[jitsi-dev] Re: Analysis to find cause of Echo Canceller Failing For Latency


#1

Hi Lyubomir,

could you please give me a hint on how to handle Oprofile? I managed to start the daemon but couldn't find any option to turn on Java profiling. Actually I couldn't get it to profile anything despite checking out this one: http://oprofile.sourceforge.net/doc/controlling.html
What am I missing?

Thank you
Conrad

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----- Ursprüngliche Nachricht -----
Von: Lyubomir Marinov
Gesendet: 26.02.11 11:23 Uhr
An: dev@jitsi.java.net
Betreff: [jitsi-dev] Re: Analysis to find cause of Echo Canceller Failing For Latency

Hi Conrad, I don't immediately see a problem in the two thread dumps that you've attached. I'd personally suggest creating and analyzing system-wide profiles, for example, created with OProfile (with Java profiling enabled). Regards, Lyubomir

Bitte antworten an/Please reply to/Por favor conteste a:
conrad_b@iname.com


#2

could you please give me a hint on how to handle Oprofile? I managed to
start the daemon but couldn't find any option to turn on Java profiling.

As http://oprofile.sourceforge.net/doc/setup-jit.html says, you'll
need OProfile built with the --with-java option. I've only used it on
Ubuntu which does not provide an OProfile package built with the
--with-java option so I build OProfile myself in order to enable Java
profiling.

Actually I couldn't get it to profile anything despite checking out this
one: http://oprofile.sourceforge.net/doc/controlling.html
What am I missing?

You use opcontrol to setup and start the profiling. Then you wait for
the profiled (part of the) application to execute (as much as you
want). When you want to look at and analyse the results, you have to
tell opcontrol --dump i.e. to force a flush of the collected profiling
data.

You use opreport to look at and analyze the collected profiling data.
So you'll likely want to read
http://oprofile.sourceforge.net/doc/results.html.

···

On Tue, Mar 1, 2011 at 10:48 PM, Conrad Beckert <conrad_videokonferenz@gmx.de> wrote:


#3

Hi Lyubomir,

I've only used it on
Ubuntu which does not provide an OProfile package built with the
--with-java option so I build OProfile myself in order to enable Java
profiling.

Well, then I would have to build it myself as well. I seem to have the actual version for Lucid which states to have the JIT - but obviously not.

I'll give it a try next week.

You use opcontrol to setup and start the profiling. Then you wait for
the profiled (part of the) application to execute (as much as you
want). When you want to look at and analyse the results, you have to
tell opcontrol --dump i.e. to force a flush of the collected profiling
data.

I did this and had an empty protocoll. Perhaps something is wrong with the packages in Ubuntu.

My test case was to call my Asterisk echo test app - which works fine. Latency is low and there is no audio feed back from the speakers since the echo canceller works fine (even when I point the mike to the speakers)

Turning the video on causes a short feed back for a couple of seconds but then the echo the canceller works again as usual. Latency is a bit higher though.

Switching from video to (partial) Desktop Streaming still doesn't matter, but then returning back to video is too much: The echo canceller stops working and sometimes not even closing the call helps to bring it back. (restarting Jitsi, of course, does)

You might want to try this? It is probably reproducable on other hardware as well. I could give you access to my Asterisk. I'll be able to dedicate an evening to building OProfile and doing the tests probably sometime next week.

Greetings
Conrad