From patchwork Wed Sep 11 02:52:26 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Preeti U Murthy X-Patchwork-Id: 274106 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id 961732C0AEF for ; Wed, 11 Sep 2013 12:57:56 +1000 (EST) Received: from e8.ny.us.ibm.com (e8.ny.us.ibm.com [32.97.182.138]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e8.ny.us.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id BB1892C0627 for ; Wed, 11 Sep 2013 12:55:19 +1000 (EST) Received: from /spool/local by e8.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 11 Sep 2013 03:55:16 +0100 Received: from d01dlp03.pok.ibm.com (9.56.250.168) by e8.ny.us.ibm.com (192.168.1.108) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Wed, 11 Sep 2013 03:55:13 +0100 Received: from b01cxnp22033.gho.pok.ibm.com (b01cxnp22033.gho.pok.ibm.com [9.57.198.23]) by d01dlp03.pok.ibm.com (Postfix) with ESMTP id C4B73C90041 for ; Tue, 10 Sep 2013 22:55:12 -0400 (EDT) Received: from d01av05.pok.ibm.com (d01av05.pok.ibm.com [9.56.224.195]) by b01cxnp22033.gho.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r8B2tCjk48693292 for ; Wed, 11 Sep 2013 02:55:13 GMT Received: from d01av05.pok.ibm.com (loopback [127.0.0.1]) by d01av05.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r8B2t949026699 for ; Tue, 10 Sep 2013 22:55:12 -0400 Received: from preeti.in.ibm.com (preeti.in.ibm.com [9.124.35.218]) by d01av05.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id r8B2t2q4026119; Tue, 10 Sep 2013 22:55:02 -0400 Subject: [PATCH V3 6/6] cpuidle/ppc: Nominate new broadcast cpu on hotplug of the old To: benh@kernel.crashing.org, paul.gortmaker@windriver.com, paulus@samba.org, shangw@linux.vnet.ibm.com, rjw@sisk.pl, galak@kernel.crashing.org, fweisbec@gmail.com, paulmck@linux.vnet.ibm.com, arnd@arndb.de, linux-pm@vger.kernel.org, rostedt@goodmis.org, michael@ellerman.id.au, john.stultz@linaro.org, tglx@linutronix.de, chenhui.zhao@freescale.com, deepthi@linux.vnet.ibm.com, r58472@freescale.com, geoff@infradead.org, linux-kernel@vger.kernel.org, srivatsa.bhat@linux.vnet.ibm.com, schwidefsky@de.ibm.com, svaidy@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org From: Preeti U Murthy Date: Wed, 11 Sep 2013 08:22:26 +0530 Message-ID: <20130911025226.27726.71053.stgit@preeti.in.ibm.com> In-Reply-To: <20130911024906.27726.4735.stgit@preeti.in.ibm.com> References: <20130911024906.27726.4735.stgit@preeti.in.ibm.com> User-Agent: StGit/0.16-38-g167d MIME-Version: 1.0 X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13091102-0320-0000-0000-000000F56C5D X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.16rc2 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" On hotplug of the broadcast cpu, cancel the hrtimer queued to do broadcast and nominate a new broadcast cpu to be the first cpu in the broadcast mask which includes all the cpus that have notified the broadcast framework about entering deep idle state. Since the new broadcast cpu is one of the cpus in deep idle, send an ipi to wake it up to continue the duty of broadcast. The new broadcast cpu needs to find out if it woke up to resume broadcast. If so it needs to restart the broadcast hrtimer on itself. Its possible that the old broadcast cpu was hotplugged out when the broadcast hrtimer was about to fire on it. Therefore the newly nominated broadcast cpu should set the broadcast hrtimer on itself to expire immediately so as to not miss wakeups under such scenarios. Signed-off-by: Preeti U Murthy --- arch/powerpc/include/asm/time.h | 1 + arch/powerpc/kernel/time.c | 1 + drivers/cpuidle/cpuidle-ibm-power.c | 22 ++++++++++++++++++++++ 3 files changed, 24 insertions(+) diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h index 38341fa..3bc0205 100644 --- a/arch/powerpc/include/asm/time.h +++ b/arch/powerpc/include/asm/time.h @@ -31,6 +31,7 @@ struct rtc_time; extern void to_tm(int tim, struct rtc_time * tm); extern void GregorianDay(struct rtc_time *tm); extern void decrementer_timer_interrupt(void); +extern void broadcast_irq_entry(void); extern void generic_calibrate_decr(void); diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 44a76de..0ac2e11 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -853,6 +853,7 @@ void decrementer_timer_interrupt(void) { u64 *next_tb = &__get_cpu_var(decrementers_next_tb); + broadcast_irq_entry(); *next_tb = get_tb_or_rtc(); __timer_interrupt(); } diff --git a/drivers/cpuidle/cpuidle-ibm-power.c b/drivers/cpuidle/cpuidle-ibm-power.c index ae47a0a..580ea04 100644 --- a/drivers/cpuidle/cpuidle-ibm-power.c +++ b/drivers/cpuidle/cpuidle-ibm-power.c @@ -282,6 +282,12 @@ static int longnap_loop(struct cpuidle_device *dev, return index; } +void broadcast_irq_entry(void) +{ + if (smp_processor_id() == bc_cpu) + hrtimer_start(bc_hrtimer, ns_to_ktime(0), HRTIMER_MODE_REL_PINNED); +} + /* * States for dedicated partition case. */ @@ -360,6 +366,7 @@ static int power_cpuidle_add_cpu_notifier(struct notifier_block *n, unsigned long action, void *hcpu) { int hotcpu = (unsigned long)hcpu; + unsigned long flags; struct cpuidle_device *dev = per_cpu(cpuidle_devices, hotcpu); @@ -372,6 +379,21 @@ static int power_cpuidle_add_cpu_notifier(struct notifier_block *n, cpuidle_resume_and_unlock(); break; + case CPU_DYING: + case CPU_DYING_FROZEN: + spin_lock_irqsave(&longnap_idle_lock, flags); + if (hotcpu == bc_cpu) { + bc_cpu = -1; + hrtimer_cancel(bc_hrtimer); + if (!cpumask_empty(tick_get_broadcast_oneshot_mask())) { + bc_cpu = cpumask_first( + tick_get_broadcast_oneshot_mask()); + arch_send_tick_broadcast(cpumask_of(bc_cpu)); + } + } + spin_unlock_irqrestore(&longnap_idle_lock, flags); + break; + case CPU_DEAD: case CPU_DEAD_FROZEN: cpuidle_pause_and_lock();