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imx53 video DMA memory fragmentation

Question asked by Tim Woodham on Nov 16, 2015
Latest reply on Nov 19, 2015 by Yuri Muhin

We use the analogue video input to display video on our screen on the imx53 standard platform which has a problem with displaying the video feed for an extended amount of time.  On average we're finding that after about 3 weeks of displaying the video feed on the screen we get DMA memory fragmentation.  The DMA memory fragmentation fragments so much that the video cannot start as it cannot allocate a contiguous memory block big enough and the video cannot be displayed.

 

The Linux kernel is 2.6.35.3 11_09 and we use the command to run the video

/unit_tests/mxc_v4l2_tvin.out -ow 450 -oh 600 -ol 550 -ot 1 -r 6 -f YU12

 

I've found the cat /proc/buddyinfo indicates that over time the free slots are 0's down to the size required to start the video

 

I've found that the memory compaction isn't available with this kernel release which is meant to re-order slots to fix the memory fragmentation issue that we're seeing.

 

The question is,

Has anyone found issues with displaying video for extended amounts of time on the imx53 linux 2.6.35.3 11_09 image. 

 

Has anyone found the need to get the compact the memory fragmentation which doesn't seem available as it doesn't compile in the 2.6.35 kernel.

 

Thanks in advance,

Tim

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