From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e33.co.us.ibm.com (e33.co.us.ibm.com [32.97.110.151]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e33.co.us.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id B2D4B2C06DD for ; Fri, 29 Nov 2013 21:47:00 +1100 (EST) Received: from /spool/local by e33.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 29 Nov 2013 03:46:57 -0700 Received: from b03cxnp07027.gho.boulder.ibm.com (b03cxnp07027.gho.boulder.ibm.com [9.17.130.14]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id BE12A19D8045 for ; Fri, 29 Nov 2013 03:46:48 -0700 (MST) Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by b03cxnp07027.gho.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id rAT8ipUR4784580 for ; Fri, 29 Nov 2013 09:44:51 +0100 Received: from d03av01.boulder.ibm.com (localhost [127.0.0.1]) by d03av01.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id rATAkqpg016443 for ; Fri, 29 Nov 2013 03:46:54 -0700 Subject: [PATCH V4 8/9] cpuidle/ppc: Nominate new broadcast cpu on hotplug of the old To: fweisbec@gmail.com, paul.gortmaker@windriver.com, paulus@samba.org, shangw@linux.vnet.ibm.com, rjw@sisk.pl, galak@kernel.crashing.org, benh@kernel.crashing.org, 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: Fri, 29 Nov 2013 16:13:35 +0530 Message-ID: <20131129104335.651.56689.stgit@preeti.in.ibm.com> In-Reply-To: <20131129104010.651.23117.stgit@preeti.in.ibm.com> References: <20131129104010.651.23117.stgit@preeti.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On hotplug of the broadcast cpu, cancel the hrtimer queued to do broadcast and nominate a new broadcast cpu. We choose the new broadcast cpu as one of the cpus in deep idle and thus 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-powerpc-book3s.c | 22 ++++++++++++++++++++++ 3 files changed, 24 insertions(+) diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h index a6604b7..e24ebb4 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 tick_broadcast_ipi_handler(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 f0603a0..021a5c5 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -852,6 +852,7 @@ void tick_broadcast_ipi_handler(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-powerpc-book3s.c b/drivers/cpuidle/cpuidle-powerpc-book3s.c index 649c330..59cd529 100644 --- a/drivers/cpuidle/cpuidle-powerpc-book3s.c +++ b/drivers/cpuidle/cpuidle-powerpc-book3s.c @@ -288,6 +288,12 @@ static int fastsleep_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. */ @@ -366,6 +372,7 @@ static int powerpc_book3s_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); @@ -378,6 +385,21 @@ static int powerpc_book3s_cpuidle_add_cpu_notifier(struct notifier_block *n, cpuidle_resume_and_unlock(); break; + case CPU_DYING: + case CPU_DYING_FROZEN: + spin_lock_irqsave(&fastsleep_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()); + tick_broadcast(cpumask_of(bc_cpu)); + } + } + spin_unlock_irqrestore(&fastsleep_idle_lock, flags); + break; + case CPU_DEAD: case CPU_DEAD_FROZEN: cpuidle_pause_and_lock();