Nicholas Piggin <npig...@gmail.com> writes:
> On Fri, 17 Mar 2017 17:12:11 +1100
> Michael Ellerman <m...@ellerman.id.au> wrote:
>> Michael Ellerman <m...@ellerman.id.au> writes:
>> > Nicholas Piggin <npig...@gmail.com> writes:
>> >> I would like to start using a dedicated stack for system reset interrupt
>> >> and treat it as a Linux nmi, which makes it tricky to call complex
>> >> interrupt handlers directly from the system reset trap handler.
>> >>
>> >> So I would like to remove the decrementer and external handler calls from
>> >> Cell and Pasemi platforms' system reset handler. I think we can just
>> >> remove them if they can be handled when they re-fire as normal interrupts?
>> >> At the moment I don't have environments set up to test if this works.
>> >
>> > My QS22 has booted OK with it applied, so it seems OK.
>> >
>> > I'll test it a bit more tomorrow.
>>
>> OK, seems fine, and I have a trace that shows it's definitely going
>> through that path:
>
> Thanks for testing it.
>
>> 1) | .default_idle_call() {
>> 1) | .arch_cpu_idle() {
>> 1) | .cbe_power_save() {
>> 1) 0.128 us | .prep_irq_for_idle();
>> 1) | .system_reset_exception() {
>> 1) 0.512 us | .cbe_system_reset_exception();
>> 1) 6.016 us | }
>> 1) | .do_IRQ() {
>
> It seems to do the right thing. I think decrementer should be working
> proprely by setting it to 1 to get another exception?
Yeah it is. It wasn't showing up in traces but I fixed that and here it
is below.
I'll try and test pasemi on Monday, but this looks fine for Cell.
cheers
1) | .default_idle_call() {
1) | .arch_cpu_idle() {
1) | .cbe_power_save() {
1) 0.192 us | .prep_irq_for_idle();
1) | .system_reset_exception() {
1) 0.320 us | .cbe_system_reset_exception();
1) 6.016 us | }
1) | .timer_interrupt() {
1) | .irq_enter() {
1) 0.768 us | .rcu_irq_enter();
1) | .tick_irq_enter() {
1) 0.256 us | .tick_check_oneshot_broadcast_this_cpu();
1) | .ktime_get() {
1) 0.192 us | .timebase_read();
1) 5.504 us | }
1) | .update_ts_time_stats() {
1) 0.640 us | .nr_iowait_cpu();
1) 6.656 us | }
1) + 28.160 us | }
1) | ._local_bh_enable() {
1) 0.192 us | .__local_bh_enable();
1) 5.120 us | }
1) | .vtime_account_irq_enter() {
1) | .vtime_account_idle() {
1) 0.320 us | .vtime_delta.isra.5();
1) 5.504 us | }
1) + 10.560 us | }
1) + 66.048 us | }
1) | .__timer_interrupt() {
1) | .hrtimer_interrupt() {
1) 0.448 us | ._raw_spin_lock();
1) | .ktime_get_update_offsets_now() {
1) 0.256 us | .timebase_read();
1) 5.760 us | }
1) | .__hrtimer_run_queues() {
1) 0.960 us | .__remove_hrtimer();
1) | .tick_sched_timer() {
1) | .ktime_get() {
1) 0.320 us | .timebase_read();
1) 5.888 us | }
1) | .tick_sched_do_timer() {
1) | .tick_do_update_jiffies64.part.14() {
1) 0.384 us | ._raw_spin_lock();
1) | .do_timer() {
1) 0.640 us | .calc_global_load();
1) 5.632 us | }
1) | .update_wall_time() {
1) 0.576 us | ._raw_spin_lock_irqsave();
1) 0.192 us | .timebase_read();
1) 0.192 us | .ntp_tick_length();
1) 0.256 us | .ntp_tick_length();
1) 0.192 us | .ntp_tick_length();
1) | .timekeeping_update() {
1) 0.192 us | .ntp_get_next_leap();
1) 1.600 us | .update_vsyscall_old();
1) | .raw_notifier_call_chain() {
1) 0.768 us | .notifier_call_chain();
1) 5.760 us | }
1) 0.768 us | .update_fast_timekeeper();
1) 0.384 us | .update_fast_timekeeper();
1) + 34.304 us | }
1) 0.192 us | ._raw_spin_unlock_irqrestore();
1) + 75.264 us | }
1) + 98.048 us | }
1) ! 103.552 us | }
1) | .tick_sched_handle.isra.16() {
1) | .update_process_times() {
1) | .vtime_flush() {
1) 0.576 us | .account_idle_time();
1) 5.952 us | }
1) | .run_local_timers() {
1) 0.192 us | .hrtimer_run_queues();
1) | .raise_softirq() {
1) 0.704 us | .__raise_softirq_irqoff();
