[CFT] SMP-friendly pf

Chris Buechler cmb at pfsense.org
Sat Jun 9 07:15:07 UTC 2012

On Fri, Jun 8, 2012 at 2:17 AM, Gleb Smirnoff <glebius at freebsd.org> wrote:
>  Hello, networkers!
>  [net@ in Cc, but further discussion should go on pf@]
>  As you already probably know, or some may be don't yet know, the pf(4)
> subsystem in FreeBSD is currently working under a single mutex. This mutex
> is acquired right at the beginning of any packet processing, and is dropped
> at the end. While one thread is in pf(4) all other threads are blocked on
> that mutex.
>  Meanwhile modern computers are getting more and more cores, and modern
> network cards getting more MSI interrupts, each serviced by a separate kernel
> thread in FreeBSD. So the single pf lock, which I call "the pf Giant" :), is
> getting a point of hard contention.
>  Three and a half months ago I've started on a project "SMP-friendly pf",
> which recently have entered alpha stage. As you see from the subject of this
> mail, this is call for testing.
>  Willing to test?

Absolutely. Are there any particular areas specifically that you would
like some testing focus on? Obviously testing everything is needed to
ensure nothing is broken, and I'm definitely interested in doing some
performance comparisons on SMP and non-SMP hardware. But not sure what
areas you've already focused on, and what areas you feel need more
testing focus than others, if any.

Appreciate your work on this!


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