From 4ae7d5cefd4aa3560e359a3b0f03e12adc8b5c86 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 19 Mar 2008 01:42:00 +0100 Subject: sched: improve affine wakeups improve affine wakeups. Maintain the 'overlap' metric based on CFS's sum_exec_runtime - which means the amount of time a task executes after it wakes up some other task. Use the 'overlap' for the wakeup decisions: if the 'overlap' is short, it means there's strong workload coupling between this task and the woken up task. If the 'overlap' is large then the workload is decoupled and the scheduler will move them to separate CPUs more easily. ( Also slightly move the preempt_check within try_to_wake_up() - this has no effect on functionality but allows 'early wakeups' (for still-on-rq tasks) to be correctly accounted as well.) Signed-off-by: Ingo Molnar --- include/linux/sched.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/sched.h') diff --git a/include/linux/sched.h b/include/linux/sched.h index 11d8e9a74eff..3625fcaf5d0f 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -929,6 +929,9 @@ struct sched_entity { u64 vruntime; u64 prev_sum_exec_runtime; + u64 last_wakeup; + u64 avg_overlap; + #ifdef CONFIG_SCHEDSTATS u64 wait_start; u64 wait_max; -- cgit v1.2.3 From 9aefd0abd8610e8f3bb097debf3afb73f8b7b210 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Wed, 12 Mar 2008 18:31:58 +0100 Subject: sched: add exported arch_reinit_sched_domains() to header file. Needed so it can be called from outside of sched.c. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky Signed-off-by: Ingo Molnar --- include/linux/sched.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/sched.h') diff --git a/include/linux/sched.h b/include/linux/sched.h index 3625fcaf5d0f..fed07d03364e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -790,6 +790,7 @@ struct sched_domain { }; extern void partition_sched_domains(int ndoms_new, cpumask_t *doms_new); +extern int arch_reinit_sched_domains(void); #endif /* CONFIG_SMP */ -- cgit v1.2.3 From 06d8308c61e54346585b2691c13ee3f90cb6fb2f Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 22 Mar 2008 09:20:24 +0100 Subject: NOHZ: reevaluate idle sleep length after add_timer_on() add_timer_on() can add a timer on a CPU which is currently in a long idle sleep, but the timer wheel is not reevaluated by the nohz code on that CPU. So a timer can be delayed for quite a long time. This triggered a false positive in the clocksource watchdog code. To avoid this we need to wake up the idle CPU and enforce the reevaluation of the timer wheel for the next timer event. Add a function, which checks a given CPU for idle state, marks the idle task with NEED_RESCHED and sends a reschedule IPI to notify the other CPU of the change in the timer wheel. Call this function from add_timer_on(). Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Acked-by: Ingo Molnar Cc: stable@kernel.org -- include/linux/sched.h | 6 ++++++ kernel/sched.c | 43 +++++++++++++++++++++++++++++++++++++++++++ kernel/timer.c | 10 +++++++++- 3 files changed, 58 insertions(+), 1 deletion(-) --- include/linux/sched.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/sched.h') diff --git a/include/linux/sched.h b/include/linux/sched.h index fed07d03364e..6a1e7afb099b 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1541,6 +1541,12 @@ static inline void idle_task_exit(void) {} extern void sched_idle_next(void); +#if defined(CONFIG_NO_HZ) && defined(CONFIG_SMP) +extern void wake_up_idle_cpu(int cpu); +#else +static inline void wake_up_idle_cpu(int cpu) { } +#endif + #ifdef CONFIG_SCHED_DEBUG extern unsigned int sysctl_sched_latency; extern unsigned int sysctl_sched_min_granularity; -- cgit v1.2.3