2013-04-10 17:55:53

by Luis R. Rodriguez

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Subject: Jitter and latency benchmarks with netlink / nl80211

Curious if anyone has worked on latency and jitter benchmarks in using
netlink, specifically with nl80211. Has anyone benchmarked this? Ben,
have you? If not for nl80211 perhaps this has been done before for
other netlink families?

Luis


2013-04-10 17:59:18

by Ben Greear

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Subject: Re: Jitter and latency benchmarks with netlink / nl80211

On 04/10/2013 10:55 AM, Luis R. Rodriguez wrote:
> Curious if anyone has worked on latency and jitter benchmarks in using
> netlink, specifically with nl80211. Has anyone benchmarked this? Ben,
> have you? If not for nl80211 perhaps this has been done before for
> other netlink families?

You mean timing related to netlink configuration/report requests?

We have lots of ways to measure wifi packet throughput latencies
and jitter (to/from userspace and/or to/from pktgen), but it doesn't use
netlink....

Thanks,
Ben

--
Ben Greear <[email protected]>
Candela Technologies Inc http://www.candelatech.com


2013-04-10 18:06:02

by Luis R. Rodriguez

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Subject: Re: Jitter and latency benchmarks with netlink / nl80211

On Wed, Apr 10, 2013 at 10:59 AM, Ben Greear <[email protected]> wrote:
> On 04/10/2013 10:55 AM, Luis R. Rodriguez wrote:
>>
>> Curious if anyone has worked on latency and jitter benchmarks in using
>> netlink, specifically with nl80211. Has anyone benchmarked this? Ben,
>> have you? If not for nl80211 perhaps this has been done before for
>> other netlink families?
>
>
> You mean timing related to netlink configuration/report requests?

Yes.

> We have lots of ways to measure wifi packet throughput latencies
> and jitter (to/from userspace and/or to/from pktgen), but it doesn't use
> netlink....

Not looking for latency / jitter for 802.11, but for the core nl80211 messages.

Luis

2013-04-10 18:10:10

by Ben Greear

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Subject: Re: Jitter and latency benchmarks with netlink / nl80211

On 04/10/2013 11:05 AM, Luis R. Rodriguez wrote:
> On Wed, Apr 10, 2013 at 10:59 AM, Ben Greear <[email protected]> wrote:
>> On 04/10/2013 10:55 AM, Luis R. Rodriguez wrote:
>>>
>>> Curious if anyone has worked on latency and jitter benchmarks in using
>>> netlink, specifically with nl80211. Has anyone benchmarked this? Ben,
>>> have you? If not for nl80211 perhaps this has been done before for
>>> other netlink families?
>>
>>
>> You mean timing related to netlink configuration/report requests?
>
> Yes.

No, I haven't bothered to do this... The way we use netlink is
mostly asynchronous..ie we just listen for events and process them
as they come in. Most of our configuration would be driven through 'iw',
'wpa_supplicant', 'ip', etc, and much of our stats gathering is through
the ethool get-stats API.

I would imagine any latency would be highly dependent on other applications
taking RTNL (for instance, creating/deleting lots of virtual stations,
mac-vlans, ip-address changes, etc).

Thanks,
Ben

--
Ben Greear <[email protected]>
Candela Technologies Inc http://www.candelatech.com