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ext3h
Adept I

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

Re: AMD uProf: Bluescreen when combining IBS with stack sampling

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
Adept I

Re: AMD uProf: Bluescreen when combining IBS with stack sampling

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
Staff

Re: AMD uProf: Bluescreen when combining IBS with stack sampling

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.