Hi Monk,
this patch doesn't prevents PD/PT eviction.
The intention of the code here was that per VM BOs can evict other per
VM BOs during allocation.
The problem my patch fixes is that this unfortunately also meant that
allocation PDs/PTs could evict other PDs/PTs from the same process.
Re
Hi Christian
Theoretically the vm pt/pd should be allowed to be evicted like other BOs ..
If you encountered page fault and could be avoided by this patch, that means
there is bug in the VM/ttm system , and your patch simply
w/a the root cause.
_
Monk Liu|GP
If the page tables are reserved or fenced while you allocate a new one, they
would not be evicted.
And exactly that's not correct. The TTM_OPT_FLAG_ALLOW_RES_EVICT flag
allows evicting of reserved objects.
This is useful for allocating per VM BOs, but is of course completely
fatal in all othe
I'm not disagreeing with the change. Just trying to understand how this
could have caused a VM fault. If the page tables are reserved or fenced
while you allocate a new one, they would not be evicted. If they are not
reserved or fenced, there should be no expectation that they stay resident.
Is
Acked-by: Alex Deucher
From: amd-gfx on behalf of Christian
König
Sent: Thursday, September 19, 2019 4:41 AM
To: amd-gfx@lists.freedesktop.org
Subject: [PATCH] drm/amdgpu: fix potential VM faults
When we allocate new page tables under memory
pressure we should
