Re: [patch] voluntary-preempt-2.6.8-rc4-O7

Lee Revell
2004-08-13T20:27:48Z

On Fri, 2004-08-13 at 06:48, Ingo Molnar wrote:

> http://redhat.com/~mingo/voluntary-preempt/voluntary-preempt-2.6.8-rc4-O7
>

Here's another very common one. I am not sure this one is a problem,
but possibly points to areas where the VM (or XFree86) could be
improved.

preemption latency trace v1.0
-----------------------------
latency: 166 us, entries: 305 (305)
process: XFree86/478, uid: 0
nice: 0, policy: 0, rt_priority: 0
=======>
0.000ms (+0.000ms): unmap_page_range (unmap_vmas)
0.000ms (+0.000ms): zap_pmd_range (unmap_page_range)
0.000ms (+0.000ms): zap_pte_range (zap_pmd_range)
0.002ms (+0.001ms): set_page_dirty (zap_pte_range)
0.003ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.003ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.004ms (+0.000ms): __page_cache_release (zap_pte_range)
0.005ms (+0.001ms): free_hot_page (zap_pte_range)
0.005ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.006ms (+0.001ms): set_page_dirty (zap_pte_range)
0.007ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.007ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.007ms (+0.000ms): __page_cache_release (zap_pte_range)
0.008ms (+0.000ms): free_hot_page (zap_pte_range)
0.008ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.009ms (+0.000ms): set_page_dirty (zap_pte_range)
0.009ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.010ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.010ms (+0.000ms): __page_cache_release (zap_pte_range)
0.011ms (+0.000ms): free_hot_page (zap_pte_range)
0.011ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.012ms (+0.000ms): set_page_dirty (zap_pte_range)
0.012ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.013ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.013ms (+0.000ms): __page_cache_release (zap_pte_range)
0.014ms (+0.000ms): free_hot_page (zap_pte_range)
0.014ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.015ms (+0.000ms): set_page_dirty (zap_pte_range)
0.015ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.016ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.016ms (+0.000ms): __page_cache_release (zap_pte_range)
0.016ms (+0.000ms): free_hot_page (zap_pte_range)
0.017ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.017ms (+0.000ms): set_page_dirty (zap_pte_range)
0.018ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.018ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.019ms (+0.000ms): __page_cache_release (zap_pte_range)
0.019ms (+0.000ms): free_hot_page (zap_pte_range)
0.019ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.020ms (+0.000ms): set_page_dirty (zap_pte_range)
0.021ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.021ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.021ms (+0.000ms): __page_cache_release (zap_pte_range)
0.022ms (+0.000ms): free_hot_page (zap_pte_range)
0.022ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.023ms (+0.000ms): free_pages_bulk (free_hot_cold_page)
0.037ms (+0.014ms): do_IRQ (common_interrupt)
0.038ms (+0.000ms): mask_and_ack_8259A (do_IRQ)
0.041ms (+0.003ms): generic_redirect_hardirq (do_IRQ)
0.042ms (+0.000ms): generic_handle_IRQ_event (do_IRQ)
0.042ms (+0.000ms): timer_interrupt (generic_handle_IRQ_event)
0.043ms (+0.000ms): mark_offset_tsc (timer_interrupt)
0.048ms (+0.005ms): do_timer (timer_interrupt)
0.049ms (+0.000ms): update_process_times (do_timer)
0.049ms (+0.000ms): update_one_process (update_process_times)
0.050ms (+0.000ms): run_local_timers (update_process_times)
0.050ms (+0.000ms): raise_softirq (update_process_times)
0.050ms (+0.000ms): scheduler_tick (update_process_times)
0.051ms (+0.000ms): sched_clock (scheduler_tick)
0.052ms (+0.001ms): task_timeslice (scheduler_tick)
0.052ms (+0.000ms): update_wall_time (do_timer)
0.052ms (+0.000ms): update_wall_time_one_tick (update_wall_time)
0.053ms (+0.000ms): generic_note_interrupt (do_IRQ)
0.053ms (+0.000ms): end_8259A_irq (do_IRQ)
0.054ms (+0.000ms): enable_8259A_irq (do_IRQ)
0.055ms (+0.001ms): do_softirq (do_IRQ)
0.055ms (+0.000ms): __do_softirq (do_softirq)
0.056ms (+0.000ms): wake_up_process (do_softirq)
0.056ms (+0.000ms): try_to_wake_up (wake_up_process)
0.056ms (+0.000ms): task_rq_lock (try_to_wake_up)
