From 6ddd2a27948f0bd02a2ad001e8a6816898eba0dc Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 9 Jun 2008 16:59:53 +0200 Subject: [PATCH] x86: simplify idle selection default_idle is selected in cpu_idle(), when no other idle routine is selected. Select it in select_idle_routine() when mwait is not selected. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/kernel/process.c | 18 +++++++----------- arch/x86/kernel/process_32.c | 7 +------ arch/x86/kernel/process_64.c | 7 ++----- 3 files changed, 10 insertions(+), 22 deletions(-) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index ba370dc8685..b3078f4ce25 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -139,27 +139,23 @@ static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c) 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 (pm_idle) + return; + 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; + printk(KERN_INFO "using mwait in idle threads.\n"); + pm_idle = mwait_idle; + } else + pm_idle = default_idle; } static int __init idle_setup(char *str) diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index f8476dfbb60..ee4ab461c50 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -168,24 +168,19 @@ void cpu_idle(void) while (1) { tick_nohz_stop_sched_tick(); while (!need_resched()) { - void (*idle)(void); check_pgt_cache(); rmb(); - idle = pm_idle; if (rcu_pending(cpu)) rcu_check_callbacks(cpu, 0); - if (!idle) - idle = default_idle; - if (cpu_is_offline(cpu)) play_dead(); local_irq_disable(); __get_cpu_var(irq_stat).idle_timestamp = jiffies; - idle(); + pm_idle(); } tick_nohz_restart_sched_tick(); preempt_enable_no_resched(); diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index e2319f39988..db3d89a0439 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -150,12 +150,9 @@ void cpu_idle(void) while (1) { tick_nohz_stop_sched_tick(); while (!need_resched()) { - void (*idle)(void); rmb(); - idle = pm_idle; - if (!idle) - idle = default_idle; + if (cpu_is_offline(smp_processor_id())) play_dead(); /* @@ -165,7 +162,7 @@ void cpu_idle(void) */ local_irq_disable(); enter_idle(); - idle(); + pm_idle(); /* In many cases the interrupt that ended idle has already called exit_idle. But some idle loops can be woken up without interrupt. */ -- 2.46.0