Module: wine Branch: master Commit: c6b9aa7a7c44a97fccc5b5270e90786dfac1eb83 URL: https://gitlab.winehq.org/wine/wine/-/commit/c6b9aa7a7c44a97fccc5b5270e90786...
Author: Zebediah Figura zfigura@codeweavers.com Date: Tue Jul 18 00:31:02 2023 -0500
wined3d: Implement a copy-on-write scheme for whole buffer uploads.
For discard maps on deferred contexts, we currently blit from the upload buffer to the resource. This is necessary because command lists can be reused and submitted multiple times—we cannot simply have the buffer take ownership, as for discard maps on immediate contexts.
However, it is very common for applications to use command lists only once before throwing them away—in essence taking advantage of the feature only for the multithreading advantages it allows.
Therefore we take advantage of this pattern by trying to rename the buffer anyway. In order to do this we introduce a refcount for BO pointers. When writing to a buffer BO, we first check whether the buffer "owns" the BO—i.e. whether it has a refcount of 1—and if not, we create a new BO for the buffer and copy the contents of the old BO to the new BO. That is, we perform mostly-transparent copy-on-write.
This improves performance, and reduces CPU usage, in Assassin's Creed: Unity.
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dlls/wined3d/buffer.c | 87 +++++++++++++++++++++++++++++++++++++----- dlls/wined3d/context_gl.c | 3 ++ dlls/wined3d/context_vk.c | 5 +++ dlls/wined3d/cs.c | 7 +++- dlls/wined3d/device.c | 1 + dlls/wined3d/view.c | 10 +++++ dlls/wined3d/wined3d_private.h | 7 ++++ 7 files changed, 109 insertions(+), 11 deletions(-)