1) 5.440 us | }
1) + 16.128 us | }
1) | .rcu_check_callbacks() {
1) 0.256 us | .rcu_sched_qs();
1) 0.256 us | .cpu_needs_another_gp();
1) 0.192 us | .cpu_needs_another_gp();
1) + 17.536 us | }
1) | .scheduler_tick() {
1) 0.448 us | ._raw_spin_lock();
1) 0.640 us | .update_rq_clock();
1) 0.192 us | .task_tick_idle();
1) | .cpu_load_update_active() {
1) 0.576 us | .tick_nohz_tick_stopped();
1) | .cpu_load_update() {
1) 0.192 us | .decay_load_missed();
1) 0.256 us | .decay_load_missed();
1) 0.192 us | .decay_load_missed();
1) 0.192 us | .decay_load_missed();
1) 0.256 us | .decay_load_missed();
1) 0.192 us | .decay_load_missed();
1) 0.128 us | .decay_load_missed();
1) 0.576 us | .decay_load_missed();
1) 0.448 us | .sched_avg_update();
1) + 46.592 us | }
1) + 57.088 us | }
1) 0.256 us | .calc_global_load_tick();
1) | .trigger_load_balance() {
1) | .raise_softirq() {
1) 0.256 us | .__raise_softirq_irqoff();
1) 5.504 us | }
1) + 10.496 us | }
1) + 99.456 us | }
1) 0.896 us | .run_posix_cpu_timers();
1) ! 165.504 us | }
1) 0.256 us | .profile_tick();
1) ! 175.744 us | }
1) | .hrtimer_forward() {
1) 0.192 us | .ktime_add_safe();
1) 0.192 us | .ktime_add_safe();
1) + 10.880 us | }
1) ! 315.968 us | }
1) 0.320 us | ._raw_spin_lock();
1) 0.704 us | .enqueue_hrtimer();
1) ! 339.072 us | }
1) 0.256 us | .__hrtimer_get_next_event();
1) | .tick_program_event() {
1) | .clockevents_program_event() {
1) | .ktime_get() {
1) 0.192 us | .timebase_read();
1) 5.568 us | }
1) 0.192 us | .decrementer_set_next_event();
1) + 16.448 us | }
1) + 21.888 us | }
1) ! 393.152 us | }
1) ! 398.592 us | }
1) | .irq_exit() {
1) | .vtime_account_system() {
1) 0.320 us | .vtime_delta.isra.5();
1) 5.760 us | }
1) | .__do_softirq() {
1) | .vtime_account_irq_enter() {
1) | .vtime_account_idle() {
1) 0.256 us | .vtime_delta.isra.5();
1) 5.632 us | }
1) + 10.944 us | }
1) | .run_timer_softirq() {
1) 0.896 us | ._raw_spin_lock_irq();
1) 0.640 us | .collect_expired_timers();
1) 0.320 us | ._raw_spin_lock_irq();
1) 0.256 us | .collect_expired_timers();
1) + 23.552 us | }
1) | .run_rebalance_domains() {
1) | .rebalance_domains() {
1) 0.256 us | ._raw_spin_lock_irqsave();
1) 0.320 us | .update_rq_clock();
1) 0.256 us | .__compute_runnable_contrib();
1) 0.256 us | ._raw_spin_unlock_irqrestore();
1) 0.384 us | .__msecs_to_jiffies();
1) | .load_balance() {
1) 0.320 us | .idle_cpu();
1) | .find_busiest_group() {
1) | .update_group_capacity() {
1) 0.448 us | .__msecs_to_jiffies();
1) 6.016 us | }
1) 0.576 us | .idle_cpu();
1) + 18.624 us | }
1) + 31.680 us | }
1) 0.192 us | .__msecs_to_jiffies();
1) 0.128 us | .__msecs_to_jiffies();
1) 0.576 us | ._raw_spin_trylock();
1) | .load_balance() {
1) 0.256 us | .idle_cpu();
1) 0.192 us | .idle_cpu();
1) | .find_busiest_group() {
1) | .update_group_capacity() {
1) 0.192 us | .__msecs_to_jiffies();
1) 5.632 us | }
1) 0.256 us | .idle_cpu();
1) 0.576 us | .idle_cpu();
1) 0.768 us | .idle_cpu();
1) + 31.808 us | }
1) + 47.872 us | }
1) 0.128 us | .__msecs_to_jiffies();
1) ! 141.504 us | }
1) ! 147.328 us | }
1) 0.320 us | .rcu_bh_qs();
1) | .vtime_account_system() {
1) 0.320 us | .vtime_delta.isra.5();
1) 5.568 us | }
1) 0.192 us | .__local_bh_enable();
1) ! 220.416 us | }
1) 0.832 us | .idle_cpu();
1) | .tick_nohz_irq_exit() {
1) | .__tick_nohz_idle_enter() {
1) | .ktime_get() {
1) 0.576 us | .timebase_read();
1) 5.568 us | }
1) 0.256 us | .rcu_needs_cpu();
1) 0.192 us | .timer_clear_idle();
1) + 21.696 us | }
1) + 27.520 us | }
1) | .rcu_irq_exit() {
1) 1.024 us | .rcu_eqs_enter_common.isra.46();
1) 6.400 us | }
1) ! 285.504 us | }
1) ! 765.248 us | }
1) # 2864.576 us | }
1) # 2871.616 us | }
1) # 2877.184 us | }
