Re: DMA-API: cacheline tracking ENOMEM, dma-debug disabled due to nouveau ?

From: Daniel Vetter
Date: Wed Aug 14 2019 - 13:49:33 EST


On Wed, Aug 14, 2019 at 04:50:33PM +0200, Corentin Labbe wrote:
> Hello
>
> Since lot of release (at least since 4.19), I hit the following error message:
> DMA-API: cacheline tracking ENOMEM, dma-debug disabled
>
> After hitting that, I try to check who is creating so many DMA mapping and see:
> cat /sys/kernel/debug/dma-api/dump | cut -d' ' -f2 | sort | uniq -c
> 6 ahci
> 257 e1000e
> 6 ehci-pci
> 5891 nouveau
> 24 uhci_hcd
>
> Does nouveau having this high number of DMA mapping is normal ?

Yeah seems perfectly fine for a gpu.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch