From 6cd8a4bb2f97527a9ceb30bc77ea4e959c6a95e3 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 12 May 2008 21:20:42 +0200 Subject: ftrace: trace preempt off critical timings Add preempt off timings. A lot of kernel core code is taken from the RT patch latency trace that was written by Ingo Molnar. This adds "preemptoff" and "preemptirqsoff" to /debugfs/tracing/available_tracers Now instead of just tracing irqs off, preemption off can be selected to be recorded. When this is selected, it shares the same files as irqs off timings. One can either trace preemption off, irqs off, or one or the other off. By echoing "preemptoff" into /debugfs/tracing/current_tracer, recording of preempt off only is performed. "irqsoff" will only record the time irqs are disabled, but "preemptirqsoff" will take the total time irqs or preemption are disabled. Runtime switching of these options is now supported by simpling echoing in the appropriate trace name into /debugfs/tracing/current_tracer. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/process_32.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/x86/kernel/process_32.c') diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index f8476dfbb60..a30aa1f2607 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -185,7 +185,10 @@ void cpu_idle(void) local_irq_disable(); __get_cpu_var(irq_stat).idle_timestamp = jiffies; + /* Don't trace irqs off for idle */ + stop_critical_timings(); idle(); + start_critical_timings(); } tick_nohz_restart_sched_tick(); preempt_enable_no_resched(); -- cgit v1.2.3 From 6ddd2a27948f0bd02a2ad001e8a6816898eba0dc Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 9 Jun 2008 16:59:53 +0200 Subject: 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_32.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) (limited to 'arch/x86/kernel/process_32.c') 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(); -- cgit v1.2.3 From 00dba56465228825ea806e3a7fc0aa6bba7bdc6c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 9 Jun 2008 18:35:28 +0200 Subject: x86: move more common idle functions/variables to process.c more unification. Should cause no change in functionality. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/kernel/process_32.c | 54 -------------------------------------------- 1 file changed, 54 deletions(-) (limited to 'arch/x86/kernel/process_32.c') diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index ee4ab461c50..ae4020486a9 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -58,11 +58,6 @@ asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); -static int hlt_counter; - -unsigned long boot_option_idle_override = 0; -EXPORT_SYMBOL(boot_option_idle_override); - DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task; EXPORT_PER_CPU_SYMBOL(current_task); @@ -77,55 +72,6 @@ unsigned long thread_saved_pc(struct task_struct *tsk) return ((unsigned long *)tsk->thread.sp)[3]; } -/* - * Powermanagement idle function, if any.. - */ -void (*pm_idle)(void); -EXPORT_SYMBOL(pm_idle); - -void disable_hlt(void) -{ - hlt_counter++; -} - -EXPORT_SYMBOL(disable_hlt); - -void enable_hlt(void) -{ - hlt_counter--; -} - -EXPORT_SYMBOL(enable_hlt); - -/* - * We use this if we don't have any better - * idle routine.. - */ -void default_idle(void) -{ - if (!hlt_counter && boot_cpu_data.hlt_works_ok) { - current_thread_info()->status &= ~TS_POLLING; - /* - * TS_POLLING-cleared state must be visible before we - * test NEED_RESCHED: - */ - smp_mb(); - - if (!need_resched()) - safe_halt(); /* enables interrupts racelessly */ - else - local_irq_enable(); - current_thread_info()->status |= TS_POLLING; - } else { - local_irq_enable(); - /* loop is done by the caller */ - cpu_relax(); - } -} -#ifdef CONFIG_APM_MODULE -EXPORT_SYMBOL(default_idle); -#endif - #ifdef CONFIG_HOTPLUG_CPU #include /* We don't actually take CPU down, just spin without interrupts. */ -- cgit v1.2.3 From 1481a3dd42c21ac4a8b9497cb9f5df816d6b064f Mon Sep 17 00:00:00 2001 From: Glauber Costa Date: Wed, 4 Jun 2008 15:35:03 -0300 Subject: x86: move cpu_exit_clear to process_32.c Take it out of smpboot.c, and move it to process_32.c, closer to its only user. Signed-off-by: Glauber Costa Signed-off-by: Ingo Molnar --- arch/x86/kernel/process_32.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'arch/x86/kernel/process_32.c') diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index c2a11d77b1b..9a139f6c9df 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -74,6 +74,22 @@ unsigned long thread_saved_pc(struct task_struct *tsk) #ifdef CONFIG_HOTPLUG_CPU #include + +static void cpu_exit_clear(void) +{ + int cpu = raw_smp_processor_id(); + + idle_task_exit(); + + cpu_uninit(); + irq_ctx_exit(cpu); + + cpu_clear(cpu, cpu_callout_map); + cpu_clear(cpu, cpu_callin_map); + + numa_remove_cpu(cpu); +} + /* We don't actually take CPU down, just spin without interrupts. */ static inline void play_dead(void) { -- cgit v1.2.3