Eagle speculative decoding part 4: Add EAGLE2 worker (#2150)

Co-authored-by: kavioyu <kavioyu@tencent.com>
Co-authored-by: Lianmin Zheng <lianminzheng@gmail.com>

examples/runtime/engine/EAGLE_offline_batch_inference.py

+import sglang as sgl
+
+
+def main():
+    # Sample prompts.
+    prompts = [
+        "Hello, my name is",
+        "The president of the United States is",
+        "The capital of France is",
+        "The future of AI is",
+    ]
+
+    # Create a sampling params object.
+    sampling_params = {"temperature": 0, "max_new_tokens": 30}
+
+    # Create an LLM.
+    llm = sgl.Engine(
+        model_path="meta-llama/Llama-2-7b-chat-hf",
+        speculative_algorithm="EAGLE",
+        speculative_draft_model_path="lmzheng/sglang-EAGLE-llama2-chat-7B",
+        speculative_num_steps=3,
+        speculative_eagle_topk=4,
+        speculative_num_draft_tokens=16,
+    )
+
+    outputs = llm.generate(prompts, sampling_params)
+
+    # Print the outputs.
+    for prompt, output in zip(prompts, outputs):
+        print("===============================")
+        print(f"Prompt: {prompt}\nGenerated text: {output['text']}")
+
+
+# The __main__ condition is necessary here because we use "spawn" to create subprocesses
+# Spawn starts a fresh program every time, if there is no __main__, it will run into infinite loop to keep spawning processes from sgl.Engine
+if __name__ == "__main__":
+    main()

