use mmap to reduce unbounded memory usage for split-tensor graph parallell loading (#2102)

This commit is contained in:
Farmadupe
2026-07-09 19:27:18 +03:00
committed by GitHub
parent 3bb0e9f09c
commit c32c3819f7
+14 -8
View File
@@ -1078,6 +1078,8 @@ bool llama_model_loader::load_all_data(
std::vector<void*> host_ptrs;
std::vector<ggml_backend_event_t> events;
std::vector<std::unique_ptr<llama_mmap>> split_mappings(files.size());
ggml_backend_t cuda_backend = nullptr;
if (!use_mmap && !check_tensors) {
// When not using mmaped io use async uploads from pinned memory to GPU memory.
@@ -1197,17 +1199,21 @@ bool llama_model_loader::load_all_data(
const char * buffer_name = ggml_backend_buffer_name(cur->buffer);
const bool is_probably_split_mode_graph = std::strncmp(buffer_name, GGML_CUDA_NAME, strlen(GGML_CUDA_NAME)) == 0;
if (is_probably_split_mode_graph) {
auto & read_buf = read_bufs[thread_idx];
if (read_buf.capacity() > n_size) {
read_buf = std::vector<no_init<uint8_t>>();
llama_mmap * mapping;
{
std::lock_guard<std::mutex> lock(load_mutex);
auto & m = split_mappings[weight->idx];
if (!m) {
m.reset(new llama_mmap(files.at(weight->idx).get(), 0, ggml_is_numa()));
}
mapping = m.get();
}
read_buf.resize(n_size);
file->seek(weight->offs, SEEK_SET);
file->read_raw(read_buf.data(), n_size);
ggml_backend_tensor_set(cur, read_buf.data(), 0, n_size);
if (check_tensors && !ggml_validate_row_data(cur->type, read_buf.data(), n_size)) {
uint8_t * data = (uint8_t *) mapping->addr() + weight->offs;
ggml_backend_tensor_set(cur, data, 0, n_size);
if (check_tensors && !ggml_validate_row_data(cur->type, data, n_size)) {
throw std::runtime_error(format("tensor '%s' has invalid data", ggml_get_name(cur)));
}
mapping->dontneed_fragment(weight->offs, weight->offs + n_size);
return n_size;
}
#endif