Merge branch 'main' into gating_topk_softmax

Author: ttanzhiqiang

.github/workflows/vllm_ascend_test.yaml

@@ -103,10 +103,6 @@ jobs:
           pip install yapf==0.32.0
           yapf --diff --recursive .
 
-      - name: Install dependencies
-        run: |
-          pip install -r requirements-dev.txt --extra-index-url https://download.pytorch.org/whl/cpu
-
       - name: Checkout vllm-project/vllm repo
         uses: actions/checkout@v4
         with:
@@ -126,6 +122,10 @@ jobs:
           pip install -r requirements/build.txt --extra-index-url https://download.pytorch.org/whl/cpu
           VLLM_TARGET_DEVICE=empty pip install .
 
+      - name: Install dependencies
+        run: |
+          pip install -r requirements-dev.txt --extra-index-url https://download.pytorch.org/whl/cpu
+
       - name: Mypy Check
         run: |
           echo "::add-matcher::.github/workflows/matchers/mypy.json"

examples/eplb/eplb_deepseek.py

@@ -0,0 +1,205 @@
+# SPDX-License-Identifier: Apache-2.0
+"""
+Expert parallelism load balancer (EPLB) for vLLM.
+The rearrangement algorithm is adapted from
+[DeepSeek EPLB](https://github.com/deepseek-ai/eplb).
+"""
+from typing import Tuple
+
+import torch
+
+
+def balanced_packing(weight: torch.Tensor,
+                     num_packs: int) -> Tuple[torch.Tensor, torch.Tensor]:
+    """
+    Pack n weighted objects to m packs, such that each bin contains exactly n/m objects and the weights of all packs
+    are as balanced as possible.
+
+    Parameters:
+        weight: [X, n], the weight of each item
+        num_packs: number of packs
+    
+    Returns: 
+        pack_index: [X, n], the pack index of each item
+        rank_in_pack: [X, n], the rank of the item in the pack
+    """
+    num_layers, num_groups = weight.shape
+    assert num_groups % num_packs == 0
+    groups_per_pack = num_groups // num_packs
+
+    if groups_per_pack == 1:
+        pack_index = torch.arange(weight.size(-1),
+                                  dtype=torch.int64,
+                                  device=weight.device).expand(weight.shape)
+        rank_in_pack = torch.zeros_like(weight, dtype=torch.int64)
+        return pack_index, rank_in_pack
+
+    indices = weight.float().sort(-1, descending=True).indices.cpu()
+    pack_index = torch.full_like(weight,
+                                 fill_value=-1,
+                                 dtype=torch.int64,
+                                 device='cpu')
+    rank_in_pack = torch.full_like(pack_index, fill_value=-1)
+    for i in range(num_layers):
+        pack_weights = [0] * num_packs
+        pack_items = [0] * num_packs
+        for group in indices[i]:
+            pack = min(
+                (i
+                 for i in range(num_packs) if pack_items[i] < groups_per_pack),
+                key=pack_weights.__getitem__)
+            assert pack_items[pack] < groups_per_pack
+            pack_index[i, group] = pack
+            rank_in_pack[i, group] = pack_items[pack]
+            pack_weights[pack] += weight[i, group]
+            pack_items[pack] += 1
+    return pack_index, rank_in_pack
+
+
+def replicate_experts(
+        weight: torch.Tensor,
+        num_phy: int) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor]:
+    """
+    Replicate `num_log` experts to `num_phy` replicas, such that the maximum load of all replicas is minimized.
+
+    Parameters:
+        weight: [X, num_log]
+        num_phy: total number of experts after replication
+    
+    Returns:
+        phy2log: [X, num_phy], logical expert id of each physical expert
+        rank: [X, num_phy], the replica rank
+        logcnt: [X, num_log], number of replicas for each logical expert
+    """
+    n, num_log = weight.shape
+    num_redundant = num_phy - num_log
+    assert num_redundant >= 0
+    device = weight.device
+    phy2log = torch.arange(num_phy, dtype=torch.int64,
+                           device=device).repeat(n, 1)
+    rank = torch.zeros(n, num_phy, dtype=torch.int64, device=device)
+    logcnt = torch.ones(n, num_log, dtype=torch.int64, device=device)
+    arangen = torch.arange(n, dtype=torch.int64, device=device)
+    for i in range(num_log, num_phy):
+        redundant_indices = (weight / logcnt).max(dim=-1).indices
+        phy2log[:, i] = redundant_indices
+        rank[:, i] = logcnt[arangen, redundant_indices]
+        logcnt[arangen, redundant_indices] += 1
+    return phy2log, rank, logcnt
+
+
+def rebalance_experts_hierarchical(weight: torch.Tensor,
+                                   num_physical_experts: int, num_groups: int,
+                                   num_nodes: int, num_gpus: int):
+    """
+    Parameters:
+        weight: [num_moe_layers, num_logical_experts]
+        num_physical_experts: number of physical experts after replication
+        num_groups: number of expert groups
