diff options
| -rw-r--r-- | sys/kern/kern_intr.c | 41 |
1 files changed, 33 insertions, 8 deletions
diff --git a/sys/kern/kern_intr.c b/sys/kern/kern_intr.c index fcf6f6655a49..add11621df19 100644 --- a/sys/kern/kern_intr.c +++ b/sys/kern/kern_intr.c @@ -72,6 +72,12 @@ static void ithread_update(struct ithd *); static void ithread_loop(void *); static void start_softintr(void *); +static int intr_storm_threshold = 500; +TUNABLE_INT("hw.intr_storm_threshold", &intr_storm_threshold); +SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RW, + &intr_storm_threshold, 0, + "Number of consecutive interrupts before storm protection is enabled."); + u_char ithread_priority(enum intr_type flags) { @@ -488,12 +494,15 @@ ithread_loop(void *arg) struct intrhand *ih; /* and our interrupt handler chain */ struct thread *td; struct proc *p; + int count, warned; td = curthread; p = td->td_proc; ithd = (struct ithd *)arg; /* point to myself */ KASSERT(ithd->it_td == td && td->td_ithd == ithd, ("%s: ithread and proc linkage out of sync", __func__)); + count = 0; + warned = 0; /* * As long as we have interrupts outstanding, go through the @@ -522,6 +531,24 @@ ithread_loop(void *arg) * another pass. */ atomic_store_rel_int(&ithd->it_need, 0); + + /* + * If we detect an interrupt storm, pause with + * the source masked for 1/10th of a second. + */ + if (intr_storm_threshold != 0 && count >= + intr_storm_threshold) { + if (!warned) { + printf( + "Interrupt storm detected on \"%s\", throttling interrupt source\n", + p->p_comm); + warned = 1; + } + tsleep(&count, td->td_priority, "throttle", + hz / 10); + count = 0; + } else + count++; restart: TAILQ_FOREACH(ih, &ithd->it_handlers, ih_next) { if (ithd->it_flags & IT_SOFT && !ih->ih_need) @@ -547,23 +574,21 @@ restart: if ((ih->ih_flags & IH_MPSAFE) == 0) mtx_unlock(&Giant); } + if (ithd->it_enable != NULL) + ithd->it_enable(ithd->it_vector); } + WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); + mtx_assert(&Giant, MA_NOTOWNED); /* * Processed all our interrupts. Now get the sched * lock. This may take a while and it_need may get * set again, so we have to check it again. */ - WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); - mtx_assert(&Giant, MA_NOTOWNED); mtx_lock_spin(&sched_lock); if (!ithd->it_need) { - /* - * Should we call this earlier in the loop above? - */ - if (ithd->it_enable != NULL) - ithd->it_enable(ithd->it_vector); - TD_SET_IWAIT(td); /* we're idle */ + TD_SET_IWAIT(td); + count = 0; CTR2(KTR_INTR, "%s: pid %d: done", __func__, p->p_pid); mi_switch(SW_VOL); CTR2(KTR_INTR, "%s: pid %d: resumed", __func__, p->p_pid); |