Superminaren/llama.cpp
1
0
Fork 0
mirror of https://github.com/ggml-org/llama.cpp.git synced 2026-09-11 04:56:56 +02:00
Code Issues Packages Projects Releases Wiki Activity

vulkan: use CPU writes in ggml_backend_vk_cpy_tensor_async if the context is idle (#28618)

Browse Source
This commit is contained in:
Jeff Bolz
2026-09-10 20:22:46 +03:00
committed by GitHub
parent 50182a53fa
commit 28ff095829
1 changed files with 16 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
ggml/src/ggml-vulkan/ggml-vulkan.cpp
+16 -1
View File
@@ -17135,6 +17135,22 @@ static bool ggml_backend_vk_cpy_tensor_async(ggml_backend_t backend_src, ggml_ba
return false;
}
// If the backend is idle, use a CPU copy to avoid GPU synchronization overhead.
static constexpr size_t max_cpu_copy_size = 128 * 1024;
const bool src_backend_synchronous = backend_src->iface.synchronize == nullptr;
const bool transfer_idle = !ctx->device->async_use_transfer_queue ||
ctx->transfer_semaphore_last_submitted == ctx->transfer_semaphore.value;
const bool backend_idle = ctx->compute_ctx.expired() && ctx->transfer_ctx.expired() &&
!ctx->submit_pending && !ctx->almost_ready_fence_pending && transfer_idle;
const bool dst_host_coherent =
(dst_buf->memory_property_flags & (vk::MemoryPropertyFlagBits::eHostVisible | vk::MemoryPropertyFlagBits::eHostCoherent)) ==
(vk::MemoryPropertyFlagBits::eHostVisible | vk::MemoryPropertyFlagBits::eHostCoherent);
if ((backend_src == backend_dst || src_backend_synchronous) && backend_idle && dst_host_coherent && ggml_nbytes(src) <= max_cpu_copy_size) {
ggml_vk_buffer_write(dst_buf, vk_tensor_offset(dst) + dst->view_offs, src->data, ggml_nbytes(src));
return true;
}
vk_context cpy_ctx;
if (ctx->device->async_use_transfer_queue) {
cpy_ctx = ggml_vk_get_transfer_ctx(ctx);
@@ -17147,7 +17163,6 @@ static bool ggml_backend_vk_cpy_tensor_async(ggml_backend_t backend_src, ggml_ba
src->data, ggml_nbytes(src));
}
GGML_UNUSED(backend_src);
return false;
}