From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9314A17C7C for ; Mon, 15 Jan 2024 14:38:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="YbSTa+5p"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="tgJIiLML" From: Anna-Maria Behnsen DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1705329489; 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=Fr+0oSb+AndOblwVvQzleNBKd5oIVJXXyPBNDPB6wYY=; b=YbSTa+5pAcCvS4Wu/iTQy+7Efu4QkhWpb+LdmNJp3T/95XWrgehdESVtjUbLKPcQ8dqMlU xTtHaf5bF+8GKvsYaB8Zc4mQY3fFJllBcgiuJwZJVmpMbgjbBL6lGTx55h54r4OezUZbhJ IRfBUP3Fa9GZ2DU7soBptOC0lTWKHmFgDVNIl+gktGqF+yxvkowCu4DaEYTF5aWLhwyADV rhtl+MyMqATNTeqPe6pdPEZnmoqfzEb9MOzS/vp1sBQraZjg5f3rfPf69ytEIbn8MvtVPa JfKEhZ75t3n/omQyjat4E3DSeqNK2T2SXL16Hd0hAvPIDhx+wuEz99NmmAcH4Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1705329489; 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=Fr+0oSb+AndOblwVvQzleNBKd5oIVJXXyPBNDPB6wYY=; b=tgJIiLMLs5RmyS9MgTYmslgvJZvQpm6vHXIxjarUqg90tW0RG5XhKAJ8G2UwoJYq3URsi7 On9mOU4z1EnxBhAw== 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 v10 11/20] timers: Retrieve next expiry of pinned/non-pinned timers separately Date: Mon, 15 Jan 2024 15:37:34 +0100 Message-Id: <20240115143743.27827-12-anna-maria@linutronix.de> In-Reply-To: <20240115143743.27827-1-anna-maria@linutronix.de> References: <20240115143743.27827-1-anna-maria@linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit timers separately 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 --- v10: Fix no functional change message 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 5ca831444954..f119b44e44e0 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -221,6 +221,11 @@ struct timer_base { static DEFINE_PER_CPU(struct timer_base, timer_bases[NR_BASES]); +struct timer_events { + u64 local; + u64 global; +}; + #ifdef CONFIG_NO_HZ_COMMON static DEFINE_STATIC_KEY_FALSE(timers_nohz_active); @@ -1986,10 +1991,11 @@ static unsigned long next_timer_interrupt(struct timer_base *base, static inline u64 __get_next_timer_interrupt(unsigned long basej, u64 basem, bool *idle) { + struct timer_events tevt = { .local = KTIME_MAX, .global = KTIME_MAX }; unsigned long nextevt, nextevt_local, nextevt_global; struct timer_base *base_local, *base_global; - u64 expires = KTIME_MAX; bool local_first; + u64 expires; /* * Pretend that there is no timer pending if the cpu is offline. @@ -1998,7 +2004,7 @@ static inline u64 __get_next_timer_interrupt(unsigned long basej, u64 basem, if (cpu_is_offline(smp_processor_id())) { if (idle) *idle = true; - return expires; + return tevt.local; } base_local = this_cpu_ptr(&timer_bases[BASE_LOCAL]); @@ -2014,13 +2020,32 @@ static inline u64 __get_next_timer_interrupt(unsigned long basej, u64 basem, nextevt = local_first ? nextevt_local : nextevt_global; - 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 = basej; - expires = basem + (u64)(nextevt - basej) * TICK_NSEC; + tevt.local = basem + (u64)(nextevt - basej) * TICK_NSEC; + goto forward; } + /* + * 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 = basem + (u64)(nextevt_global - basej) * TICK_NSEC; + + if (base_local->timers_pending) + tevt.local = basem + (u64)(nextevt_local - basej) * TICK_NSEC; + +forward: /* * We have a fresh next event. Check whether we can forward the * base. @@ -2051,6 +2076,8 @@ static inline u64 __get_next_timer_interrupt(unsigned long basej, u64 basem, raw_spin_unlock(&base_global->lock); raw_spin_unlock(&base_local->lock); + expires = min_t(u64, tevt.local, tevt.global); + return cmp_next_hrtimer_event(basem, expires); } -- 2.39.2