Michael Ellerman <m...@ellerman.id.au> writes:
> Nicholas Piggin <npig...@gmail.com> writes:
>
>> Hi,
>>
>> 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:
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() {
1) | .__do_irq() {
1) | .irq_enter() {
1) 0.704 us | .rcu_irq_enter();
1) | .tick_irq_enter() {
1) 0.448 us | .tick_check_oneshot_broadcast_this_cpu();
1) 0.768 us | .ktime_get();
1) | .update_ts_time_stats() {
1) 0.256 us | .nr_iowait_cpu();
1) 5.632 us | }
1) 0.192 us | .touch_softlockup_watchdog_sched();
1) + 27.904 us | }
1) | ._local_bh_enable() {
1) 0.320 us | .__local_bh_enable();
1) 5.760 us | }
1) 1.024 us | .vtime_account_irq_enter();
1) + 55.744 us | }
1) 1.024 us | .iic_get_irq();
1) | .generic_handle_irq() {
1) | .handle_percpu_irq() {
1) | .handle_irq_event_percpu() {
1) | .__handle_irq_event_percpu() {
1) | .reschedule_action() {
1) | .scheduler_ipi() {
1) | .irq_enter() {
1) 0.640 us | .rcu_irq_enter();
1) 0.384 us | .vtime_account_irq_enter();
1) + 11.776 us | }
1) | .sched_ttwu_pending() {
1) 0.448 us | ._raw_spin_lock_irqsave();
1) | .ttwu_do_activate() {
1) | .activate_task() {
1) 0.256 us | .update_rq_clock();
1) | .enqueue_task_fair() {
1) 0.320 us | .update_curr();
1) 0.256 us |
.__compute_runnable_contrib();
1) 0.384 us | .attach_entity_load_avg();
1) 0.256 us | .__enqueue_entity();
1) 0.192 us | .hrtick_update();
1) + 30.592 us | }
1) + 41.216 us | }
1) | .wq_worker_waking_up() {
1) 0.576 us | .kthread_data();
1) 6.464 us | }
1) | .ttwu_do_wakeup() {
1) | .check_preempt_curr() {
1) 0.576 us | .resched_curr();
1) 6.272 us | }
1) + 12.224 us | }
1) + 75.904 us | }
1) 0.320 us | ._raw_spin_unlock_irqrestore();
1) + 92.736 us | }
1) | .irq_exit() {
1) 0.192 us | .idle_cpu();
1) 0.256 us | .rcu_irq_exit();
1) + 11.520 us | }
1) ! 132.032 us | }
1) ! 137.280 us | }
1) ! 142.784 us | }
1) | .add_interrupt_randomness() {
1) 0.704 us | ._raw_spin_trylock();
1) | .__mix_pool_bytes() {
1) 1.152 us | ._mix_pool_bytes();
1) 6.464 us | }
1) | .credit_entropy_bits() {
1) | .__wake_up() {
1) 0.384 us | ._raw_spin_lock_irqsave();
1) 0.256 us | .__wake_up_common();
1) 0.256 us | ._raw_spin_unlock_irqrestore();
1) + 16.384 us | }
1) 0.256 us | .kill_fasync();
1) + 27.584 us | }
1) + 49.856 us | }
1) 0.256 us | .note_interrupt();
1) ! 208.768 us | }
1) 0.448 us | .iic_eoi();
1) ! 220.352 us | }
1) ! 227.200 us | }
1) | .irq_exit() {
1) 0.128 us | .idle_cpu();
1) | .rcu_irq_exit() {
1) 0.576 us | .rcu_eqs_enter_common.isra.46();
1) 3.840 us | }
1) + 10.688 us | }
1) ! 313.024 us | }
1) ! 318.400 us | }
1) @ 960000.6 us | }
1) @ 960004.3 us | }
1) @ 960007.8 us | }
cheers
