panic with tcp timers

[Adrian Chadd]

There's implications for RSS with how the callout system currently works.

If you don't know the RSS bucket ID of a connection in advance, you'll
create callouts on the wrong CPUs and then they're not migrated.

The initial work here did convert things over, but didn't place the
callouts in the right CPU/RSS bucket and there wasn't a mechanism to
fix this. :(

(But I'm also a firm believer of that too. I'd also finally just like
the callout system to not be tied to per-CPU queues, but also
per-RSS-bucket callout wheels so we could assign a CPU mask to a given
callout wheel and then migrating things around is just "change cpu
mask", not "change callout cpu id.")


-adrian


On 20 June 2016 at 04:00, Hans Petter Selasky <hps at selasky.org> wrote:
> On 06/20/16 12:30, Gleb Smirnoff wrote:
>>
>> What does prevent us from converting TCP timeouts to locked? To my
>> understanding it is the lock order of taking pcbinfo after pcb lock.
>
>
> I started this work:
>
> https://reviews.freebsd.org/D1563
>
> --HPS
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