python/sglang/srt/speculative/build_eagle_tree.py

+import cutex
+import torch
+
+# parent_table [bs,topk*depth+)]
+# selected_index [bs,draft_token_num-1)]
+# verified_seq_len [bs]
+# tree_mask [draft_token*(seq_len[0]+draft_token) | draft_token*(seq_len[1]+draft_token) | ..] = [sum(verified_seq_len)*draft_token+bs*draft_token*draft_token]
+# positions [bs*draft_token]
+# retrive_index [b, draft_token, depth+2]
+kernels = cutex.SourceModule(
+    """
+//cuda
+__global__ void build_tree(Tensor<long, 2> parent_list, Tensor<long, 2> selected_index, Tensor<int, 1> verified_seq_len,
+        Tensor<bool, 1> tree_mask, Tensor<long, 1> positions, Tensor<long, 3> retrive_index, int topk, int depth, int draft_token_num) {
+        int bid = blockIdx.x;
+        int tid = threadIdx.x;
+        if (tid >= draft_token_num){
+            return;
+        }
+        int seq_tree_idx = draft_token_num * draft_token_num * bid;
+        for(int i=0; i<bid; i++){
+            seq_tree_idx += verified_seq_len[i] * draft_token_num;
+        }
+        int seq_len = verified_seq_len[bid];
+        int token_tree_idx = seq_tree_idx + (seq_len+draft_token_num)*tid + seq_len + 1;
+        for(int i=0; i<draft_token_num-1; i++){
+            tree_mask[token_tree_idx+i] = false;
+        }
+
+        int position = 0;
+        if (tid==0){
+            positions[bid*draft_token_num] = seq_len;
+            retrive_index[bid][0][0] = bid * draft_token_num;
+            return;
+        }
+
+        int depends_order[10];
+
+        int cur_position = tid-1;
+        while(true){
+            depends_order[position] = cur_position+1;
+            position += 1;
+            tree_mask[token_tree_idx+cur_position] = true;
+            int parent_tb_idx = selected_index[bid][cur_position]/topk;
+            if(parent_tb_idx==0){
+                break;
+            }
+
+            int token_idx = parent_list[bid][parent_tb_idx];
+            for(cur_position=0; cur_position<draft_token_num;cur_position++){
+                if(selected_index[bid][cur_position]==token_idx){
+                    break;
+                }
+            }
+        }
+        positions[bid*draft_token_num+tid] = position + seq_len;
+
+        int is_leaf = 0;
+        for(int i=1;i<draft_token_num;i++){
+            if(tree_mask[seq_tree_idx + i * (draft_token_num+seq_len) + seq_len + tid])
+            {
+                is_leaf ++;
+            }
+        }
+        if(is_leaf==1){
+            for(int i=0; i<position; i++){
+                retrive_index[bid][tid][position-i] = depends_order[i] + bid * draft_token_num;
+            }
+            retrive_index[bid][tid][0] = bid*draft_token_num;
+        }
+
+
+
+}
+//!cuda
+""",
+    float_bits=16,  # change to 16 to use half precision as `float` type in the above source code.
+    boundscheck=True,  # turning on for debug and off for performance (to use full threads of a block), default is on.
+)
+
+
+def build_tree_kernel(parent_list, top_score_index, seq_lens, topk, depth, draft_token):
+    bs = seq_lens.numel()
+    device = parent_list.device
+    tree_mask = torch.full(
+        (torch.sum(seq_lens).item() * draft_token + draft_token * draft_token * bs,),
+        True,
+        device=device,
+    )
+    retrive_index = torch.full(
+        (bs, draft_token, depth + 2), -1, device=device, dtype=torch.long
+    )
+    positions = torch.empty((bs * draft_token,), device=device, dtype=torch.long)
+
+    kernels.build_tree(
+        parent_list,
+        top_score_index,
+        seq_lens.to(torch.int32),
+        tree_mask,
+        positions,
+        retrive_index,
+        topk,
+        depth,
+        draft_token,
+        grid=(bs, 1, 1),
+        block=(64, 1, 1),
+    )
+    index = retrive_index.sum(dim=-1) != -depth - 2
+    cum_len = torch.cumsum(torch.sum(index, dim=-1), dim=-1)
+    retrive_cum_len = torch.zeros(
+        (cum_len.numel() + 1,), dtype=torch.int32, device="cuda"
+    )
+    retrive_cum_len[1:] = cum_len
+    retrive_index = retrive_index[index]
+    return tree_mask, positions, retrive_index, retrive_cum_len
+
+
+if __name__ == "__main__":
+
+    def findp(p_i, index, parent_list):
+        pos = index // 10
+        index_list = index.tolist()
+        parent_list = parent_list.tolist()
+        res = [p_i]
+        while True:
+            p = pos[p_i]
+            if p == 0:
+                break
+            token_idx = parent_list[p]
+            p_i = index_list.index(token_idx)
+            res.append(p_i)
+        return res
+
+    def create_mask(seq_len, draft_token, index, parent_list, max_depth):
+        mask = []
+        positions = []
+        retrive_index = []
+        for i, lens in enumerate(seq_len.tolist()):
+            first_mask = torch.full((lens + draft_token,), True)
+            first_mask[-(draft_token - 1) :] = False
+            positions.append(lens)
+            mask.append(first_mask)
+            seq_order = []
+            first_index = torch.Tensor([0] + [-1] * (depth + 1)).cuda().to(torch.long)
+            r_index = [first_index]
+            for j in range(draft_token - 1):
