diff options
| -rw-r--r-- | sys/kern/kern_poll.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/sys/kern/kern_poll.c b/sys/kern/kern_poll.c index 4101cdf..a197bc0 100644 --- a/sys/kern/kern_poll.c +++ b/sys/kern/kern_poll.c @@ -195,6 +195,12 @@ init_device_poll(void) /* * Hook from hardclock. Tries to schedule a netisr, but keeps track * of lost ticks due to the previous handler taking too long. + * Normally, this should not happen, because polling handler should + * run for a short time. However, in some cases (e.g. when there are + * changes in link status etc.) the drivers take a very long time + * (even in the order of milliseconds) to reset and reconfigure the + * device, causing apparent lost polls. + * * The first part of the code is just for debugging purposes, and tries * to count how often hardclock ticks are shorter than they should, * meaning either stray interrupts or delayed events. @@ -217,10 +223,11 @@ hardclock_device_poll(void) prev_t = t; if (pending_polls > 100) { - /* too much, assume it has stalled */ + /* + * Too much, assume it has stalled (not always true + * see comment above). + */ stalled++; - printf("poll stalled [%d] in phase %d\n", - stalled, phase); pending_polls = 0; phase = 0; } |
