diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/apm_32.c | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 117 | ||||
| -rw-r--r-- | arch/x86/kernel/process_32.c | 118 | ||||
| -rw-r--r-- | arch/x86/kernel/process_64.c | 123 |
4 files changed, 127 insertions, 234 deletions
diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c index f0030a0..e4ea362 100644 --- a/arch/x86/kernel/apm_32.c +++ b/arch/x86/kernel/apm_32.c @@ -904,6 +904,7 @@ recalc: original_pm_idle(); else default_idle(); + local_irq_disable(); jiffies_since_last_check = jiffies - last_jiffies; if (jiffies_since_last_check > idle_period) goto recalc; @@ -911,6 +912,8 @@ recalc: if (apm_idle_done) apm_do_busy(); + + local_irq_enable(); } /** diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 3004d71..67e9b4a 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -4,6 +4,8 @@ #include <linux/smp.h> #include <linux/slab.h> #include <linux/sched.h> +#include <linux/module.h> +#include <linux/pm.h> struct kmem_cache *task_xstate_cachep; @@ -42,3 +44,118 @@ void arch_task_cache_init(void) __alignof__(union thread_xstate), SLAB_PANIC, NULL); } + +static void do_nothing(void *unused) +{ +} + +/* + * cpu_idle_wait - Used to ensure that all the CPUs discard old value of + * pm_idle and update to new pm_idle value. Required while changing pm_idle + * handler on SMP systems. + * + * Caller must have changed pm_idle to the new value before the call. Old + * pm_idle value will not be used by any CPU after the return of this function. + */ +void cpu_idle_wait(void) +{ + smp_mb(); + /* kick all the CPUs so that they exit out of pm_idle */ + smp_call_function(do_nothing, NULL, 0, 1); +} +EXPORT_SYMBOL_GPL(cpu_idle_wait); + +/* + * This uses new MONITOR/MWAIT instructions on P4 processors with PNI, + * which can obviate IPI to trigger checking of need_resched. + * We execute MONITOR against need_resched and enter optimized wait state + * through MWAIT. Whenever someone changes need_resched, we would be woken + * up from MWAIT (without an IPI). + * + * New with Core Duo processors, MWAIT can take some hints based on CPU + * capability. + */ +void mwait_idle_with_hints(unsigned long ax, unsigned long cx) +{ + if (!need_resched()) { + __monitor((void *)¤t_thread_info()->flags, 0, 0); + smp_mb(); + if (!need_resched()) + __mwait(ax, cx); + } +} + +/* Default MONITOR/MWAIT with no hints, used for default C1 state */ +static void mwait_idle(void) +{ + if (!need_resched()) { + __monitor((void *)¤t_thread_info()->flags, 0, 0); + smp_mb(); + if (!need_resched()) + __sti_mwait(0, 0); + else + local_irq_enable(); + } else + local_irq_enable(); +} + + +static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c) +{ + if (force_mwait) + return 1; + /* Any C1 states supported? */ + return c->cpuid_level >= 5 && ((cpuid_edx(5) >> 4) & 0xf) > 0; +} + +/* + * On SMP it's slightly faster (but much more power-consuming!) + * to poll the ->work.need_resched flag instead of waiting for the + * cross-CPU IPI to arrive. Use this option with caution. + */ +static void poll_idle(void) +{ + local_irq_enable(); + cpu_relax(); +} + +void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) +{ + static int selected; + + if (selected) + return; +#ifdef CONFIG_X86_SMP + if (pm_idle == poll_idle && smp_num_siblings > 1) { + printk(KERN_WARNING "WARNING: polling idle and HT enabled," + " performance may degrade.\n"); + } +#endif + if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) { + /* + * Skip, if setup has overridden idle. + * One CPU supports mwait => All CPUs supports mwait + */ + if (!pm_idle) { + printk(KERN_INFO "using mwait in idle threads.\n"); + pm_idle = mwait_idle; + } + } + selected = 1; +} + +static int __init idle_setup(char *str) +{ + if (!strcmp(str, "poll")) { + printk("using polling idle threads.