dtrace/cyclic deadlock

[Andriy Gapon]

on 23/11/2010 15:26 Andriy Gapon said the following:
> on 23/11/2010 08:33 Andriy Gapon said the following:
>> I think that this is quite similar to what we do for per-CPU caches in UMA and
>> so the same approach should work here.
>> That is, as in (Open)Solaris, the data should be accessed only from the owning
>> CPU and spinlock_enter()/spinlock_exit() should be used to prevent races between
>> non-interrupt code and nested interrupt code.
> 
> Here's a patch that makes our version of cyclic.c a little bit closer to the
> upstream version whilst implementing the above idea:
> http://people.freebsd.org/~avg/cyclic-deadlock.diff
> 
> All accesses to per-CPU cyclics data are performed strictly from the corresponding
> CPUs in an interrupt or interrupt-like context.  "Upcalls" occur in event timer's
> interrupt filter and all down calls are performed via smp_rendezvous_cpus().
> 
> I will appreciate reviews and testing.

Should I wait for any pending comments?
Otherwise I am confident enough in the patch to commit it.

-- 
Andriy Gapon