+        num_nodes: number of server nodes, where the intra-node network (e.g, NVLink) is faster
+        num_gpus: number of GPUs, must be a multiple of `num_nodes`
+
+    Returns: 
+        physical_to_logical_map: [num_moe_layers, num_physical_experts]
+        logical_to_physical_map: [num_moe_layers, num_logical_experts, X]
+        logical_count: [num_moe_layers, num_logical_experts]
+    """
+    num_layers, num_logical_experts = weight.shape
+    assert num_logical_experts % num_groups == 0
+    group_size = num_logical_experts // num_groups
+    assert num_groups % num_nodes == 0
+    groups_per_node = num_groups // num_nodes
+    assert num_gpus % num_nodes == 0
+    assert num_physical_experts % num_gpus == 0
+    phy_experts_per_gpu = num_physical_experts // num_gpus
+
+    def inverse(perm: torch.Tensor) -> torch.Tensor:
+        inv = torch.empty_like(perm)
+        inv.scatter_(
+            1, perm,
+            torch.arange(perm.size(1), dtype=torch.int64,
+                         device=perm.device).expand(perm.shape))
+        return inv
+
+    # Step 1: pack groups to nodes
+    tokens_per_group = weight.unflatten(-1, (num_groups, group_size)).sum(-1)
+    group_pack_index, group_rank_in_pack = balanced_packing(
+        tokens_per_group, num_nodes)
+    log2mlog = (((group_pack_index * groups_per_node + group_rank_in_pack) *
+                 group_size).unsqueeze(-1) +
+                torch.arange(group_size,
+                             dtype=torch.int64,
+                             device=group_pack_index.device)).flatten(-2)
+    mlog2log = inverse(log2mlog)
+
+    # Step 2: construct redundant experts within nodes
+    # [num_layers * num_nodes, num_logical_experts // num_nodes]
+    tokens_per_mlog = weight.gather(-1, mlog2log).view(
+        -1, num_logical_experts // num_nodes)
+    phy2mlog, phyrank, mlogcnt = replicate_experts(
+        tokens_per_mlog, num_physical_experts // num_nodes)
+
+    # Step 3: pack physical_experts to GPUs
+    # [num_layers * num_nodes, num_physical_experts // num_nodes]
+    tokens_per_phy = (tokens_per_mlog / mlogcnt).gather(-1, phy2mlog)
+    pack_index, rank_in_pack = balanced_packing(tokens_per_phy,
+                                                num_gpus // num_nodes)
+    phy2pphy = pack_index * phy_experts_per_gpu + rank_in_pack
+    pphy2phy = inverse(phy2pphy)
+
+    pphy2mlog = phy2mlog.gather(
+        -1, pphy2phy)  # [num_layers * num_nodes, num_log_per_nodes]
+    pphy2mlog = (pphy2mlog.view(num_layers, num_nodes, -1) + torch.arange(
+        0,
+        num_logical_experts,
+        num_logical_experts // num_nodes,
+        device=group_pack_index.device).view(1, -1, 1)).flatten(-2)
+    pphy2log = mlog2log.gather(-1, pphy2mlog)
+    pphyrank = phyrank.gather(-1, pphy2phy).view(num_layers, -1)
+    logcnt = mlogcnt.view(num_layers, -1).gather(-1, log2mlog)
+    return pphy2log, pphyrank, logcnt
+
+
+def rebalance_experts(
+        weight: torch.Tensor, num_replicas: int, num_groups: int,
+        num_nodes: int,
+        num_gpus: int) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor]:
+    """
+    Entry point for expert-parallelism load balancer.
+
+    Parameters:
+        weight: [layers, num_logical_experts], the load statistics for all logical experts
+        num_replicas: number of physical experts, must be a multiple of `num_gpus`
+        num_groups: number of expert groups
+        num_nodes: number of server nodes, where the intra-node network (e.g, NVLink) is faster
+        num_gpus: number of GPUs, must be a multiple of `num_nodes`
+
+    Returns: 
+        physical_to_logical_map: [layers, num_replicas], the expert index of each replica
+        logical_to_physical_map: [layers, num_logical_experts, X], the replica indices for each expert
+        expert_count: [layers, num_logical_experts], number of physical replicas for each logical expert
+    """
+    num_layers, num_logical_experts = weight.shape
+    weight = weight.float().cpu()
+    if num_groups % num_nodes == 0:
+        # use hierarchical load-balance policy
+        phy2log, phyrank, logcnt = rebalance_experts_hierarchical(
+            weight, num_replicas, num_groups, num_nodes, num_gpus)
+    else:
+        # use global load-balance policy
+        phy2log, phyrank, logcnt = rebalance_experts_hierarchical(
+            weight, num_replicas, 1, 1, num_gpus)
+    maxlogcnt = logcnt.max().item()
+    log2phy: torch.Tensor = torch.full(
+        (num_layers, num_logical_experts, maxlogcnt),
+        -1,
+        dtype=torch.int64,
+        device=logcnt.device)
+    log2phy.view(num_layers, -1).scatter_(
+        -1, phy2log * maxlogcnt + phyrank,
+        torch.arange(num_replicas, dtype=torch.int64,
+                     device=log2phy.device).expand(num_layers, -1))
+    return phy2log, log2phy, logcnt
+
+
+__all__ = ['rebalance_experts']