Awful Slowdowns

Questions about YourKit .NET Profiler
Post Reply
stusmith
Posts: 1
Joined: Thu Feb 21, 2008 6:23 pm

Awful Slowdowns

Post by stusmith »

I've just installed YourKit for .NET on Vista x64, and it causes horrible slowdowns in all .NET applications.

I've been working on a small .NET 3.5 application that luckily prints out execution times. Having installed (but not run) YourKit, I noticed that the executions times were ten times as long. I ran YourKit, and noticed it was trying to profile all .NET applications - including the Vista sidebar!

A profiler should only try to profile applications I explicitly ask it to. Profiling every single .NET application on the system, trashing performance in the process, isn't acceptable.

Needless to say I've uninstalled your application. As it stands, it's essentially unusable on my system.
Anton Katilin
Posts: 6172
Joined: Wed Aug 11, 2004 8:37 am

Post by Anton Katilin »

The profiler _does not_ profile all applications on your system.

Instead, it _enables_ profiling, which means that it allows you to connect to any application should you need to profile it.

When such profiling-enabled application is not being profiled, there should be no overhead at all.

The described problem is a new issue. Obviously, such behavior is not normal.

Could you please send logs located in <user home dir>/.yjp/log to [email protected]

I hope they will help to find out the reason why something goes wrong on your system.
Tobbe
Posts: 72
Joined: Thu Feb 21, 2008 11:08 am

Post by Tobbe »

Have a collegue that reported the same thing on 304 build. Even when yourkit wasnt running. He uninstalled yourkit and problem went away.

We are runing Quade Core on XP 32
Anton Katilin (YourKit)
Posts: 157
Joined: Wed Aug 15, 2007 9:09 pm

Post by Anton Katilin (YourKit) »

Have a collegue that reported the same thing on 304 build. Even when yourkit wasnt running. He uninstalled yourkit and problem went away.
Have you experienced same problem on your machine?

What OS was installed on your collegue's machine?
What was the version of .NET framework?

We'd appreciate if you could send logs located in <user home dir>/.ynp/log to [email protected] (from the collegue's machine or from yours if you experienced that problem too).
Tobbe
Posts: 72
Joined: Thu Feb 21, 2008 11:08 am

Post by Tobbe »

My collegue dont have time right now, and i guess that his trial license has/will expired also. We have the same setup:
- XP 32
- Quad Core
- 4Gb RAM

Have you experienced same problem on your machine?
Cant say for sure, however sometimes profiling slowsdown the profiled application considerably. We are talking almost a minute just to logon into the application.

Logs are sent as requested
Tobbe
Posts: 72
Joined: Thu Feb 21, 2008 11:08 am

Post by Tobbe »

Im confirming this for my computer also. Uninstalling yourkit made drastic .NET preformance gains.

Yourkit version 304 on .NET 2.0 applications not good
Anton Katilin
Posts: 6172
Joined: Wed Aug 11, 2004 8:37 am

Post by Anton Katilin »

It seems that the slowdown was caused by a periodically
happening crash in CPU sampler thread. Each time it happened, it was
logged with full detail.

Could you please try this build (3.0.4a):
http://www.yourkit.com/dotnet/download/ ... r-.NET.exe

Changes over 3.0.4:
- we hope we fixed the reason of that crash so it should not happen
again
- also we have changed error processing and logging such that it will stop
logging same errors after several occurrences
Tobbe
Posts: 72
Joined: Thu Feb 21, 2008 11:08 am

Post by Tobbe »

Sorry to say that 304a version did nothing for computer.

Its visually noticable if you toggle between maximized/restore size of a application containing a gridview (docked full) with data. Yourkit uninstalled there is no visuall lag or slowdown. But installed there is. You can se how the .net form struggles to repaint the grid. Its strange is Yourkit allways running in background (service) because it doent matter if im running it or not.
Anton Katilin
Posts: 6172
Joined: Wed Aug 11, 2004 8:37 am

Post by Anton Katilin »

Could you please:

- remove all files in <user home>/.ynp/log
- uninstall previously installed builds of the profiler
- if uninstaller asks to reboot, please reboot
- install 3.0.4a
- if you notice the slowdown, please send all logs from <user home>/.ynp/log to [email protected]

Also, please do the following in the Welcome screen:

- open "Edit applications that should not be profiled". What is its content?
- a screenshot of the Welcome screen depicting running applications would be much appreciated
- what is the content of "Edit application startup options"?
Anton Katilin
Posts: 6172
Joined: Wed Aug 11, 2004 8:37 am

Post by Anton Katilin »

Its strange is Yourkit allways running in background (service) because it doent matter if im running it or not.
It is not running in background. When you don't preform profiling, there should be no overhead. There is a problem (a bug) which causes the slowdown in your case. I'm asking you about all the detail in order to find where the problem is and fix it.
Tobbe
Posts: 72
Joined: Thu Feb 21, 2008 11:08 am

Post by Tobbe »

Logs and screens sent. I followed your steps and still experience the slowdown.
Anton Katilin
Posts: 6172
Joined: Wed Aug 11, 2004 8:37 am

Post by Anton Katilin »

Thank you for the logs.

There is no crash in them.

Could you please try if the following changes anything:

1. On the Welcome screen, set "Profiler Status" to "Enable profiling with no CPU tracing".

Note that the settings affect newly started applications, so restart of already running application is needed to see the effect of changing the settings.

2. Similar experiment with "Disable profiling"
Tobbe
Posts: 72
Joined: Thu Feb 21, 2008 11:08 am

Post by Tobbe »

Im not sayin that it crashes my computer im saying it slows it down. The 403a really put my computer to the test. The cpu fan spun on 100% of its speed and aspnet_wp.exe (process i profiled) used minimum of 25% CPU time peeaked at 99% system started to freze/unfreze almost unable to work.

This on the configuration i sent you.
1. On the Welcome screen, set "Profiler Status" to "Enable profiling with no CPU tracing".
2. Similar experiment with "Disable profiling"
Both did the trick helped with the slowdown. BUT if i return to my previous configuration and close yourkit it is still profiling in background because the slow down is there!



[/quote]
Anton Katilin
Posts: 6172
Joined: Wed Aug 11, 2004 8:37 am

Post by Anton Katilin »

In this case you can use "Enable profiling with no CPU tracing".

CPU sampling can be used instead of tracing in many cases.

Alternatively, turn full profiling capabilities profiling on before you start certain application to profile. When the application started, turn that mode off.

.NET framework architecture requires that method tracing events are enabled on application. If not enabled on startup, tracing is unavailable.
Tobbe
Posts: 72
Joined: Thu Feb 21, 2008 11:08 am

Post by Tobbe »

Im confused...

If yourkit is started and profile is enabled...do every .NET application I start get profiled automatic? Or just the once I select in "Monitor Applications"?

If not, this is no good, we have alot of small .NET applikations that helps us in our daily work. I dont want to add/remove/add/remove/etc them from the exclusion list every time i want to profile a specific applikation.

As stated by topic creator
A profiler should only try to profile applications I explicitly ask it to. Profiling every single .NET application on the system, trashing performance in the process, isn't acceptable.
Post Reply