Hi, Lang,
On 5/31/21 10:19 AM, Yu, Lang wrote:
[Public]
Hi,
On 5/27/21 3:30 AM, Lang Yu wrote:
Make TTM_PL_FLAG_* start from zero and add
TTM_PL_FLAG_TEMPORARY flag for temporary
GTT allocation use.
GTT is a driver private acronym, right? And it doesn't look like
TTM_PL_FLAG_TEMPORARY will be used in core TTM, so should we instead set
aside a mask in the PL flag for driver-private use?
Hi Thomas,
Thanks for your comments and advice, GTT means Graphics Translation Table here, seems
a general acronym. TTM_PL_FLAG_TEMPORARY may also be used by other drives.
I have made other patches for this. Please help review.
Regards,
Lang
My point was really that the flag naming and documentation should
reflect what core ttm is doing with that flag. If there is no specific
core TTM usage, IMO we should move it to a driver specific flag to avoid
future confusion. In particular a writer of a generic TTM resource
manager should be able to know without looking at an old commit message
what the placement flag is intended for.
So here we add a flag where core TTM forces a bo move on validate and
that's it. And that appears to be how it's used when an amdgpu bo is
evicted to GTT, (btw should it be accounted in this situation?)
The other use is to force the amdgpu driver to temporarily accept it
into GTT when there is a lack of space, and IMHO that's a driver
specific use and we should allocate a mask for driver specific flags for
that.
So shouldn't this be two flags, really?
TTM_PL_FLAG_FORCE_MOVE
and
AMDGPU_PL_FLAG_TEMPORARY
Thanks,
/Thomas
Thomas
-----Original Message-----
From: Yu, Lang <Lang.Yu@xxxxxxx>
Sent: Thursday, May 27, 2021 9:31 AM
To: amd-gfx@xxxxxxxxxxxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: Koenig, Christian <Christian.Koenig@xxxxxxx>; Huang, Ray
<Ray.Huang@xxxxxxx>; Deucher, Alexander <Alexander.Deucher@xxxxxxx>;
Yu, Lang <Lang.Yu@xxxxxxx>
Subject: [PATCH 1/2] drm/ttm: cleanup and add TTM_PL_FLAG_TEMPORARY
Make TTM_PL_FLAG_* start from zero and add TTM_PL_FLAG_TEMPORARY flag
for temporary GTT allocation use.
Signed-off-by: Lang Yu <Lang.Yu@xxxxxxx>
---
include/drm/ttm/ttm_placement.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/drm/ttm/ttm_placement.h
b/include/drm/ttm/ttm_placement.h index aa6ba4d0cf78..9f5cfc7c2d5a 100644
--- a/include/drm/ttm/ttm_placement.h
+++ b/include/drm/ttm/ttm_placement.h
@@ -47,8 +47,9 @@
* top of the memory area, instead of the bottom.
*/
-#define TTM_PL_FLAG_CONTIGUOUS (1 << 19)
-#define TTM_PL_FLAG_TOPDOWN (1 << 22)
+#define TTM_PL_FLAG_CONTIGUOUS (1 << 0)
+#define TTM_PL_FLAG_TOPDOWN (1 << 1)
+#define TTM_PL_FLAG_TEMPORARY (1 << 2)
/**
* struct ttm_place
--
2.25.1
