[Linaro-mm-sig] [PATCH] dma-fence: Document recoverable page fault implications

[Thomas Hellström (Intel)]

On 2/3/21 4:29 PM, Daniel Vetter wrote:
> Recently there was a fairly long thread about recoreable hardware page
> faults, how they can deadlock, and what to do about that.
>
> While the discussion is still fresh I figured good time to try and
> document the conclusions a bit. This documentation section explains
> what's the potential problem, and the remedies we've discussed,
> roughly ordered from best to worst.
>
> v2: Linus -> Linux typoe (Dave)
>
> v3:
> - Make it clear drivers only need to implement one option (Christian)
> - Make it clearer that implicit sync is out the window with exclusive
>    fences (Christian)
> - Add the fairly theoretical option of segementing the memory (either
>    statically or through dynamic checks at runtime for which piece of
>    memory is managed how) and explain why it's not a great idea (Felix)
>
> References: https://lore.kernel.org/dri-devel/20210107030127.20393-1-Felix.Kuehling@amd.com/
> Cc: Dave Airlie <airlied at gmail.com>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Thomas Hellström <thomas.hellstrom at intel.com>
> Cc: "Christian König" <christian.koenig at amd.com>
> Cc: Jerome Glisse <jglisse at redhat.com>
> Cc: Felix Kuehling <felix.kuehling at amd.com>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Sumit Semwal <sumit.semwal at linaro.org>
> Cc: linux-media at vger.kernel.org
> Cc: linaro-mm-sig at lists.linaro.org
> ---
>   Documentation/driver-api/dma-buf.rst | 76 ++++++++++++++++++++++++++++
>   1 file changed, 76 insertions(+)
>
Acked-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>