0.057ms (+0.000ms): activate_task (try_to_wake_up)
0.057ms (+0.000ms): sched_clock (activate_task)
0.058ms (+0.000ms): recalc_task_prio (activate_task)
0.058ms (+0.000ms): effective_prio (recalc_task_prio)
0.058ms (+0.000ms): enqueue_task (activate_task)
0.059ms (+0.000ms): preempt_schedule (try_to_wake_up)
0.060ms (+0.000ms): preempt_schedule (zap_pte_range)
0.060ms (+0.000ms): set_page_dirty (zap_pte_range)
0.060ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.061ms (+0.000ms): preempt_schedule (zap_pte_range)
0.061ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.061ms (+0.000ms): __page_cache_release (zap_pte_range)
0.062ms (+0.000ms): preempt_schedule (__page_cache_release)
0.062ms (+0.000ms): free_hot_page (zap_pte_range)
0.063ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.063ms (+0.000ms): preempt_schedule (zap_pte_range)
0.064ms (+0.000ms): set_page_dirty (zap_pte_range)
0.064ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.064ms (+0.000ms): preempt_schedule (zap_pte_range)
0.065ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.065ms (+0.000ms): __page_cache_release (zap_pte_range)
0.066ms (+0.000ms): preempt_schedule (__page_cache_release)
0.066ms (+0.000ms): free_hot_page (zap_pte_range)
0.066ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.067ms (+0.000ms): preempt_schedule (zap_pte_range)
0.067ms (+0.000ms): set_page_dirty (zap_pte_range)
0.068ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.068ms (+0.000ms): preempt_schedule (zap_pte_range)
0.068ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.069ms (+0.000ms): __page_cache_release (zap_pte_range)
0.069ms (+0.000ms): preempt_schedule (__page_cache_release)
0.070ms (+0.000ms): free_hot_page (zap_pte_range)
0.070ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.071ms (+0.000ms): preempt_schedule (zap_pte_range)
0.071ms (+0.000ms): set_page_dirty (zap_pte_range)
0.071ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.072ms (+0.000ms): preempt_schedule (zap_pte_range)
0.072ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.072ms (+0.000ms): __page_cache_release (zap_pte_range)
0.073ms (+0.000ms): preempt_schedule (__page_cache_release)
0.073ms (+0.000ms): free_hot_page (zap_pte_range)
0.073ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.074ms (+0.000ms): preempt_schedule (zap_pte_range)
0.074ms (+0.000ms): set_page_dirty (zap_pte_range)
0.075ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.075ms (+0.000ms): preempt_schedule (zap_pte_range)
0.075ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.076ms (+0.000ms): __page_cache_release (zap_pte_range)
0.076ms (+0.000ms): preempt_schedule (__page_cache_release)
0.077ms (+0.000ms): free_hot_page (zap_pte_range)
0.077ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.078ms (+0.000ms): preempt_schedule (zap_pte_range)
0.078ms (+0.000ms): set_page_dirty (zap_pte_range)
0.078ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.079ms (+0.000ms): preempt_schedule (zap_pte_range)
0.079ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.079ms (+0.000ms): __page_cache_release (zap_pte_range)
0.080ms (+0.000ms): preempt_schedule (__page_cache_release)
0.080ms (+0.000ms): free_hot_page (zap_pte_range)
0.081ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.081ms (+0.000ms): preempt_schedule (zap_pte_range)
0.082ms (+0.000ms): set_page_dirty (zap_pte_range)
0.082ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.082ms (+0.000ms): preempt_schedule (zap_pte_range)
0.083ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.083ms (+0.000ms): __page_cache_release (zap_pte_range)
0.084ms (+0.000ms): preempt_schedule (__page_cache_release)
0.084ms (+0.000ms): free_hot_page (zap_pte_range)
0.084ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.085ms (+0.000ms): preempt_schedule (zap_pte_range)
0.085ms (+0.000ms): set_page_dirty (zap_pte_range)
0.086ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.086ms (+0.000ms): preempt_schedule (zap_pte_range)
0.086ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.087ms (+0.000ms): __page_cache_release (zap_pte_range)
0.087ms (+0.000ms): preempt_schedule (__page_cache_release)
0.088ms (+0.000ms): free_hot_page (zap_pte_range)
0.088ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.088ms (+0.000ms): preempt_schedule (zap_pte_range)
0.089ms (+0.000ms): set_page_dirty (zap_pte_range)
0.089ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.090ms (+0.000ms): preempt_schedule (zap_pte_range)
0.090ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.090ms (+0.000ms): __page_cache_release (zap_pte_range)
0.091ms (+0.000ms): preempt_schedule (__page_cache_release)
0.091ms (+0.000ms): free_hot_page (zap_pte_range)
0.091ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.092ms (+0.000ms): preempt_schedule (zap_pte_range)
0.092ms (+0.000ms): set_page_dirty (zap_pte_range)
0.093ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.093ms (+0.000ms): preempt_schedule (zap_pte_range)
0.093ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.094ms (+0.000ms): __page_cache_release (zap_pte_range)
0.094ms (+0.000ms): preempt_schedule (__page_cache_release)
0.095ms (+0.000ms): free_hot_page (zap_pte_range)
0.095ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.096ms (+0.000ms): preempt_schedule (zap_pte_range)
0.096ms (+0.000ms): set_page_dirty (zap_pte_range)
0.096ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.097ms (+0.000ms): preempt_schedule (zap_pte_range)
0.097ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.097ms (+0.000ms): __page_cache_release (zap_pte_range)
0.098ms (+0.000ms): preempt_schedule (__page_cache_release)
0.098ms (+0.000ms): free_hot_page (zap_pte_range)
0.099ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.099ms (+0.000ms): preempt_schedule (zap_pte_range)
0.100ms (+0.000ms): set_page_dirty (zap_pte_range)
0.100ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.100ms (+0.000ms): preempt_schedule (zap_pte_range)
0.101ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.101ms (+0.000ms): __page_cache_release (zap_pte_range)
0.102ms (+0.000ms): preempt_schedule (__page_cache_release)
0.102ms (+0.000ms): free_hot_page (zap_pte_range)
0.102ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.103ms (+0.000ms): preempt_schedule (zap_pte_range)
0.103ms (+0.000ms): set_page_dirty (zap_pte_range)
0.104ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.104ms (+0.000ms): preempt_schedule (zap_pte_range)
0.104ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.105ms (+0.000ms): __page_cache_release (zap_pte_range)
0.105ms (+0.000ms): preempt_schedule (__page_cache_release)
0.106ms (+0.000ms): free_hot_page (zap_pte_range)
0.106ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.106ms (+0.000ms): preempt_schedule (zap_pte_range)
0.107ms (+0.000ms): set_page_dirty (zap_pte_range)
0.107ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.108ms (+0.000ms): preempt_schedule (zap_pte_range)
0.108ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.108ms (+0.000ms): __page_cache_release (zap_pte_range)
0.109ms (+0.000ms): preempt_schedule (__page_cache_release)
0.109ms (+0.000ms): free_hot_page (zap_pte_range)
0.110ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.110ms (+0.000ms): preempt_schedule (zap_pte_range)
0.110ms (+0.000ms): set_page_dirty (zap_pte_range)
0.111ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.111ms (+0.000ms): preempt_schedule (zap_pte_range)
0.111ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.112ms (+0.000ms): __page_cache_release (zap_pte_range)
0.112ms (+0.000ms): preempt_schedule (__page_cache_release)
0.113ms (+0.000ms): free_hot_page (zap_pte_range)
0.113ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.114ms (+0.000ms): preempt_schedule (zap_pte_range)
0.114ms (+0.000ms): set_page_dirty (zap_pte_range)
0.114ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.115ms (+0.000ms): preempt_schedule (zap_pte_range)
0.115ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.115ms (+0.000ms): __page_cache_release (zap_pte_range)
0.116ms (+0.000ms): preempt_schedule (__page_cache_release)
0.116ms (+0.000ms): free_hot_page (zap_pte_range)
0.117ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.117ms (+0.000ms): free_pages_bulk (free_hot_cold_page)
0.128ms (+0.011ms): preempt_schedule (free_pages_bulk)
0.129ms (+0.000ms): preempt_schedule (zap_pte_range)
0.129ms (+0.000ms): set_page_dirty (zap_pte_range)
0.130ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.130ms (+0.000ms): preempt_schedule (zap_pte_range)
0.130ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.131ms (+0.000ms): __page_cache_release (zap_pte_range)
