From nobody Tue Dec 16 13:54:33 2025 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 29FE23D571 for ; Wed, 21 Feb 2024 09:06:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708506381; cv=none; b=DvHS4KkkQGOQk9DySHMpkZPaU5ilabeKSQ7v2HReqyMnt49OQ0qsVpm7Loqi2UXHucrh5Eeckjdc9lHZaTRdoTDCvwl/xWFt6LjrwDfkBmKzk0CAPstGnsOQ7HiVtR5+s3KQvPbOqJArbw72UbEfmln2Z/wdVLkfEy5YxBVrHFk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708506381; c=relaxed/simple; bh=8GAi+clf4ARudGxl8gQObKgEbjDfootfzyMlgIma4rc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=a9VrJItPEUE3KtO3MbcvcnDQCyIgBUQverrB/H3Oh1B47dCxXD1pL3qDspTVKRmU26p+hvs2VhUmxoGmGloeEpSJZ8NGHAgLLbAeXSocYhlI5mWkcphAdCcNPs9M80F6YRmaqJcgOWSum9swo+XEBfaPOWEACvctc+pZ7Nhk7YE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=u/sfdH+V; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=XuF4oFDy; arc=none smtp.client-ip=193.142.43.55 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="u/sfdH+V"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="XuF4oFDy" From: Anna-Maria Behnsen DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1708506373; 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=1b+XJv886jQpeQSImvPTzFbojcDlDb9MA0gl6E6c3yw=; b=u/sfdH+Vk7kDr9sz2nE4bHm9dCTIDU49w4pS88q+ts5uf4fH8H8L9lFaZKNsBGTLXHGi4h hybiBIpDkjFGsxd4qda7fWnmJI+X+iXI57e8SZuQLSi3CmfUOOG3YVFR4fLuuPnY/+NS5t gQRuFX6tmxSkPo7r3+mNyY2jYx++aL4c0HR3fMRakftpGMhYBEyDtgNXkNOv7r6zIY2yw6 OzpFoq8EkguASNq+nF9MCLb99IVzQGss52yziACJ2/PBf2KFR+Ofipqo0NdkkdezWFen/Y avz7QIbHo0Cql5QN2efQi+T78JUUfSGIofpmOE6QXb0D0KqLoXFGEc2Q3O91nA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1708506373; 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=1b+XJv886jQpeQSImvPTzFbojcDlDb9MA0gl6E6c3yw=; b=XuF4oFDy234l2NaSKHRP6EJO2dzYvZlOG2UwL/ppCrMgrcelmBfVunKnh0A+OOesZY0xda UM3Qf53oKdQpfkBw== 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 , Christian Loehle , Anna-Maria Behnsen Subject: [PATCH v11 12/20] timers: Split out "get next timer interrupt" functionality Date: Wed, 21 Feb 2024 10:05:40 +0100 Message-Id: <20240221090548.36600-13-anna-maria@linutronix.de> In-Reply-To: <20240221090548.36600-1-anna-maria@linutronix.de> References: <20240221090548.36600-1-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: quoted-printable Content-Type: text/plain; charset="utf-8" The functionality for getting the next timer interrupt in get_next_timer_interrupt() is split into a separate function fetch_next_timer_interrupt() to be usable by other call sites. This is preparatory work for the conversion of the NOHZ timer placement to a pull at expiry time model. No functional change. Signed-off-by: Anna-Maria Behnsen Reviewed-by: Frederic Weisbecker --- v10: Update was required (change of preceding patches) v9: Update was required (change of preceding patches) v6: s/splitted/split v5: Update commit message v4: Fix typo in comment --- kernel/time/timer.c | 64 +++++++++++++++++++++++++++------------------ 1 file changed, 38 insertions(+), 26 deletions(-) diff --git a/kernel/time/timer.c b/kernel/time/timer.c index f119b44e44e0..9fa759dd80f5 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1988,30 +1988,13 @@ static unsigned long next_timer_interrupt(struct ti= mer_base *base, return base->next_expiry; } =20 -static inline u64 __get_next_timer_interrupt(unsigned long basej, u64 base= m, - bool *idle) +static unsigned long fetch_next_timer_interrupt(unsigned long basej, u64 b= asem, + struct timer_base *base_local, + struct timer_base *base_global, + struct timer_events *tevt) { - 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; bool local_first; - u64 expires; - - /* - * Pretend that there is no timer pending if the cpu is offline. - * Possible pending timers will be migrated later to an active cpu. - */ - if (cpu_is_offline(smp_processor_id())) { - if (idle) - *idle =3D true; - return tevt.local; - } - - base_local =3D this_cpu_ptr(&timer_bases[BASE_LOCAL]); - base_global =3D this_cpu_ptr(&timer_bases[BASE_GLOBAL]); - - raw_spin_lock(&base_local->lock); - raw_spin_lock_nested(&base_global->lock, SINGLE_DEPTH_NESTING); =20 nextevt_local =3D next_timer_interrupt(base_local, basej); nextevt_global =3D next_timer_interrupt(base_global, basej); @@ -2029,8 +2012,8 @@ static inline u64 __get_next_timer_interrupt(unsigned= long basej, u64 basem, /* If we missed a tick already, force 0 delta */ if (time_before(nextevt, basej)) nextevt =3D basej; - tevt.local =3D basem + (u64)(nextevt - basej) * TICK_NSEC; - goto forward; + tevt->local =3D basem + (u64)(nextevt - basej) * TICK_NSEC; + return nextevt; } =20 /* @@ -2040,12 +2023,41 @@ static inline u64 __get_next_timer_interrupt(unsign= ed long basej, u64 basem, * 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; + tevt->global =3D basem + (u64)(nextevt_global - basej) * TICK_NSEC; =20 if (base_local->timers_pending) - tevt.local =3D basem + (u64)(nextevt_local - basej) * TICK_NSEC; + tevt->local =3D basem + (u64)(nextevt_local - basej) * TICK_NSEC; + + return nextevt; +} + +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 }; + struct timer_base *base_local, *base_global; + unsigned long nextevt; + u64 expires; + + /* + * Pretend that there is no timer pending if the cpu is offline. + * Possible pending timers will be migrated later to an active cpu. + */ + if (cpu_is_offline(smp_processor_id())) { + if (idle) + *idle =3D true; + return tevt.local; + } + + base_local =3D this_cpu_ptr(&timer_bases[BASE_LOCAL]); + base_global =3D this_cpu_ptr(&timer_bases[BASE_GLOBAL]); + + raw_spin_lock(&base_local->lock); + raw_spin_lock_nested(&base_global->lock, SINGLE_DEPTH_NESTING); + + nextevt =3D fetch_next_timer_interrupt(basej, basem, base_local, + base_global, &tevt); =20 -forward: /* * We have a fresh next event. Check whether we can forward the * base. --=20 2.39.2