\n"); + pm_idle = poll_idle; + } else if (!strcmp(str, "mwait")) + force_mwait = 1; + else + return -1; + + boot_option_idle_override = 1; + return 0; +} +early_param("idle", idle_setup); + diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 77de848..f8476df 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -111,12 +111,10 @@ void default_idle(void) */ smp_mb(); - local_irq_disable(); - if (!need_resched()) { + if (!need_resched()) safe_halt(); /* enables interrupts racelessly */ - local_irq_disable(); - } - local_irq_enable(); + else + local_irq_enable(); current_thread_info()->status |= TS_POLLING; } else { local_irq_enable(); @@ -128,17 +126,6 @@ void default_idle(void) EXPORT_SYMBOL(default_idle); #endif -/* - * On SMP it's slightly faster (but much more power-consuming!) - * to poll the ->work.need_resched flag instead of waiting for the - * cross-CPU IPI to arrive. Use this option with caution. - */ -static void poll_idle(void) -{ - local_irq_enable(); - cpu_relax(); -} - #ifdef CONFIG_HOTPLUG_CPU #include <asm/nmi.h> /* We don't actually take CPU down, just spin without interrupts. */ @@ -196,6 +183,7 @@ void cpu_idle(void) if (cpu_is_offline(cpu)) play_dead(); + local_irq_disable(); __get_cpu_var(irq_stat).idle_timestamp = jiffies; idle(); } @@ -206,104 +194,6 @@ void cpu_idle(void) } } -static void do_nothing(void *unused) -{ -} - -/* - * cpu_idle_wait - Used to ensure that all the CPUs discard old value of - * pm_idle and update to new pm_idle value. Required while changing pm_idle - * handler on SMP systems. - * - * Caller must have changed pm_idle to the new value before the call. Old - * pm_idle value will not be used by any CPU after the return of this function. - */ -void cpu_idle_wait(void) -{ - smp_mb(); - /* kick all the CPUs so that they exit out of pm_idle */ - smp_call_function(do_nothing, NULL, 0, 1); -} -EXPORT_SYMBOL_GPL(cpu_idle_wait); - -/* - * This uses new MONITOR/MWAIT instructions on P4 processors with PNI, - * which can obviate IPI to trigger checking of need_resched. - * We execute MONITOR against need_resched and enter optimized wait state - * through MWAIT. Whenever someone changes need_resched, we would be woken - * up from MWAIT (without an IPI). - * - * New with Core Duo processors, MWAIT can take some hints based on CPU - * capability. - */ -void mwait_idle_with_hints(unsigned long ax, unsigned long cx) -{ - if (!need_resched()) { - __monitor((void *)¤t_thread_info()->flags, 0, 0); - smp_mb(); - if (!need_resched()) - __sti_mwait(ax, cx); - else - local_irq_enable(); - } else - local_irq_enable(); -} - -/* Default MONITOR/MWAIT with no hints, used for default C1 state */ -static void mwait_idle(void) -{ - local_irq_enable(); - mwait_idle_with_hints(0, 0); -} - -static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c) -{ - if (force_mwait) - return 1; - /* Any C1 states supported? */ - return c->cpuid_level >= 5 && ((cpuid_edx(5) >> 4) & 0xf) > 0; -} - -void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) -{ - static int selected; - - if (selected) - return; -#ifdef CONFIG_X86_SMP - if (pm_idle == poll_idle && smp_num_siblings > 1) { - printk(KERN_WARNING "WARNING: polling idle and HT enabled," - " performance may degrade.\n"); - } -#endif - if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) { - /* - * Skip, if setup has overridden idle. - * One CPU supports mwait => All CPUs supports mwait - */ - if (!pm_idle) { - printk(KERN_INFO "using mwait in idle threads.\n"); - pm_idle = mwait_idle; - } - } - selected = 1; -} - -static int __init idle_setup(char *str) -{ - if (!strcmp(str, "poll")) { - printk("using polling idle threads.