[Mesa-dev] [PATCH v3 2/3] i965: add noise padding to buffer object and function to check if noise is correct

[Chris Wilson]

Quoting Jason Ekstrand (2018-01-26 18:01:05)
> I wasn't suggesting that you use pread *instead* of stalling.  But once you've
> stalled, nothing will be touching it.  There is the possibility of another
> context or process of it's shared but mapping won't protect you from that
> either.  I don't know what Chris was getting at.

Iirc, I was talking about pread would only wait for previous
EXEC_OBJECT_WRITE requests, it would not wait for any undeclared stray
write into the bo. To be sure you catch the GPU writing into a set of
read-only buffers, you have to stall for all GPU activity.
-Chris