High idle cpu

[adrian]

Hello all,

I've noticed this in the past and I've finally just decided to actually vocialise this issue. When idle (movie is on screen but paused) I've noticed that VLC will have an abnormally high CPU (5-10%). It's not doing anything but just waiting, so I would expect that it would have a idle CPU of 0 to mayby 0.5%. So, what it is doing? Some sort of spin lock?

I've got some dump files of the issue (three taken within 10 seconds of each other), if that helps. Version that I'm using is 3.0.8 Ventinari jenkins@8a458393186d on Windows 8.1. Looking at the threads using Process Explorer, the following is the call stack of the thread eating the CPU:

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ntoskrnl.exe!KeSynchronizeExecution+0x2106 ntoskrnl.exe!KeWaitForMultipleObjects+0x135e ntoskrnl.exe!KeWaitForMultipleObjects+0xdd9 ntoskrnl.exe!KeWaitForMutexObject+0x373 ntoskrnl.exe!KeStallWhileFrozen+0x1feb ntoskrnl.exe!__misaligned_access+0x13fd ntoskrnl.exe!KeWaitForMultipleObjects+0x152f ntoskrnl.exe!KeWaitForMultipleObjects+0xdd9 ntoskrnl.exe!InitializeSListHead+0xbc7 ntoskrnl.exe!EtwRegister+0x212 ntoskrnl.exe!_setjmpex+0x6553 wow64cpu.dll!TurboDispatchJumpAddressEnd+0x598 wow64cpu.dll!TurboDispatchJumpAddressEnd+0x46e wow64.dll!Wow64LdrpInitialize+0x23a wow64.dll!Wow64LdrpInitialize+0x172 ntdll.dll!LdrInitializeThunk+0x12b ntdll.dll!LdrInitializeThunk+0xe ntdll.dll!NtWaitForAlertByThreadId+0xc KERNELBASE.dll!SleepConditionVariableCS+0x20 libvlccore.dll!vlc_rand_bytes+0xa20

Hmmmm, that's odd. The last line (thread execution point) is different. When I first made a copy to see if it was spinning in the same place, that line was:

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KERNELBASE.dll!InitOnceExecuteOnce+0x17

Is that relevant?

Restarting vlc results in the same issue, so it is very reproducible. If I've not not paused a playing a video, i.e. I'm looking at the playlist, I get an expected CPU profile close to 0%.

I don't always finish watching a video, but would like to continue where I left off, so pausing it is a good option. I've also noticed that the continue from last place I stopped is kinda flaky (can lose its spot easily) so that isn't really an option.

Thanks for any help in advance.

A

[Hitchhiker]

It could be due to a damaged system image. To correct that open an elevated command prompt (you'll find it by right clicking the Start button) and then run the following command:

• DISM.exe/Online /Cleanup-image /Restorehealth

I suggest you copy/paste it as opposed to typing it to avoid errors.

[adrian]

Thanks for the suggestion Hitchhiker. Unfortunately, that had no effect. There was no corruption detected.

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================================= Checking System Update Readiness. Summary: Operation: Detect and Repair Operation result: 0x0 Last Successful Step: Entire operation completes. Total Detected Corruption: 0 CBS Manifest Corruption: 0 CBS Metadata Corruption: 0 CSI Manifest Corruption: 0 CSI Metadata Corruption: 0 CSI Payload Corruption: 0 Total Repaired Corruption: 0 CBS Manifest Repaired: 0 CSI Manifest Repaired: 0 CSI Payload Repaired: 0 CSI Store Metadata refreshed: True Total Operation Time: 441 seconds.

[Rémi Denis-Courmont]

Known issue. Stop the video instead of pausing.

[adrian]

Hi Remi,

So this won't be address anytime soon then I take it? Thanks for confirming.