topic Hello Katya, in Analyzers

Corrupted data during finalization with Intel VTune

Alain_M_ — Wed, 01 Feb 2017 07:32:16 GMT

When lauching "Advanced Hotspots" analysis with Intel Amplifier, data finalization fails with corrupted data when loading file 1076.vtss (see attached file below). I use a CPU sampling interval of 15 ms and unlimited result size (0) When I use a CPU sampling interval of 20 ms, everything is OK, but I would like to work with more precise sampling (default value set by Intel is 1 ms)

Hello Alain,

Ekaterina_L_Intel — Thu, 02 Feb 2017 06:34:28 GMT

Hello Alain,

Thanks for reporting the issue! We are looking into the result now.

Regards, Katya

Hello Alain,

Ekaterina_L_Intel — Thu, 02 Feb 2017 06:44:00 GMT

Hello Alain,

Can you please verify a possible fix for the issue? You will need to perform below steps under Administrator account:
1. Download and unpack attached vtss.zip
2. Go to <VTune_install_dir>\bin64
3. Unload the current VTSS driver
amplxe-sepreg.exe -u
4. Copy the new vtss.sys to <VTune_install_dir>\bin64\sepdrv
3. Load the new driver
amplxe-sepreg.exe -i

4. Run the Advanced Hotspots analysis with stacks several times

Please let us know if it works? Thanks for your cooperation.

Regards, Katya

Hello Katya,

Alain_M_ — Thu, 02 Feb 2017 11:35:39 GMT

Hello Katya,

Everything seems to be better with this new driver !
I carried out several analysis with call stacks and counts and it gives me results with no more failures even when I load very large result files.
Is this modified driver reliable enough to continue my analysis ?
Nevertheless, I observe some vertical strips in Thread View (bottom part of the image in attached file).

Regards.

Alain

Hi Alain,

Ekaterina_L_Intel — Mon, 06 Feb 2017 08:39:13 GMT

Hi Alain,

The modified driver should be reliable to continue analysis.

The vertical stripes mark the time when the incoming data rate (sampling and stack data collection) exceeded the outgoing data rate (disk BW) and the driver had to stall the execution of the target app to gain more time to save the data to the disk, not to lose anything.

Regards, Katya

Hi Katya,

Munara_T_Intel — Mon, 13 Mar 2017 18:10:26 GMT

Hi Katya,

Alain has reported that he still experiences the same issue with 2017 u2 version. Is there a permanent solution for this?

Or does he need to use the vtss file you provided for future releases as well?

Thanks,

Hello,

Ekaterina_L_Intel — Thu, 16 Mar 2017 05:56:57 GMT

Hello,

The fix was included into the 2017 U2 release, so it may be another issue?
Alain, can you please provided a new "corrupted data" result collected with 2017 U2 release so we can explore the new vtss trace on our side?

Regards, Katya

Hi Katya,

Alain_M_ — Thu, 16 Mar 2017 08:20:11 GMT

Hi Katya,

Sorry for the misunderstanding but I was not aware that the fix was included into update 2 release and so far I only did my perfs analysis with update 1 with your patch. Now that I know that the fix is included into update 2, I will upgrade and redo my analysis with this latest version. I will revert back to you in case of problem.

Regards.

Alain.

Results seems to be OK with

Alain_M_ — Fri, 17 Mar 2017 16:18:07 GMT

Results seems to be OK with update 2.

Nevertheless, when I want to stop analysis by pressing STOP button, I get an error message ("Cannot process the command") : see attached file.

When I press again the stop button, than the vtss file is loaded correctly an my results are displayed after a while.

We will look into this.

Ekaterina_L_Intel — Mon, 20 Mar 2017 11:43:10 GMT

We will look into this. Thanks, Alain!

Regards, Katya