+                mask.append(torch.full((lens + 1,), True))
+                idx = findp(j, index, parent_list)
+
+                seq_order.append(idx)
+                positions.append(len(idx) + seq_len)
+                t = torch.full((draft_token - 1,), False)
+                t[idx] = True
+                mask.append(t)
+
+            for i in range(1, draft_token - 1):
+                is_leaf = 0
+                for j in range(draft_token - 1):
+                    if i in seq_order[j]:
+                        is_leaf += 1
+
+                if is_leaf == 1:
+                    order_list = [0] + [x + 1 for x in seq_order[i][::-1]]
+                    for _ in range(max_depth + 1 - len(seq_order[i])):
+                        order_list.append(-1)
+                    order = torch.Tensor(order_list).cuda().to(torch.long)
+                    r_index.append(order)
+            retrive_index.append(torch.stack(r_index))
+
+        return (
+            torch.cat(mask).cuda(),
+            torch.Tensor(positions).cuda().to(torch.long),
+            torch.stack(retrive_index),
+        )
+
+    index = (
+        torch.Tensor(
+            [
+                0,
+                1,
+                2,
+                3,
+                10,
+                11,
+                12,
+                13,
+                20,
+                21,
+                22,
+                30,
+                110,
+                130,
+                150,
+                160,
+                210,
+                211,
+                212,
+                213,
+                214,
+                215,
+                216,
+                217,
+                218,
+                219,
+                220,
+                230,
+                310,
+                311,
+                312,
+                313,
+                314,
+                315,
+                316,
+                317,
+                320,
+                321,
+                322,
+                330,
+                360,
+                380,
+                390,
+                410,
+                411,
+                412,
+                413,
+                414,
+                415,
+                416,
+                417,
+                418,
+                419,
+                420,
+                421,
+                422,
+                423,
+                430,
+                431,
+                440,
+                441,
+                460,
+                470,
+            ]
+        )
+        .to(torch.long)
+        .cuda()
+    )
+
+    parent_list = (
+        torch.Tensor(
+            [
+                -1,
+                0,
+                1,
+                2,
+                3,
+                4,
+                5,
+                6,
+                7,
+                8,
+                9,
+                10,
+                11,
+                12,
+                20,
+                30,
+                21,
+                13,
+                22,
+                40,
+                23,
+                110,
+                130,
+                160,
+                150,
+                190,
+                120,
+                111,
+                121,
+                200,
+                180,
+                210,
+                211,
+                212,
+                213,
+                214,
+                215,
+                216,
+                220,
+                230,
+                217,
+                310,
+                311,
+                312,
+                313,
+                320,
+                314,
+                321,
+                315,
+                316,
+                317,
+            ]
+        )
+        .to(torch.long)
+        .cuda()
+    )
+
+    verified_seq_len = torch.Tensor([47]).to(torch.long).cuda()
+    bs = verified_seq_len.shape[0]
+    topk = 10
+    depth = 5  # depth <= 10
+    draft_token = 64
+
+    tree_mask = torch.full(
+        (
+            torch.sum(verified_seq_len).item() * draft_token
+            + draft_token * draft_token * bs,
+        ),
+        True,
+    ).cuda()
+    retrive_index = torch.full(
+        (bs, draft_token, depth + 2), -1, device="cuda", dtype=torch.long
+    )
+    positions = torch.empty((bs * draft_token,), device="cuda", dtype=torch.long)
+
+    kernels.build_tree(
+        parent_list.unsqueeze(0),
+        index.unsqueeze(0),
+        verified_seq_len,
+        tree_mask,
+        positions,
+        retrive_index,
+        topk,
+        depth,
+        draft_token,
+        grid=(bs, 1, 1),
+        block=(64, 1, 1),
+    )
+    retrive_index = retrive_index[retrive_index.sum(dim=-1) != -depth - 2]
+
+    c_mask, c_positions, c_retive_index = create_mask(
+        verified_seq_len, draft_token, index, parent_list, depth
+    )
+
+    assert torch.allclose(tree_mask, c_mask), "tree mask has error."
+    assert torch.allclose(positions, c_positions), "positions has error."
+    assert torch.allclose(retrive_index, c_retive_index), "retrive_index has error."

