Optimize Vulkan backend for better CPU performance and less GPU synchronization overhead. (#8943)
* Optimize Vulkan backend for better CPU performance and less GPU synchronization overhead.
- Allocation overhead for the temporary std::vectors was easily detectable with a sampling profiler and simple to remove.
- ggml_vk_sync_buffer introduce a full pipeline sync which has a significant cost on the GPU side, sometimes larger than the actual kernel execution. Adding only barriers for shader read/writes and transfers seems to be sufficient looking at the code which either launches compute kernels or copies tensors.
overview / pkg / ggml / sources / llama.cpp / commit