[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).

[rrs (Randall Stewart)]

rrs added a comment.

Imp:

Ok I have spent a bit of time puzzling this out. First I was mistaken, the callouts being run
are either arptimer or nd6timer(function name not right). These are not using giant but
the passed in lle structure rw_lock. 

We need to adjust these so that they check they:
1) get the lock (since the callout system would no longer lock for them the rw_lock)
2) Check the pending bit.. if its set some other place as restarted the callout (there are several
   places this can happen from).
3) Don't check the !callout_active() flag, since this would mean its not been rescheduled and 
    it actually was cleared by the lle_table_flush (wrong function name here) function, in there
    its watching the return of the callout (its where the crash was from). So instead now since 
    the "callout can't be stopped" it returns 0 (not lowering the reference) even though the callout
    can't be stopped, it will have removed the active bit which.. so if we returned here we would
    leak the memory leaving the reference up, so instead we go ahead and finish processing the callout
    doing the reference lowering and removal.

Its a bit odd from the normal way you do it but I think it will work fine.

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

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