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  • Question

  • Hi,

    I am a novice in using xperf and I have several questions:

    1. I use xperf with both PROFILE and CSWITCH providers open on NT kernel logger. I notice there is a significant difference between the graphs "cpu sampling by cpu" and "cpu usage by cpu", I can assume what is the reason for that difference, so I am using the latter graph since it seems to me more accurate. The problem is that when I do summary table I can't aggregate the usage by module since there is no module column as opposed to the graph cpu usage by sampling. Am I missing something ? Is there a way to see the usage by module in the second graph ?

    2. When looking at the summary table from graph  "CPU usage by process" which I assume gets its data from CSWITCH and not from PROFILE, I can't tell how much time each process spent on each CPU (on a multi core CPU)  - there is no CPU column. How can I retrieve this information.

    3. Do the different usage graphs takes into account the cpu scaling (when the clock frequency is dynamically changing) when they calculate CPU utilization ?

    Thanks

    Tuesday, August 9, 2011 12:12 PM

All replies

  • Hi,

    for 1)

    My expirions around this issue is the following assumption:

     

    If this is not the case I would use the Symbols function and check the CPU sampling by thread.   If this is not the case I would use the Symbols function and check the CPU sampling by thread.

    And this allow you to check and analyze in detail the cpu weight.
    And in all cases with "invisible" cpu activity at the taskmanager --> i found them by thread.

     

    About Q2)

    I had the same wish in the past. And I dump my etl and export the information. The cool thing was that I get the result as csv. And I just copy paste the used cpu kernel information and use the auto summarize function :)
    I found this trick at the nice video from the WPT product manager live demo at Channel 9.

    Q3) I'm afraid, I'm not sure what you mean with this :(.

    • Proposed as answer by RPA601SG Sunday, September 18, 2011 8:40 AM
    Tuesday, August 23, 2011 8:45 PM