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xc-llm-ascend/docs/source/user_guide/configuration/additional_config.md
zzzzwwjj a40eee2ba1 [feat] support dispatch_v2/combine_v2 hierarchy communication (#7698)
### What this PR does / why we need it?

This PR adds support for hierarchical communication for `dispatch_v2`
and `combine_v2` MoE operations. This is achieved by introducing a new
configuration `enable_mc2_hierarchy_comm`. When enabled, the
communication algorithm is set to "hierarchy", which support mc2 op comm
between two super pod.

The changes include:
- Adding `enable_mc2_hierarchy_comm` to `AscendConfig`.
- Modifying `TokenDispatcherWithMC2` to pass `comm_alg: "hierarchy"` to
the underlying `torch_npu` ops when the new config is enabled.
- Adding validation to ensure that this feature is only used with
compatible PTA/CANN versions and is not used with the conflicting
`fused_mc2` op.
- Updating `is_hierarchical_communication_enabled` to respect the new
configuration flag.

### Does this PR introduce _any_ user-facing change?

Yes, this PR introduces a new user-facing configuration option
`enable_mc2_hierarchy_comm` in `additional_config` to enable
hierarchical communication for MoE.

### How was this patch tested?

- vLLM version: v0.18.0

Signed-off-by: zzzzwwjj <1183291235@qq.com>
2026-03-27 09:20:16 +08:00

130 lines
8.1 KiB
Markdown

# Additional Configuration
Additional configuration is a mechanism provided by vLLM to allow plugins to control internal behavior by themselves. VLLM Ascend uses this mechanism to make the project more flexible.
## How to use
With either online mode or offline mode, users can use additional configuration. Take Qwen3 as an example:
**Online mode**:
```bash
vllm serve Qwen/Qwen3-8B --additional-config='{"config_key":"config_value"}'
```
**Offline mode**:
```python
from vllm import LLM
LLM(model="Qwen/Qwen3-8B", additional_config={"config_key":"config_value"})
```
### Configuration options
The following table lists additional configuration options available in vLLM Ascend:
| Name | Type | Default | Description |
|-------------------------------------|------|---------|-----------------------------------------------------------------------------------------------------------|
| `xlite_graph_config` | dict | `{}` | Configuration options for Xlite graph mode |
| `weight_prefetch_config` | dict | `{}` | Configuration options for weight prefetch |
| `finegrained_tp_config` | dict | `{}` | Configuration options for module tensor parallelism |
| `ascend_compilation_config` | dict | `{}` | Configuration options for ascend compilation |
| `eplb_config` | dict | `{}` | Configuration options for ascend compilation |
| `refresh` | bool | `false` | Whether to refresh global Ascend configuration content. This is usually used by rlhf or ut/e2e test case. |
| `dump_config_path` | str | `None` | Configuration file path for msprobe dump(eager mode). |
| `enable_async_exponential` | bool | `False` | Whether to enable asynchronous exponential overlap. To enable asynchronous exponential, set this config to True. |
| `enable_shared_expert_dp` | bool | `False` | When the expert is shared in DP, it delivers better performance but consumes more memory. Currently only DeepSeek series models are supported. |
| `multistream_overlap_shared_expert` | bool | `False` | Whether to enable multi-stream shared expert. This option only takes effect on MoE models with shared experts. |
| `multistream_overlap_gate` | bool | `False` | Whether to enable multi-stream overlap gate. This option only takes effect on MoE models with shared experts. |
| `recompute_scheduler_enable` | bool | `False` | Whether to enable recompute scheduler. |
| `enable_cpu_binding` | bool | `True` | Whether to enable CPU binding. Only takes effect on ARM CPUs; A3 uses the global-slicing CPU allocation strategy and other device types use the topo-affinity CPU allocation strategy. |
| `SLO_limits_for_dynamic_batch` | int | `-1` | SLO limits for dynamic batch. This is new scheduler to support dynamic batch feature |
