https://bugs.freedesktop.org/show_bug.cgi?id=107670
--- Comment #17 from [email protected] ---
(In reply to Michel Dänzer from comment #16)
> (In reply to iive from comment #15)
> > Aka, I do expect that the whole 512MB buffer is mapped at once.
>
> It's not (if it was, one process could access the buffer object memory of
> another process, bypassing process separation), TTM maps the memory of each
> buffer object into userspace individually.
>
> The whole MTRR thing is irrelevant anyway due to PAT.
>
> You've found the problem in glibc's memcpy() reading from the destination,
> no need to look any further.
The physical and effective addresses could be mapped 1:1, while each process
loads only the pages that belong to it. Meaning that pages owned by other
processes would simply remain unloaded in the current one.
Anyway,
This does not answer my question of how to (dis)prove that the memcpy does or
does not do vmem->vmem.
It is relevant, as one way to fix this issue is to NOT use memcpy() for
transfer, if DMA is already employed.
Axel Davy promised to take a look at that one, as it is related to Nine.
--
You are receiving this mail because:
You are the assignee for the bug.
You are the QA Contact for the bug.
_______________________________________________
mesa-dev mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/mesa-dev
