Re: [Bug #11308] tbench regression on each kernel release from 2.6.22 -> 2.6.28

Eric Dumazet
2008-11-21T18:19:39Z

Eric Dumazet a écrit :
> Christoph Lameter a écrit :
>> AIM9 results:
>> TCP UDP
>> 2.6.22 104868.00 489970.03
>> 2.6.28-rc5 110007.00 518640.00
>> net-next 108207.00 514790.00
>>
>> net-next looses here for some reason against 2.6.28-rc5. But the numbers
>> are better than 2.6.22 in any case.
>>
>
> I found that on current net-next, running oprofile in background can
> give better bench
> results. Thats really curious... no ?
>
>
> So the single loop on close(socket()), on all my 8 cpus is almost 10%
> faster if oprofile
> is running... (20 secs instead of 23 secs)
>

Oh well, thats normal, since when a cpu is interrupted by a NMI, and
distracted by oprofile code, it doesnt fight with other cpus on dcache_lock
and other contended cache lines...