cs collector wmi_cs_logical_processors metric reports false data

[1sttec]

On two test desktops the cs collector wmi_cs_logical_processors metric returns 0. On a test server it returns 65535. Please advise.

version: 0.16.0

[1sttec]

systeminfoapi is using GetSystemInfo (lpSysteminfo) but doc here https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/ns-sysinfoapi-system_info says to use GetLogicalProcessorInformation for logical core count instead of GetSystemInfo.dwNumberOfProcessors

...
dwNumberOfProcessors
The number of logical processors in the current group. To retrieve this value, use the GetLogicalProcessorInformation function.
...

[carlpett]

@benridley @retryW any input?

[carlpett]

@1sttec Thanks for that extra bit of info! What versions of Windows are you testing on?

[1sttec]

Server 2019 = 0
Server 2016 = 0
Server 2012 R2 = 65535
Win 7 & 10 = 0

[benridley]

Thanks @carlpett and @1sttec!

Apologies for this, looks like one of the struct fields was incorrectly sized, so when accessing them Go would be reading the wrong memory.

I've created a PR here to fix the issue: #788

[benridley]

@1sttec the fix has been merged to master now. I've tested this on a 2016 machine and it worked ok, but I'm curious how it'll go on your machines since they were getting different values. If you get a chance to test please do so and let us know. Cheers!

[1sttec]

It appears windows_cs_logical_processor is now reporting sockets * cores but not the true logical processors # which would include those available via hyper-threading.

[benridley]

Thanks @1sttec, seems like this might be a consequence of the function we use. I found this which suggests similar problems with our underlying info.

I'll try converting the metric to use the function specified in that article which will hopefully report the correct values.

[benridley]

Hi @1sttec, can you please try building my branch here and seeing if it reports the correct CPU count for you?

It's looking good on my windows machine, but so was the old way - So I just want to make sure. Thank you !

[github-actions]

This issue has been marked as stale because it has been open for 90 days with no activity. This thread will be automatically closed in 30 days if no further activity occurs.