Re: [net-next PATCH v2 0/8] Add busy poll support for epoll

From: Eric Dumazet
Date: Thu Mar 23 2017 - 18:49:40 EST


On Thu, Mar 23, 2017 at 3:38 PM, Alexander Duyck
<alexander.duyck@xxxxxxxxx> wrote:
> On Thu, Mar 23, 2017 at 3:07 PM, Alexei Starovoitov

>> it all sounds awesome, but i cannot quite visualize the impact.
>> Can you post some sample code/minibenchmark and numbers before/after?
>>
>> Thanks!
>>
>
> Anything specific you are looking for? I can probably work with our
> team internally to setup the benchmark in the next day or so.
>
> I've been doing most of my benchmarking at my desk with sockperf with
> just one thread and multiple sockets and seeing some modest savings
> with my round trip times dropping from something like 18 microseconds
> on average to 8 microseconds for ping-pong tests.

Same reduction for me, on 1000/1000 bytes RPC.

26 usec -> 16 usec per transaction

(If you use sockperf, beware that it displays half round trips)

Also note that the gains also depends on how the interrupt mitigation
parameters are set.