Re: route cache DoS testing and softirqs

[Robert Olsson <Robert.Olsson@xxxxxxxxxxx>]

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