0.131ms (+0.000ms): preempt_schedule (__page_cache_release)
0.132ms (+0.000ms): free_hot_page (zap_pte_range)
0.132ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.132ms (+0.000ms): preempt_schedule (zap_pte_range)
0.133ms (+0.000ms): set_page_dirty (zap_pte_range)
0.133ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.134ms (+0.000ms): preempt_schedule (zap_pte_range)
0.134ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.134ms (+0.000ms): __page_cache_release (zap_pte_range)
0.135ms (+0.000ms): preempt_schedule (__page_cache_release)
0.135ms (+0.000ms): free_hot_page (zap_pte_range)
0.135ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.136ms (+0.000ms): preempt_schedule (zap_pte_range)
0.136ms (+0.000ms): set_page_dirty (zap_pte_range)
0.137ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.137ms (+0.000ms): preempt_schedule (zap_pte_range)
0.137ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.138ms (+0.000ms): __page_cache_release (zap_pte_range)
0.138ms (+0.000ms): preempt_schedule (__page_cache_release)
0.139ms (+0.000ms): free_hot_page (zap_pte_range)
0.139ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.139ms (+0.000ms): preempt_schedule (zap_pte_range)
0.140ms (+0.000ms): set_page_dirty (zap_pte_range)
0.140ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.141ms (+0.000ms): preempt_schedule (zap_pte_range)
0.141ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.141ms (+0.000ms): __page_cache_release (zap_pte_range)
0.142ms (+0.000ms): preempt_schedule (__page_cache_release)
0.142ms (+0.000ms): free_hot_page (zap_pte_range)
0.142ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.143ms (+0.000ms): preempt_schedule (zap_pte_range)
0.144ms (+0.000ms): set_page_dirty (zap_pte_range)
0.144ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.145ms (+0.000ms): preempt_schedule (zap_pte_range)
0.145ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.145ms (+0.000ms): __page_cache_release (zap_pte_range)
0.146ms (+0.000ms): preempt_schedule (__page_cache_release)
0.146ms (+0.000ms): free_hot_page (zap_pte_range)
0.146ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.147ms (+0.000ms): preempt_schedule (zap_pte_range)
0.147ms (+0.000ms): set_page_dirty (zap_pte_range)
0.148ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.148ms (+0.000ms): preempt_schedule (zap_pte_range)
0.148ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.149ms (+0.000ms): __page_cache_release (zap_pte_range)
0.149ms (+0.000ms): preempt_schedule (__page_cache_release)
0.149ms (+0.000ms): free_hot_page (zap_pte_range)
0.150ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.150ms (+0.000ms): preempt_schedule (zap_pte_range)
0.151ms (+0.000ms): set_page_dirty (zap_pte_range)
0.151ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.152ms (+0.000ms): preempt_schedule (zap_pte_range)
0.152ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.152ms (+0.000ms): __page_cache_release (zap_pte_range)
0.153ms (+0.000ms): preempt_schedule (__page_cache_release)
0.153ms (+0.000ms): free_hot_page (zap_pte_range)
0.153ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.154ms (+0.000ms): preempt_schedule (zap_pte_range)
0.154ms (+0.000ms): set_page_dirty (zap_pte_range)
0.155ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.155ms (+0.000ms): preempt_schedule (zap_pte_range)
0.155ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.155ms (+0.000ms): __page_cache_release (zap_pte_range)
0.156ms (+0.000ms): preempt_schedule (__page_cache_release)
0.156ms (+0.000ms): free_hot_page (zap_pte_range)
0.157ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.157ms (+0.000ms): preempt_schedule (zap_pte_range)
0.158ms (+0.000ms): set_page_dirty (zap_pte_range)
0.158ms (+0.000ms): page_remove_rmap (zap_pte_range)
0.159ms (+0.000ms): preempt_schedule (zap_pte_range)
0.159ms (+0.000ms): free_page_and_swap_cache (zap_pte_range)
0.159ms (+0.000ms): __page_cache_release (zap_pte_range)
0.160ms (+0.000ms): preempt_schedule (__page_cache_release)
0.160ms (+0.000ms): free_hot_page (zap_pte_range)
0.160ms (+0.000ms): free_hot_cold_page (zap_pte_range)
0.161ms (+0.000ms): preempt_schedule (zap_pte_range)
0.161ms (+0.000ms): check_preempt_timing (touch_preempt_timing)