Am 21.05.21 um 17:16 schrieb Daniel Vetter:
On Fri, May 21, 2021 at 05:00:46PM +0200, Bas Nieuwenhuizen wrote:
On Fri, May 21, 2021 at 4:37 PM Daniel Vetter <daniel@xxxxxxxx> wrote:
On Fri, May 21, 2021 at 11:46:23AM +0200, Bas Nieuwenhuizen wrote:
On Fri, May 21, 2021 at 11:10 AM Daniel Vetter <daniel.vetter@xxxxxxxx> wrote:
---
drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 88a24a0b5691..cc8426e1e8a8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -617,8 +617,8 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
amdgpu_bo_list_for_each_entry(e, p->bo_list) {
struct amdgpu_bo *bo = ttm_to_amdgpu_bo(e->tv.bo);
- /* Make sure we use the exclusive slot for shared BOs */
- if (bo->prime_shared_count)
+ /* Make sure we use the exclusive slot for all potentially shared BOs */
+ if (!(bo->flags & AMDGPU_GEM_CREATE_VM_ALWAYS_VALID))
e->tv.num_shared = 0;
I think it also makes sense to skip this with
AMDGPU_GEM_CREATE_EXPLICIT_SYNC? It can be shared but I don't think
anyone expects implicit sync to happen with those.
Ah yes, I missed this entirely. So the "no implicit flag" is already
there, and the _only_ thing that's missing really is a way to fish out the
implicit fences, and set them.
https://lore.kernel.org/dri-devel/20210520190007.534046-1-jason@xxxxxxxxxxxxxx/
So I think all that's really needed in radv is not setting
RADEON_FLAG_IMPLICIT_SYNC for winsys buffers when Jason's dma-buf ioctl
are present (means you need to do some import/export and keep the fd
around for winsys buffers, but shouldn't be too bad), and then control the
implicit fences entirely explicitly like vk expects.
That is the part I'm less sure about. This is a BO wide flag so we are
also disabling implicit sync in the compositor. If the compositor does
only do read stuff that is ok, as the inserted exclusive fence will
work for that. But as I learned recently the app provided buffer may
end up being written to by the X server which open a whole can of
potential problems if implicit sync gets disabled between Xserver
operations on the app provided buffer. Hence setting that on the WSI
buffer is a whole new can of potential problems and hence I've said a
submission based flag would be preferred.
I can certainly try it out though.
Hm yeah that's the wrong flag. We need a flag on the drm_file which the
explicit userspace sets. And which is valid only for itself.
There's a nice flags field when creating a ctx, but it's not validated and
there's already a comment that we have to filter out garbage priority, so
that's not use. I'll whip up something entirely untested just as a draft.
We could provide an IOCTL for the BO to change the flag.
But could we first figure out the semantics we want to use here?
Cause I'm pretty sure we don't actually need those changes at all and as
said before I'm certainly NAKing things which break existing use cases.
Regards,
Christian.
-Daniel
Are you bored enough to type this up for radv? I'll give Jason's kernel
stuff another review meanwhile.
-Daniel
e->bo_va = amdgpu_vm_bo_find(vm, bo);
}
--
2.31.0
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
