[hpsdr] Observations on the new HPSDR firmware/PowerSDR

[Bill Tracey]

Hi Dan,

Interesting observations -- will have to look 
into it.  How long does it take it to degrade to 
where you're hearing bands and pops?  I've had 
mine running listening to a tone for the  last 30 
mins or so and haven't heard it glitch.   I'm on 
a Quad Core on Vista so have a bit different setup than you do.

A time oriented degradation leads me to the 
perhaps garbage collection issues, but I did not 
think any of our main path (audio buffers) stuff 
relied on garbage collection.

How are grabbing the call stacks - Process Explorer?

Looks like it might be time to learn a bit on .NET profiling.

Cheers

Bill (kd5tfd)

At 04:52 PM 5/30/2009, Dan Quigley wrote:
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>I hope this helps

>
>On my WinXP box running on an Intel 2.1Ghz duo 
>core with 3GB of ram, PowerSDR works fine (read 
>great!) for a “while” then the receive function 
>gradually starts degrading (drop outs/pops etc) 
>until audio eventually stops.  CPU also rises 
>with the incidence of popping/drop outs.  How 
>long it takes to degrade appears to be related 
>to audio buffer size and sample rate 
>settings.  The higher the sample rate the less 
>amount of time it takes for performance to 
>degrade.   Transmitting also appears to 
>accelerate the time it takes to degrade.
>
>Good performance returns when you  restart 
>PowerSDR (first waiting for the previous 
>instance to unload, which can take a while.
>
>When running fine (e.g. no drop outs) , the 
>thread that consumes most of the CPU cycles in 
>the PowerSDR.exe process has this call 
>stack  (or one very similar), at 192K bandwidth.
>
>Thread 5-11% cpu
>ntkrnlpa.exe!NtBuildNumber+0x43
>ntkrnlpa.exe!MmIsDriverVerifying+0xbb0
>ntkrnlpa.exe!MmIsDriverVerifying+0x1492
>ntkrnlpa.exe!PoShutdownBugCheck+0x39e9
>ntkrnlpa.exe!KeSynchronizeExecution+0x30c
>ntdll.dll!KiFastSystemCallRet
>KERNEL32.dll!WaitForMultipleObjects+0x18
>pthreadVC.dll!pthread_exit+0x111
>
>Once performance degrades and drop outs begin to 
>occur frequently.  This thread and call stack 
>floats quickly to the top of the sorted by cpu 
>list.  Then stays at the top.  This thread jumps 
>to  50% cpu  when you close PowerSDR and stays 
>there for a minute or so.  When it eventually 
>terminates, PowerSDR is unloaded from memory:
>
>Thread 34% cpu
>Stack:
>ntkrnlpa.exe!NtBuildNumber+0x43
>ntkrnlpa.exe!MmIsDriverVerifying+0xbb0
>hal.dll!HalClearSoftwareInterrupt+0x342
>DttSP.dll!SetKeyerSampleRate+0x27c8
>DttSP.dll!PolyPhaseFIRF+0x28ca
>
>When the system has totally degraded this thread stays at 15% cpu
>Thread 15% cpu
>Stack:
>ntkrnlpa.exe!NtBuildNumber+0x43
>ntkrnlpa.exe!MmIsDriverVerifying+0xbb0
>ntkrnlpa.exe!MmIsDriverVerifying+0x1492
>ntkrnlpa.exe!PoShutdownBugCheck+0x3702
>ntkrnlpa.exe!KeSynchronizeExecution+0x30c
>ntdll.dll!KiFastSystemCallRet
>KERNEL32.dll!WaitForSingleObject+0x12
>libusb0.dll!usb_set_debug+0x266
>libusb0.dll!usb_reap_async+0xf
>libusb0.dll!usb_bulk_write+0x1e
>JanusAudio.dll!OzyBulkWrite+0x21



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