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Server Gurus Discussions

ext3h
Journeyman III
‎06-18-2018 07:57 AM

AMD uProf: Bluescreen when combining IBS with stack sampling

Currently running Windows 18.03 on a Threadripper 1920X based platform.

The combination of IBS with "kernel and user mode" stack samplingin any GUI application reliably results in a bluescreen after a few seconds for me:

DRIVER IRQL NOT LESS OR EQUAL in AMDCpuProfiler.sys

(This problem isn't actually unique to uProf. Older versions of VTune had the very same problem, that performance counters would trigger stack traces at illegal times, resulting in the very same bluescreen.)

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3 Replies
mgbaskar
Staff
Staff
‎06-19-2018 12:30 AM

Hi,

We will work on this issue to get it fixed. In the meantime,

  1. Can you please provide the output "AMDuProfCLI.exe info --system"
  2. If the callstack sampling is disabled, do you observe this issue?
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ext3h
In response to mgbaskar
Journeyman III
‎06-19-2018 10:22 AM 

CPU Info:
        AMD Cpu: Yes
        Family: 0x17
        Model: 0x1
        Stepping: 0x1
        Local APIC: True
        SMT Enabled: True
        Die Count (per socket): 2
        Thread Count (per socket): 24
        Thread Count (per CCX): 6
        Thread Count (per core): 2
PERF Features:
        Core PMC Available: True
        L3 PMC Available: True
        DF PMC Available: True
        PERF TS Available: False
IBS Features:
        IBS Available: True
        Ibs FetchCtlExtd Available: True
        Ibs ExtCount Available: True
        Ibs Dispatch Available: True
        Ibs BrTgtAddr Available: True
        Ibs OpData4 Available: False
RAPL, CEF Features:
        RAPL Available: True
        APERF & MPERF Available: True
        Read Only APERF & MPERF Available: True
        IRPERF Available: True
        HW P-State Control Available: True
Hypervisor Features:
        Hypervisor: False

The bluescreens do not occur with sampling turned off, or sampling limited to user mode. (At least I couldn't reproduce them at all with sampling turned of entirely. Haven't tested user mode only sampling extensively.)

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mgbaskar
Staff
In response to ext3h
Staff
‎06-20-2018 10:59 PM

We too observed the same thing, bluescreen does not occur when either call-stack sampling is turned off or only the user mode call-stack sampling is turned on. We are working on the fix.