni Gherdovich , Lukasz Luba , "Gautham R . Shenoy" , Srinivas Pandruvada , K Prateek Nayak , Anna-Maria Behnsen , Richard Cochran Subject: [PATCH v9 23/32] timers: Retrieve next expiry of pinned/non-pinned timers separately Date: Fri, 1 Dec 2023 10:26:45 +0100 Message-Id: <20231201092654.34614-24-anna-maria@linutronix.de> In-Reply-To: <20231201092654.34614-1-anna-maria@linutronix.de> References: <20231201092654.34614-1-anna-maria@linutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" For the conversion of the NOHZ timer placement to a pull at expiry time model it's required to have separate expiry times for the pinned and the non-pinned (movable) timers. Therefore struct timer_events is introduced. No functional change Originally-by: Richard Cochran (linutronix GmbH) Signed-off-by: Anna-Maria Behnsen Reviewed-by: Frederic Weisbecker --- v9: Update was required (change of preceding patches) --- kernel/time/timer.c | 35 +++++++++++++++++++++++++++++++---- 1 file changed, 31 insertions(+), 4 deletions(-) diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 366ea26ce3ba..0d53d853ae22 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -221,6 +221,11 @@ struct timer_base { =20 static DEFINE_PER_CPU(struct timer_base, timer_bases[NR_BASES]); =20 +struct timer_events { + u64 local; + u64 global; +}; + #ifdef CONFIG_NO_HZ_COMMON =20 static DEFINE_STATIC_KEY_FALSE(timers_nohz_active); @@ -1983,10 +1988,11 @@ static unsigned long next_timer_interrupt(struct ti= mer_base *base, static inline u64 __get_next_timer_interrupt(unsigned long basej, u64 base= m, bool *idle) { + struct timer_events tevt =3D { .local =3D KTIME_MAX, .global =3D KTIME_MA= X }; unsigned long nextevt, nextevt_local, nextevt_global; struct timer_base *base_local, *base_global; - u64 expires =3D KTIME_MAX; bool local_first; + u64 expires; =20 /* * Pretend that there is no timer pending if the cpu is offline. @@ -1995,7 +2001,7 @@ static inline u64 __get_next_timer_interrupt(unsigned= long basej, u64 basem, if (cpu_is_offline(smp_processor_id())) { if (idle) *idle =3D true; - return expires; + return tevt.local; } =20 base_local =3D this_cpu_ptr(&timer_bases[BASE_LOCAL]); @@ -2022,13 +2028,31 @@ static inline u64 __get_next_timer_interrupt(unsign= ed long basej, u64 basem, =20 nextevt =3D local_first ? nextevt_local : nextevt_global; =20 - if (base_local->timers_pending || base_global->timers_pending) { + /* + * If the @nextevt is at max. one tick away, use @nextevt and store + * it in the local expiry value. The next global event is irrelevant in + * this case and can be left as KTIME_MAX. + */ + if (time_before_eq(nextevt, basej + 1)) { /* If we missed a tick already, force 0 delta */ if (time_before(nextevt, basej)) nextevt =3D basej; - expires =3D basem + (u64)(nextevt - basej) * TICK_NSEC; + tevt.local =3D basem + (u64)(nextevt - basej) * TICK_NSEC; + goto unlock; } =20 + /* + * Update tevt.* values: + * + * If the local queue expires first, then the global event can be + * ignored. If the global queue is empty, nothing to do either. + */ + if (!local_first && base_global->timers_pending) + tevt.global =3D basem + (u64)(nextevt_global - basej) * TICK_NSEC; + + if (base_local->timers_pending) + tevt.local =3D basem + (u64)(nextevt_local - basej) * TICK_NSEC; + /* * We have a fresh next event. Check whether we can forward the * base. @@ -2058,9 +2082,12 @@ static inline u64 __get_next_timer_interrupt(unsigne= d long basej, u64 basem, trace_timer_base_idle(base_local->is_idle, base_local->cpu); } =20 +unlock: raw_spin_unlock(&base_global->lock); raw_spin_unlock(&base_local->lock); =20 + expires =3D min_t(u64, tevt.local, tevt.global); + return cmp_next_hrtimer_event(basem, expires); } =20 --=20 2.39.2