Hi,
I am using the irqsoff tracer on a (slightly old) kernel and I am seeing something like this.
As you can see, after servicing the hrtimer_interrupt, and calling irq_exit(), a softirq runs.
But the softirq (which happens to be run_timer_softirq) is being called with interrupts
disabled, - but from my understanding, interrupts are to remain enabled during softirq
operation (unless ofcourse a spinlock is shared between a softirq and an irq handler and
someone calls spinlock_irq_save).
So considering this, does the below makes sense? Thanks for any insight!
mmcqd/0-1435 0d.h1 182us : preempt_count_add <-_raw_spin_lock
mmcqd/0-1435 0d.h2 182us : enqueue_hrtimer <-__run_hrtimer
mmcqd/0-1435 0d.h2 183us : _raw_spin_unlock <-hrtimer_interrupt
mmcqd/0-1435 0d.h2 183us : preempt_count_sub <-_raw_spin_unlock
mmcqd/0-1435 0d.h1 184us : tick_program_event <-hrtimer_interrupt
mmcqd/0-1435 0d.h1 184us : clockevents_program_event <-tick_program_event
mmcqd/0-1435 0d.h1 184us : ktime_get <-clockevents_program_event
mmcqd/0-1435 0d.h1 185us : lapic_next_deadline <-clockevents_program_event
mmcqd/0-1435 0d.h1 186us : irq_exit <-smp_apic_timer_interrupt
mmcqd/0-1435 0d.h1 186us : irqtime_account_irq <-irq_exit
mmcqd/0-1435 0d.h1 187us : preempt_count_sub <-irq_exit
mmcqd/0-1435 0d..1 187us : __do_softirq <-irq_exit
mmcqd/0-1435 0d..1 188us : msecs_to_jiffies <-__do_softirq
mmcqd/0-1435 0d..1 188us : irqtime_account_irq <-__do_softirq
mmcqd/0-1435 0d..1 188us : __local_bh_disable_ip <-__do_softirq
mmcqd/0-1435 0d.s1 190us : preempt_count_add <-_raw_spin_lock_irq
mmcqd/0-1435 0d.s2 191us+: _raw_spin_unlock_irq <-run_timer_softirq
mmcqd/0-1435 0d.s1 194us : preempt_count_add <-_raw_read_lock_irqsave
mmcqd/0-1435 0d.s2 195us+: _raw_read_unlock_irqrestore <-cpufreq_cpu_get
mmcqd/0-1435 0d.s1 201us : preempt_count_add <-_raw_spin_lock_irqsave
mmcqd/0-1435 0d.s2 202us : _raw_spin_unlock_irqrestore <-cpufreq_stats_update
mmcqd/0-1435 0d.s1 203us : preempt_count_add <-_raw_spin_lock_irqsave
mmcqd/0-1435 0d.s2 203us+: _raw_spin_unlock_irqrestore <-cpufreq_stat_notifier_trans
mmcqd/0-1435 0d.s1 205us : preempt_count_add <-_raw_spin_lock_irqsave
mmcqd/0-1435 0d.s2 205us : detach_if_pending <-mod_timer_pinned
mmcqd/0-1435 0d.s2 206us : internal_add_timer <-mod_timer_pinned
mmcqd/0-1435 0d.s2 207us : __internal_add_timer <-internal_add_timer
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