Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756157Ab1FGQ35 (ORCPT ); Tue, 7 Jun 2011 12:29:57 -0400 Received: from e23smtp08.au.ibm.com ([202.81.31.141]:34072 "EHLO e23smtp08.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753040Ab1FGQ34 (ORCPT ); Tue, 7 Jun 2011 12:29:56 -0400 From: Trinabh Gupta Subject: [RFC PATCH V1 3/7] cpuidle: stop using pm_idle To: linux-pm@lists.linux-foundation.org, linuxppc-dev@ozlabs.org Cc: linux-kernel@vger.kernel.org Date: Tue, 07 Jun 2011 21:59:50 +0530 Message-ID: <20110607162947.6848.79430.stgit@tringupt.in.ibm.com> In-Reply-To: <20110607162847.6848.44707.stgit@tringupt.in.ibm.com> References: <20110607162847.6848.44707.stgit@tringupt.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7046 Lines: 252 From: Len Brown pm_idle does not scale as an idle handler registration mechanism. Don't use it for cpuidle. Instead, call cpuidle directly, and allow architectures to use pm_idle as an arch-specific default if they need it. ie. cpu_idle() ... if(cpuidle_call_idle()) pm_idle(); cc: x86@kernel.org cc: Kevin Hilman cc: Paul Mundt Signed-off-by: Len Brown --- arch/arm/kernel/process.c | 4 +++- arch/sh/kernel/idle.c | 6 ++++-- arch/x86/kernel/process_32.c | 4 +++- arch/x86/kernel/process_64.c | 4 +++- drivers/cpuidle/cpuidle.c | 39 ++++++++++++++++++--------------------- include/linux/cpuidle.h | 2 ++ 6 files changed, 33 insertions(+), 26 deletions(-) diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 5e1e541..d7ee0d4 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include @@ -196,7 +197,8 @@ void cpu_idle(void) cpu_relax(); } else { stop_critical_timings(); - pm_idle(); + if (cpuidle_call_idle()) + pm_idle(); start_critical_timings(); /* * This will eventually be removed - pm_idle diff --git a/arch/sh/kernel/idle.c b/arch/sh/kernel/idle.c index 425d604..9c7099e 100644 --- a/arch/sh/kernel/idle.c +++ b/arch/sh/kernel/idle.c @@ -16,12 +16,13 @@ #include #include #include +#include #include #include #include #include -void (*pm_idle)(void) = NULL; +static void (*pm_idle)(void); static int hlt_counter; @@ -100,7 +101,8 @@ void cpu_idle(void) local_irq_disable(); /* Don't trace irqs off for idle */ stop_critical_timings(); - pm_idle(); + if (cpuidle_call_idle()) + pm_idle(); /* * Sanity check to ensure that pm_idle() returns * with IRQs enabled diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 8d12878..61fadbe 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -38,6 +38,7 @@ #include #include #include +#include #include #include @@ -109,7 +110,8 @@ void cpu_idle(void) local_irq_disable(); /* Don't trace irqs off for idle */ stop_critical_timings(); - pm_idle(); + if (cpuidle_idle_call()) + pm_idle(); start_critical_timings(); } tick_nohz_restart_sched_tick(); diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 6c9dd92..62c219a 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include @@ -136,7 +137,8 @@ void cpu_idle(void) enter_idle(); /* Don't trace irqs off for idle */ stop_critical_timings(); - pm_idle(); + if (cpuidle_idle_call()) + pm_idle(); start_critical_timings(); /* In many cases the interrupt that ended idle diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 8d7303b..304e378 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -25,10 +25,10 @@ DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices); DEFINE_MUTEX(cpuidle_lock); LIST_HEAD(cpuidle_detected_devices); -static void (*pm_idle_old)(void); static int enabled_devices; static int off __read_mostly; +static int initialized __read_mostly; int cpuidle_disabled(void) { @@ -56,27 +56,24 @@ static int __cpuidle_register_device(struct cpuidle_device *dev); * cpuidle_idle_call - the main idle loop * * NOTE: no locks or semaphores should be used here + * return non-zero on failure */ -static void cpuidle_idle_call(void) +int cpuidle_idle_call(void) { struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); struct cpuidle_driver *drv = cpuidle_get_driver(); struct cpuidle_state *target_state; int next_state, entered_state; - /* check if the device is ready */ - if (!dev || !dev->enabled) { - if (pm_idle_old) - pm_idle_old(); - else -#if defined(CONFIG_ARCH_HAS_DEFAULT_IDLE) - default_idle(); -#else - local_irq_enable(); -#endif - return; - } + if (off) + return -ENODEV; + + if (!initialized) + return -ENODEV; + /* check if the device is ready */ + if (!dev || !dev->enabled) + return -EBUSY; #if 0 /* shows regressions, re-enable for 2.6.29 */ /* @@ -90,7 +87,7 @@ static void cpuidle_idle_call(void) next_state = cpuidle_curr_governor->select(drv, dev); if (need_resched()) { local_irq_enable(); - return; + return 0; } target_state = &drv->states[next_state]; @@ -116,6 +113,8 @@ static void cpuidle_idle_call(void) /* give the governor an opportunity to reflect on the outcome */ if (cpuidle_curr_governor->reflect) cpuidle_curr_governor->reflect(dev, entered_state); + + return 0; } /** @@ -123,10 +122,10 @@ static void cpuidle_idle_call(void) */ void cpuidle_install_idle_handler(void) { - if (enabled_devices && (pm_idle != cpuidle_idle_call)) { + if (enabled_devices) { /* Make sure all changes finished before we switch to new idle */ smp_wmb(); - pm_idle = cpuidle_idle_call; + initialized = 1; } } @@ -135,8 +134,8 @@ void cpuidle_install_idle_handler(void) */ void cpuidle_uninstall_idle_handler(void) { - if (enabled_devices && pm_idle_old && (pm_idle != pm_idle_old)) { - pm_idle = pm_idle_old; + if (enabled_devices) { + initialized = 0; cpuidle_kick_cpus(); } } @@ -410,8 +409,6 @@ static int __init cpuidle_init(void) if (cpuidle_disabled()) return -ENODEV; - pm_idle_old = pm_idle; - ret = cpuidle_add_class_sysfs(&cpu_sysdev_class); if (ret) return ret; diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 2786787..c904188 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -128,6 +128,7 @@ struct cpuidle_driver { #ifdef CONFIG_CPU_IDLE extern void disable_cpuidle(void); +extern int cpuidle_idle_call(void); extern int cpuidle_register_driver(struct cpuidle_driver *drv); struct cpuidle_driver *cpuidle_get_driver(void); @@ -142,6 +143,7 @@ extern void cpuidle_disable_device(struct cpuidle_device *dev); #else static inline void disable_cpuidle(void) { } +static inline int cpuidle_idle_call(void) { return -ENODEV; } static inline int cpuidle_register_driver(struct cpuidle_driver *drv) {return -ENODEV; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/