Re: tinydrm: page allocation failure

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 12/11/2017 06:45 AM, Noralf Trønnes wrote:

Den 11.12.2017 04.28, skrev David Lechner:
I'm using drm-misc/drm-misc-next and occasionally getting errors as seen in the stack traces below. I'm not really sure what to make of it. Any ideas?


I'm starting to wonder if there is some sort of race condition involved. I only get this warning on some boots, but when I do, it happens multiple times. Also, when I was debugging a an unrelated problem, I enabled some of the spin lock checking kernel options that really slow down the kernel. When I did this, I got this warning all of the time.

Would it be sensible to allocate a dummy RX buffer once instead of letting SPI allocate a new one for every transfer?


The spi controller driver has told the spi core to allocate dummy
buffers for tx/rx: spi_sync -> __spi_pump_messages -> spi_map_msg
-> krealloc -> __do_krealloc -> kmalloc_track_caller

order:4 means it's trying to allocate 2^4*PAGE_SIZE = 64kB, which
probably is the max DMA limit. So this is a pixel data transfer.

On my Raspberry Pi I've got 43 chunks of 64kB available if I have
understood this right:

$ sudo cat /proc/buddyinfo
Node 0, zone   Normal     40     68     66     51     43     46 13 1      3      3     75

I don't know what those dummy buffers are used for.

Noralf.

_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel




[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux