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.

Regards,
Christian.

Am 25.09.19 um 15:51 schrieb Liu, Monk:
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|GPU Virtualization Team |AMD


-----Original Message-----
From: amd-gfx <amd-gfx-boun...@lists.freedesktop.org> On Behalf Of Christian 
K?nig
Sent: Thursday, September 19, 2019 4:42 PM
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 not evict old 
ones.

Signed-off-by: Christian König <christian.koe...@amd.com>
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 3 ++-
  1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 70d45d48907a..8e44ecaada35 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -514,7 +514,8 @@ static int amdgpu_bo_do_create(struct amdgpu_device *adev,
                .interruptible = (bp->type != ttm_bo_type_kernel),
                .no_wait_gpu = bp->no_wait_gpu,
                .resv = bp->resv,
-               .flags = TTM_OPT_FLAG_ALLOW_RES_EVICT
+               .flags = bp->type != ttm_bo_type_kernel ?
+                       TTM_OPT_FLAG_ALLOW_RES_EVICT : 0
        };
        struct amdgpu_bo *bo;
        unsigned long page_align, size = bp->size;
--
2.17.1

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