Am 26.03.2018 um 03:31 schrieb Felix Kühling: > Am 2018-03-24 um 04:34 AM schrieb Christian König: >> Am 23.03.2018 um 20:53 schrieb Felix Kuehling: >>> On 2018-03-23 03:35 PM, Christian König wrote: >>>> Am 23.03.2018 um 20:30 schrieb Felix Kuehling: >>>>> On large-BAR systems the VM page tables for compute are accessed by >>>>> the CPU. Always allow CPU access to the page directory so that it can >>>>> be used later by the CPU when a VM is converted to a compute VM. >>>> NAK, that means we initial place the PD in the visible are for GFX >>>> which is not desired (not much of an issue for Vega/Raven, but bad for >>>> older generations). >>> I'm not setting AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED. Doesn't that mean >>> the buffer can be placed in invisible VRAM initially? >> The difference is the preference. When AMDGPU_GEM_CREATE_NO_CPU_ACCESS >> is set we try to place it initially in invisible VRAM. > Where is that done? I'm looking at amdgpu_ttm_placement_from_domain. It > only looks at AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED. Of course! I have to apologize, my memory fooled me and I mixed up the handling of two flags. Didn't had the chance on the weekend to actually double check the code, but you're absolutely right. > [SNIP] >> If you want to avoid the move of the page directory on large BAR >> systems when switching a VM from GFX to compute we can also initially >> create the BO in the system domain. >> >> Thinking about that a bit more that is probably a good idea anyway >> because it avoids using VRAM by just opening the device. > Sure, I'd do that as a separate change because it actually changes the > initial placement, whereas my patch did not (as far as I can tell). Yeah, indeed. Creating the BO in the system domain would also simplify the eviction double check dance. Anyway this patch is Reviewed-by: Christian König <christian.koenig at amd.com> and sorry for the noise. Regards, Christian. > > Regards, >  Felix > >> Regards, >> Christian. >> >>> Regards, >>>   Felix >>> >>>> Regards, >>>> Christian. >>>> >>>>> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com> >>>>> --- >>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 3 +-- >>>>>   1 file changed, 1 insertion(+), 2 deletions(-) >>>>> >>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c >>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c >>>>> index 90ff79e..bc3557b 100644 >>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c >>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c >>>>> @@ -2406,8 +2406,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, >>>>> struct amdgpu_vm *vm, >>>>>       if (vm->use_cpu_for_update) >>>>>           flags |= AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED; >>>>>       else >>>>> -       flags |= (AMDGPU_GEM_CREATE_NO_CPU_ACCESS | >>>>> -               AMDGPU_GEM_CREATE_SHADOW); >>>>> +       flags |= AMDGPU_GEM_CREATE_SHADOW; >>>>>        size = amdgpu_vm_bo_size(adev, adev->vm_manager.root_level); >>>>>       r = amdgpu_bo_create(adev, size, align, true, >>>>> AMDGPU_GEM_DOMAIN_VRAM, >>> _______________________________________________ >>> amd-gfx mailing list >>> amd-gfx at lists.freedesktop.org >>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx >> _______________________________________________ >> amd-gfx mailing list >> amd-gfx at lists.freedesktop.org >> https://lists.freedesktop.org/mailman/listinfo/amd-gfx > >