\n"); - pm_idle = poll_idle; - } else if (!strcmp(str, "mwait")) - force_mwait = 1; - else - return -1; - - boot_option_idle_override = 1; - return 0; -} -early_param("idle", idle_setup); - void __show_registers(struct pt_regs *regs, int all) { unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L; diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 131c2ee..e2319f3 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -106,26 +106,13 @@ void default_idle(void) * test NEED_RESCHED: */ smp_mb(); - local_irq_disable(); - if (!need_resched()) { + if (!need_resched()) safe_halt(); /* enables interrupts racelessly */ - local_irq_disable(); - } - local_irq_enable(); + else + local_irq_enable(); current_thread_info()->status |= TS_POLLING; } -/* - * On SMP it's slightly faster (but much more power-consuming!) - * to poll the ->need_resched flag instead of waiting for the - * cross-CPU IPI to arrive. Use this option with caution. - */ -static void poll_idle(void) -{ - local_irq_enable(); - cpu_relax(); -} - #ifdef CONFIG_HOTPLUG_CPU DECLARE_PER_CPU(int, cpu_state); @@ -192,110 +179,6 @@ void cpu_idle(void) } } -static void do_nothing(void *unused) -{ -} - -/* - * cpu_idle_wait - Used to ensure that all the CPUs discard old value of - * pm_idle and update to new pm_idle value. Required while changing pm_idle - * handler on SMP systems. - * - * Caller must have changed pm_idle to the new value before the call. Old - * pm_idle value will not be used by any CPU after the return of this function. - */ -void cpu_idle_wait(void) -{ - smp_mb(); - /* kick all the CPUs so that they exit out of pm_idle */ - smp_call_function(do_nothing, NULL, 0, 1); -} -EXPORT_SYMBOL_GPL(cpu_idle_wait); - -/* - * This uses new MONITOR/MWAIT instructions on P4 processors with PNI, - * which can obviate IPI to trigger checking of need_resched. - * We execute MONITOR against need_resched and enter optimized wait state - * through MWAIT. Whenever someone changes need_resched, we would be woken - * up from MWAIT (without an IPI). - * - * New with Core Duo processors, MWAIT can take some hints based on CPU - * capability. - */ -void mwait_idle_with_hints(unsigned long ax, unsigned long cx) -{ - if (!need_resched()) { - __monitor((void *)¤t_thread_info()->flags, 0, 0); - smp_mb(); - if (!need_resched()) - __mwait(ax, cx); - } -} - -/* Default MONITOR/MWAIT with no hints, used for default C1 state */ -static void mwait_idle(void) -{ - if (!need_resched()) { - __monitor((void *)¤t_thread_info()->flags, 0, 0); - smp_mb(); - if (!need_resched()) - __sti_mwait(0, 0); - else - local_irq_enable(); - } else { - local_irq_enable(); - } -} - - -static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c) -{ - if (force_mwait) - return 1; - /* Any C1 states supported? */ - return c->cpuid_level >= 5 && ((cpuid_edx(5) >> 4) & 0xf) > 0; -} - -void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) -{ - static int selected; - - if (selected) - return; -#ifdef CONFIG_X86_SMP - if (pm_idle == poll_idle && smp_num_siblings > 1) { - printk(KERN_WARNING "WARNING: polling idle and HT enabled," - " performance may degrade.\n"); - } -#endif - if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) { - /* - * Skip, if setup has overridden idle. - * One CPU supports mwait => All CPUs supports mwait - */ - if (!pm_idle) { - printk(KERN_INFO "using mwait in idle threads.\n"); - pm_idle = mwait_idle; - } - } - selected = 1; -} - -static int __init idle_setup(char *str) -{ - if (!strcmp(str, "poll")) { - printk("using polling idle threads.\n"); - pm_idle = poll_idle; - } else if (!strcmp(str, "mwait")) - force_mwait = 1; - else - return -1; - - boot_option_idle_override = 1; - return 0; -} -early_param("idle", idle_setup); - /* Prints also some state that isn't saved in the pt_regs */ void __show_regs(struct pt_regs * regs) { |
