Performance problem

Questions about YourKit .NET Profiler
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johannd
Posts: 4
Joined: Thu Nov 05, 2009 5:55 pm

Performance problem

Post by johannd »

Hi,

YourKit profiler has a very interesting and impressive list of features. That it supports sampling-based profiling caught my attention, as most .NET profilers tend to have a rather high overhead.

However, it seems that YourKit has terrible performance on my machine at work. I have not tried it on other computers, I might give it a try at home.
The computer is running Windows XP 32 bit and has 2.7 GB of memory.

I start the application that we are developing while YourKit is running and has "Enable profiling in all .NET applications" checked.
Our application uses IronPython to run plug-ins, and is written in C# and F#.
CPU profiling is not started, stack telemetry isn't started, object allocation recording is not started. If I am correct, there should be close to no overhead in this setting, right?

However, our application then runs extremely slow, easily over 10x slower. Using perfmon I can see that the application spends 80% or more of its time in garbage collection, which it normally does not.

Is there something wrong?
Anton Katilin
Posts: 6172
Joined: Wed Aug 11, 2004 8:37 am

Re: Performance problem

Post by Anton Katilin »

Hello,

There should be no such overhead.

Do you use the latest version 4.5.4?

Do you have CPU tracing enabled? If yes, please turn it off because tracing can add significant overhead. After you change the settings, the running applications should be restarted. To ensure the settings are applied, please restart the machine.

If this does not help, please send log files located in <user home>\.ynp\log to [email protected]

Best regards,
Anton
johannd
Posts: 4
Joined: Thu Nov 05, 2009 5:55 pm

Re: Performance problem

Post by johannd »

I am using version 4.5.4, and cpu tracing is not enabled. I confirm that the slowdown is still there, even though I never actually started recording.

Log files were sent to support.
Vladimir Kondratyev
Posts: 1624
Joined: Tue Aug 10, 2004 7:52 pm

Re: Performance problem

Post by Vladimir Kondratyev »

Is allocation recording enabled? If so, please try to disable it and restart your application.

How many threads does your application has?
johannd
Posts: 4
Joined: Thu Nov 05, 2009 5:55 pm

Re: Performance problem

Post by johannd »

No, I did not have allocation recording turned on.
The application uses at most two threads.
johannd
Posts: 4
Joined: Thu Nov 05, 2009 5:55 pm

Re: Performance problem

Post by johannd »

I have tried on another computer (also with Windows XP), same problem. I ran the same application.
Vladimir Kondratyev
Posts: 1624
Joined: Tue Aug 10, 2004 7:52 pm

Re: Performance problem

Post by Vladimir Kondratyev »

Please upload the application which reproduce the problem to our write-only FTP server. Here is the connection parameters:

ftp://upload.yourkit.com/pub/
user ftp
empty password

You can also sent it us by e-mail.

Please note, that we need just EXE file (without debug information, PDB, etc)
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