[Differential] [Commented On] D1711: Changes to the callout code to restore active semantics and also add a test-framework and test to validate thecallout code (and potentially for use by other tests).

[hiren (hiren panchasara)]

hiren added a comment.

>>! In D1711#61, @hselasky wrote:
> Hi,
> 
> There is only one or two likely consumers of callout_init_rw() at the present moment, and one of them is:
> 
> ./netinet6/nd6.c:		canceled = callout_stop(&ln->ln_timer_ch);
> ./netinet6/nd6.c:			canceled = callout_reset(&ln->ln_timer_ch, INT_MAX,
> ./netinet6/nd6.c:			canceled = callout_reset(&ln->ln_timer_ch, tick,
> ./netinet6/in6.c:	callout_init_rw(&lle->base.ln_timer_ch, &lle->base.lle_lock,
> 
> hiren: Is this box configured for IPv6 ?

No, not for panic #3. But as I replied to rrs's comment, I need to first make sure what tree we are running and if we are missing critical fixes from stable-10.

> 
> static void
> in_lltable_free(struct lltable *llt, struct llentry *lle)
> {
>         LLE_WUNLOCK(lle);
>         LLE_LOCK_DESTROY(lle);
>         free(lle, M_LLTABLE);
> }
> 
> ln_lltable_free() does not drain the callout associated with it and I am not sure if we have a sleeping context for that. Even if the refcount is zero, it doesn't mean that the callback is finished using the RW mutex.
> 
> This is another example where we really need a "callout_drain_async_function()".

REVISION DETAIL
  https://reviews.freebsd.org/D1711

To: rrs, gnn, rwatson, lstewart, jhb, kostikbel, hselasky, adrian, imp, sbruno
Cc: hiren, jhb, kostikbel, emaste, delphij, neel, erj, freebsd-net