llama: automatically set parameters not set by the user in such a way that maximizes GPU utilization (#16653)

* llama: automatically fit args to free memory

llama-fit-params tool

* fix CI

* hints for bug reports, ensure no reallocation

* fix segfault with Vulkan

* add llama-fit-params to CI

* fix CI

* fix CI

* fix CI

* minor adjustments

* fix assignment of 1 dense layer

* fix logger not being reset on model load failure

* remove --n-gpu-layer hint on model load failure

* fix llama-fit-params verbosity

* fix edge case

* fix typo [no ci]
This commit is contained in:
Johannes Gäßler
2025-12-15 09:24:59 +01:00
committed by GitHub
parent 4aced7a631
commit b1f3a6e5db
26 changed files with 1075 additions and 63 deletions
+20 -3
View File
@@ -175,7 +175,15 @@ llama_kv_cache::llama_kv_cache(
// allocate tensors and initialize the buffers to avoid NaNs in the padding
for (auto & [buft, ctx] : ctx_map) {
ggml_backend_buffer_t buf = ggml_backend_alloc_ctx_tensors_from_buft(ctx.get(), buft);
ggml_backend_buffer_t buf;
if (model.hparams.no_alloc) {
buf = ggml_backend_buft_alloc_buffer(buft, /*size =*/ 0); // dummy buffer
for (ggml_tensor * t = ggml_get_first_tensor(ctx.get()); t != nullptr; t = ggml_get_next_tensor(ctx.get(), t)) {
t->buffer = buf; // set dummy buffer for KV cache so that the backend scheduler won't try to allocate it
}
} else {
buf = ggml_backend_alloc_ctx_tensors_from_buft(ctx.get(), buft); // real buffer
}
if (!buf) {
throw std::runtime_error("failed to allocate buffer for kv cache");
}
@@ -482,9 +490,18 @@ llama_pos llama_kv_cache::seq_pos_max(llama_seq_id seq_id) const {
std::map<ggml_backend_buffer_type_t, size_t> llama_kv_cache::memory_breakdown() const {
std::map<ggml_backend_buffer_type_t, size_t> ret;
for (const auto & [_, buf] : ctxs_bufs) {
ret[ggml_backend_buffer_get_type(buf.get())] += ggml_backend_buffer_get_size(buf.get());
for (const auto & [ctx, buf] : ctxs_bufs) {
ggml_backend_buffer_type_t buft = ggml_backend_buffer_get_type(buf.get());
if (hparams.no_alloc) {
GGML_ASSERT(ggml_backend_buffer_get_base(buf.get()) == nullptr);
ret[buft] += ggml_backend_alloc_ctx_tensors_from_buft_size(ctx.get(), buft);
} else {
// GGML_ASSERT(ggml_backend_buffer_get_base(buf.get()) != nullptr); // multi_buffer does not have a defined base
ret[buft] += ggml_backend_buffer_get_size(buf.get());
}
}
return ret;
}