Re: route cache DoS testing and softirqs

From: Robert Olsson
Date: Tue Mar 30 2004 - 18:05:10 EST



Andrea Arcangeli writes:

> He posted these numbers:
>
> softirq_count, ksoftirqd_count and other_softirq_count shows -
>
> CPU 0 : 638240 554 637686
> CPU 1 : 102316 1 102315
> CPU 2 : 675696 557 675139
> CPU 3 : 102305 0 102305
>
> that means nothing runs in ksoftirqd for Dipankar, so he cannot be using
> NAPI.
>
> Either that or I'm misreading his numbers, or his stats results are wrong.

Well we have to ask Dipankar... But I'll buy a beer if it's not on. :)

Anyway w. NAPI enabled. 2 * 304 kpps DoS flows into eth0, eth2. Flows
are 2 * 10 Millions 64 byte pkts. 32 k buckets routehash. Full Internet
routing means ~130 k routes. Linux 2.6.4 2*2.66 MHz XEON.


26: 896 0 IO-APIC-level eth0
27: 25197 0 IO-APIC-level eth1
28: 8 579 IO-APIC-level eth2
29: 10 26112 IO-APIC-level eth3

T-put is seen on output dev. eth1, eth3. So about 16% of incoming load,

eth0 1500 0 1577468 9631270 9631270 8422828 237 0 0 0 BRU
eth1 1500 0 42 0 0 0 1573355 0 0 0 BRU
eth2 1500 0 1636154 9603432 9603432 8363849 41 0 0 0 BRU
eth3 1500 0 54 0 0 0 1632274 0 0 0 BRU

And lots of
.
.
printk: 1898 messages suppressed.
dst cache overflow
printk: 829 messages suppressed.
dst cache overflow

Cheers.
--ro
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