| `enable_npugraph_ex` | bool | `False` | Whether to enable npugraph_ex graph mode. |
| `pa_shape_list` | list | `[]` | The custom shape list of page attention ops. |
| `enable_kv_nz` | bool | `False` | Whether to enable KV cache NZ layout. This option only takes effects on models using MLA (e.g., DeepSeek). |
| `layer_sharding` | dict | `{}` | Configuration options for Layer Sharding Linear |
| `enable_sparse_c8` | bool | `False` | Whether to enable KV cache C8 in DSA models (e.g., DeepSeekV3.2 and GLM5). Not supported on A5 devices now |
| `enable_mc2_hierarchy_comm` | bool | `False` | Enable dispatch/combine op inter-node communication by ROCE. |
The details of each configuration option are as follows:
**xlite_graph_config**
| Name | Type | Default | Description |
| ---- | ---- | ------- | ----------- |
| `enabled` | bool | `False` | Whether to enable Xlite graph mode. Currently only Llama, Qwen dense series models, and Qwen3-VL are supported. |
| `full_mode` | bool | `False` | Whether to enable Xlite for both the prefill and decode stages. By default, Xlite is only enabled for the decode stage. |
**weight_prefetch_config**
| Name | Type | Default | Description |
|------------------|------|-------------------------------------------------------------|------------------------------------|
| `enabled` | bool | `False` | Whether to enable weight prefetch. |
| `prefetch_ratio` | dict | `{"attn": {"qkv": 1.0, "o": 1.0}, "moe": {"gate_up": 0.8}, "mlp": { "gate_up": 1.0, "down": 1.0}}` | Prefetch ratio of each weight. |
**finegrained_tp_config**
| Name | Type | Default | Description |
| ---- | ---- | ------- | ----------- |
| `lmhead_tensor_parallel_size` | int | `0` | The custom tensor parallel size of lm_head. |
| `oproj_tensor_parallel_size` | int | `0` | The custom tensor parallel size of o_proj. |
| `embedding_tensor_parallel_size` | int | `0` | The custom tensor parallel size of embedding. |
| `mlp_tensor_parallel_size` | int | `0` | The custom tensor parallel size of mlp. |
**ascend_compilation_config**
| Name | Type | Default | Description |
| ---- | ---- | ------- | ----------- |
| `enable_npugraph_ex` | bool | `True` | Whether to enable npugraph_ex backend. |
| `enable_static_kernel` | bool | `False` | Whether to enable static kernel. Suitable for scenarios where shape changes are minimal and some time is available for static kernel compilation. |
| `fuse_norm_quant` | bool | `True` | Whether to enable fuse_norm_quant pass. |
| `fuse_qknorm_rope` | bool | `True` | Whether to enable fuse_qknorm_rope pass. If Triton is not in the environment, set it to False. |
| `fuse_allreduce_rms` | bool | `False` | Whether to enable fuse_allreduce_rms pass. It's set to False because of conflict with SP. |
| `fuse_muls_add` | bool | `True` | Whether to enable fuse_muls_add pass.|
**eplb_config**
| Name | Type | Default | Description |
| ---- | ---- | ------- | ----------- |
| `dynamic_eplb` | bool| `False`| Whether to enable dynamic EPLB. |
| `expert_map_path` | str | `None` | When using expert load balancing for an MoE model, an expert map path needs to be passed in.|
| `expert_heat_collection_interval`| int | `400` | Forward iterations when EPLB begins. |
| `algorithm_execution_interval` | int | `30` | The forward iterations when the EPLB worker will finish CPU tasks. |
| `expert_map_record_path` | str | `None` | Save the expert load calculation results to a new expert table in the specified directory.|
| `num_redundant_experts` | int | `0` | Specify redundant experts during initialization. |
### Example
An example of additional configuration is as follows:
```python
{
"weight_prefetch_config": {
"enabled": True,
"prefetch_ratio": {
"attn": {
"qkv": 1.0,
"o": 1.0,
},
"moe": {
"gate_up": 0.8
},
"mlp": {
"gate_up": 1.0,
"down": 1.0
}
},
},
"finegrained_tp_config": {
"lmhead_tensor_parallel_size": 8,
"oproj_tensor_parallel_size": 8,
"embedding_tensor_parallel_size": 8,
"mlp_tensor_parallel_size": 8,
},
"enable_kv_nz": False,
"multistream_overlap_shared_expert": True,
"refresh": False
}
```