enable peer access (NVlink) (#1050)

* enable peer access for cuda

* Remove redundant loop
This commit is contained in:
abc-nix
2025-12-11 07:31:56 +00:00
committed by GitHub
parent 279b4c44fc
commit 37e41d22dc

View File

@@ -1434,59 +1434,30 @@ static void ggml_cuda_op_mul_mat_cublas(
GGML_UNUSED(src1_padded_row_size);
}
#if 0
static void ggml_cuda_set_peer_access(const int n_tokens, int main_device) {
static bool peer_access_enabled = false;
static void ggml_cuda_set_peer_access(int main_device) {
ggml_cuda_set_device(main_device);
const bool enable_peer_access = n_tokens <= GGML_CUDA_PEER_MAX_BATCH_SIZE;
for (int id_other = 0; id_other < ggml_backend_cuda_get_device_count(); ++id_other) {
if (main_device == id_other) {
continue;
}
if (peer_access_enabled == enable_peer_access) {
return;
}
#ifdef NDEBUG
for (int id = 0; id < ggml_backend_cuda_get_device_count(); ++id) {
ggml_cuda_set_device(id);
CUDA_CHECK(cudaDeviceSynchronize());
}
for (int id = 0; id < ggml_backend_cuda_get_device_count(); ++id) {
ggml_cuda_set_device(id);
for (int id_other = 0; id_other < ggml_backend_cuda_get_device_count(); ++id_other) {
if (id == id_other) {
continue;
}
if (id != main_device && id_other != main_device) {
continue;
}
int can_access_peer;
CUDA_CHECK(cudaDeviceCanAccessPeer(&can_access_peer, id, id_other));
if (can_access_peer) {
if (enable_peer_access) {
cudaError_t err = cudaDeviceEnablePeerAccess(id_other, 0);
if (err != cudaErrorPeerAccessAlreadyEnabled) {
CUDA_CHECK(err);
}
} else {
cudaError_t err = cudaDeviceDisablePeerAccess(id_other);
if (err != cudaErrorPeerAccessNotEnabled) {
CUDA_CHECK(err);
}
}
int can_access_peer;
CUDA_CHECK(cudaDeviceCanAccessPeer(&can_access_peer, main_device, id_other));
if (can_access_peer) {
//~ #ifdef NDEBUG
GGML_CUDA_LOG_INFO(" =========================== %s: Enabling Peer Access between Devices %d->%d\n", __func__, main_device, id_other);
//~ #endif //NDEBUG
cudaError_t err = cudaDeviceEnablePeerAccess(id_other, 0);
if (err != cudaErrorPeerAccessAlreadyEnabled) {
CUDA_CHECK(err);
} else {
// reset the error
(void)cudaGetLastError();
}
}
}
ggml_cuda_set_device(main_device);
#endif // NDEBUG
peer_access_enabled = enable_peer_access;
GGML_UNUSED(main_device);
}
#endif
static cudaError_t ggml_cuda_Memcpy2DPeerAsync(
void * dst, int dstDevice, size_t dpitch, void * src, int srcDevice, size_t spitch, size_t width, size_t height, cudaStream_t stream) {
@@ -4390,6 +4361,10 @@ GGML_CALL ggml_backend_t ggml_backend_cuda_init(int device, [[maybe_unused]] con
#endif
}
#if !defined(GGML_CUDA_NO_PEER_COPY)
ggml_cuda_set_peer_access(device);
#endif
return cuda_backend;
}