Merge pull request #237 from nvpbrown/nv-publish-2019-01-14
Publish minor NVIDIA extension spec edits.
diff --git a/extensions/NV/NV_gpu_multicast.txt b/extensions/NV/NV_gpu_multicast.txt
index 74e086f..1fc2e7e 100644
--- a/extensions/NV/NV_gpu_multicast.txt
+++ b/extensions/NV/NV_gpu_multicast.txt
@@ -25,8 +25,8 @@
Version
- Last Modified Date: October 7, 2016
- Revision: 5
+ Last Modified Date: January 3, 2019
+ Revision: 6
Number
@@ -157,13 +157,13 @@
instance of a resource, it is considered to have per-GPU storage. When all GPUs share a
single instance of a resource, this is considered GPU-shared storage.
- The mechanism for linking GPUs is implementation specific, as is the process-global mechanism
- for enabling multicast rendering support (if necessary). The number of GPUs usable for
- multicast rendering by a context can be queried by calling GetIntegerv with the symbolic
- constant MULTICAST_GPUS_NV. Individual GPUs are identified using zero-based indices in the
- range [0, n-1], where n is the number of multicast GPUs. GPUs are also be identified by
- bitmasks of the form 2^i, where i is the GPU index. A set of GPUs is specified by the union
- of masks for each GPU in the set.
+ The mechanism for linking GPUs is implementation specific, as is the mechanism for enabling
+ multicast rendering support (if necessary). The number of GPUs usable for multicast rendering
+ by a context can be queried by calling GetIntegerv with the symbolic constant
+ MULTICAST_GPUS_NV. This number is constant for the lifetime of a context. Individual GPUs
+ are identified using zero-based indices in the range [0, n-1], where n is the number of
+ multicast GPUs. GPUs are also identified by bitmasks of the form 2^i, where i is the GPU
+ index. A set of GPUs is specified by the union of masks for each GPU in the set.
20.1 Controlling Individual GPUs
@@ -616,7 +616,7 @@
Minimum
Get Value Type Get Command Value Description Sec. Attribute
---------------------------- ------ ------------- ----- ---------------------- ---- ---------
- MULTICAST_GPUS_NV Z+ GetIntegerv 2 Number of linked GPUs 20.0 -
+ MULTICAST_GPUS_NV Z+ GetIntegerv 1 Number of linked GPUs 20.0 -
usable for multicast
Backwards Compatibility
@@ -705,10 +705,10 @@
(4) What happens if the MulticastCopyBufferSubDataNV source and destination buffer is the same?
- RESOLVED. When the source and destination make involve the same GPU,
- MulticastCopyBufferSubDataNV matches the behavior of CopyBufferSubData: overlapped copies are
- not allowed and an INVALID_VALUE error results. When the source and destination do not
- involve the same GPU, overlapping copies are allowed and no error is generated.
+ RESOLVED. When the source and destination involve the same GPU, MulticastCopyBufferSubDataNV
+ matches the behavior of CopyBufferSubData: overlapped copies are not allowed and an
+ INVALID_VALUE error results. When the source and destination do not involve the same GPU,
+ overlapping copies are allowed and no error is generated.
(5) How does this extension interact with CopyTexImage2D?
@@ -731,9 +731,11 @@
(8) Should we expose the extension on single-GPU configurations?
- RESOLVED. No. The extension provides no value unless MULTICAST_GPUS_NV > 1. Limiting exposure
- to these configurations guarantees that at least two GPUs will be available when the extension
- is reported.
+ RESOLVED. Yes, this is recommended. It allows more code sharing between multi-GPU and
+ single-GPU code paths. If there is only one GPU present MULTICAST_GPUS_NV will be 1. It
+ may also be 1 if explicit GPU control is unavailable (e.g. if the active multi-GPU rendering
+ mode prevents it). Note that in revisions 5 and prior of this extension the minimum for
+ MULTICAST_GPUS_NV was 2.
(9) Should glGet*BufferParameter* return the PER_GPU_STORAGE_BIT_NV bit when
BUFFER_STORAGE_FLAGS is queried?
@@ -774,6 +776,8 @@
Rev. Date Author Changes
---- -------- -------- -----------------------------------------------
+ 6 01/03/19 jschnarr reduce MULTICAST_GPUS_NV minimum to 1
+ clarify that MULTICAST_GPUS_NV is constant for a context
5 10/07/16 jschnarr trivial typo fix
4 07/21/16 mjk registered
3 06/15/16 jschnarr R370 release
diff --git a/extensions/NV/NV_mesh_shader.txt b/extensions/NV/NV_mesh_shader.txt
index f415821..bd0c56c 100644
--- a/extensions/NV/NV_mesh_shader.txt
+++ b/extensions/NV/NV_mesh_shader.txt
@@ -22,8 +22,8 @@
Version
- Last Modified Date: September 17, 2018
- NVIDIA Revision: 2
+ Last Modified Date: January 14, 2019
+ NVIDIA Revision: 3
Number
@@ -247,7 +247,7 @@
A single program object cannot mix mesh and task shader stages
with vertex, tessellation or geometry shader stages. Furthermore
a task shader stage cannot be combined with a fragment shader stage
- when the task shader stage is omitted. Other combinations as well
+ when the mesh shader stage is omitted. Other combinations as well
as their subsets are possible.
Modify Section 7.1, Shader Objects, p. 85
@@ -1075,6 +1075,10 @@
Revision History
+ Revision 3, January 14, 2019 (pbrown)
+ - Fix a typo in language prohibiting use of a task shader without a mesh
+ shader.
+
Revision 2, September 17, 2018 (pbrown)
- Prepare specification for publication.
