DragonFly kernel List (threaded) for 2009-03
Re: Turn on adaptive MPSAFE for network threads, MPSAFE for IP and ARP
On Tue, Mar 10, 2009 at 12:28 AM, Matthias Schmidt
> Hi Sephe,
> * Sepherosa Ziehau wrote:
>> Hi all,
>> I plan to set following tunables by default:
>> The first three enables adaptive MPSAFE for network threads.
>> The last two enable IP and ARP MPSAFE.
>> This gives us BGL free ip forwarding path and BGL free bridge
>> forwarding path. pf is still under BGL though.
> Do you have any statistics regarding network performance? Is there a
> "visible" difference?
On my Phenom9550 (2GB memory) w/ dual port 82571EB, one direction
forwarding, packets even spreaded to each core. INVARIANTS is turned
on in the kernel config (I don't think it makes much sense to run a
system without INVARIANTS).
WIthout ipfw, BGL, ip forwarding:
~370Kpps - ~380Kpps
Without ipfw, BGL free, ip forwarding:
With ipfw default pass rule, BGL free, ip/bridge forwarding:
With ipfw 10 no matching rules + default pass rule, BGL free,
Without ipfw, BGL free, ip fast forwarding (ipflow):
~650Kpps - ~670Kpps
Without ipfw, BGL free, bridging forwarding:
For pure forwarding (i.e. no firewalling), the major bottle neck is on
transmit path (as I have measured, if you used spinlock on ifq, the
whole forwarding could be choked). Hopefully ongoing multi queue work
could make the situation much better.
Live Free or Die