python/sglang/srt/speculative/eagle_worker.py

+from typing import List, Optional, Union
+
+import torch
+
+from sglang.srt.layers.logits_processor import LogitsProcessorOutput
+from sglang.srt.managers.schedule_batch import Req, ScheduleBatch
+from sglang.srt.managers.tp_worker import TpModelWorker
+from sglang.srt.model_executor.forward_batch_info import (
+    CaptureHiddenMode,
+    ForwardBatch,
+    ForwardMode,
+)
+from sglang.srt.model_executor.model_runner import ModelRunner
+from sglang.srt.server_args import ServerArgs
+from sglang.srt.speculative.eagle_utils import EAGLEDraftInput
+
+
+class EAGLEWorker(TpModelWorker):
+
+    def __init__(
+        self,
+        server_args: ServerArgs,
+        gpu_id: int,
+        tp_rank: int,
+        dp_rank: Optional[int],
+        nccl_port: int,
+        target_worker: TpModelWorker,
+    ):
+        # Do not capture cuda graph in `super().__init__()`
+        # We will capture it later
+        backup_disable_cuda_graph = server_args.disable_cuda_graph
+        server_args.disable_cuda_graph = True
+        super().__init__(
+            gpu_id=gpu_id,
+            tp_rank=tp_rank,
+            server_args=server_args,
+            nccl_port=nccl_port,
+            dp_rank=dp_rank,
+            is_draft_worker=True,
+        )
+        self.target_worker = target_worker
+        self.server_args = server_args
+
+        # Share the embedding and lm_head
+        embed, head = self.target_worker.model_runner.model.get_embed_and_head()
+        self.model_runner.model.set_embed_and_head(embed, head)
+        self.model_runner.server_args.disable_cuda_graph = backup_disable_cuda_graph
+        self.model_runner.init_cuda_graphs()
+
+    def forward_draft_decode(self, batch: ScheduleBatch):
+        batch.spec_info.prepare_for_decode(batch)
+        model_worker_batch = batch.get_model_worker_batch()
+        forward_batch = ForwardBatch.init_new(model_worker_batch, self.model_runner)
+        forward_batch.spec_info.capture_hidden_mode = CaptureHiddenMode.LAST
+        logits_output = self.model_runner.forward(forward_batch)
+        self.capture_for_decode(logits_output, forward_batch)
+
+    def forward_draft_extend(self, batch: ScheduleBatch):
+        self._swap_mem_pool(batch, self.model_runner)
+        batch.spec_info.prepare_for_extend(batch)
+        model_worker_batch = batch.get_model_worker_batch()
+        forward_batch = ForwardBatch.init_new(model_worker_batch, self.model_runner)
+        forward_batch.spec_info.capture_hidden_mode = CaptureHiddenMode.LAST
+        logits_output = self.model_runner.forward(forward_batch)
+        self.capture_for_decode(logits_output, forward_batch)
+        self._swap_mem_pool(batch, self.target_worker.model_runner)
+
+    def forward_batch_speculative_generation(self, batch: ScheduleBatch):
+        if batch.forward_mode.is_decode():
+            prev_spec_info = batch.spec_info
+            self._swap_mem_pool(batch, self.model_runner)
+            for i in range(self.server_args.speculative_num_steps):
+                self.forward_draft_decode(batch)
+            batch.spec_info.clear_draft_cache(batch)
+            self._swap_mem_pool(batch, self.target_worker.model_runner)
+            (
+                next_draft_input,
+                logits_output,
+                verified_id,
+                self.finish_extend_len,
+                model_worker_batch,
+            ) = self.verify(batch)
+            next_draft_input.init(self.server_args)
+            batch.spec_info = next_draft_input
+            # if it is None, means all requsets are finished
+            if batch.spec_info.verified_id is not None:
+                self.forward_extend_after_decode(batch)
+            batch.spec_info = prev_spec_info
+            return logits_output, verified_id, model_worker_batch, next_draft_input
+
+        else:
+            spec_info = EAGLEDraftInput()
+            spec_info.init(self.server_args)
+            model_worker_batch = batch.get_model_worker_batch()
+            model_worker_batch.spec_info = spec_info
+            spec_info.capture_hidden_mode = CaptureHiddenMode.FULL
+            logits_output, next_token_ids = self.target_worker.forward_batch_generation(
+                model_worker_batch
+            )
+            model_worker_batch.spec_info.verified_id = next_token_ids
+            model_worker_batch.spec_info.hidden_states = logits_output.hidden_states
+            batch.spec_info = spec_info
+            self.forward_draft_extend(batch)
+            batch.spec_info = None
+            return logits_output, next_token_ids, model_worker_batch, spec_info
+
+    def verify(self, batch: ScheduleBatch):
+        verify_input = batch.spec_info.prepare_for_verify(batch)
+        batch.forward_mode = ForwardMode.TARGET_VERIFY
+        verify_input.prepare_for_verify(batch)
+        batch.spec_info = verify_input
+        batch.spec_info.capture_hidden_mode = CaptureHiddenMode.FULL
+        model_worker_batch = batch.get_model_worker_batch()
+        logits_output, _ = self.target_worker.forward_batch_generation(
+            model_worker_batch, skip_sample=True
+        )
+        verify_input.hidden_states = logits_output.hidden_states
+        res = verify_input.verify(batch, logits_output)
+        batch.forward_mode = ForwardMode.DECODE
+        return res + (model_worker_batch,)
+
+    def _swap_mem_pool(self, batch: ScheduleBatch, runner: ModelRunner):
+        batch.token_to_kv_pool = runner.token_to_kv_pool
+        batch.req_to_token_pool = runner.req_to_token_pool
+
+    def forward_extend_after_decode(self, batch: ScheduleBatch):
+        self._swap_mem_pool(batch, self.model_runner)
+        batch.forward_mode = ForwardMode.DRAFT_EXTEND
+        if batch.spec_info.has_finished:
+            index = batch.spec_info.unfinished_index
+            seq_lens = batch.seq_lens
+            batch.seq_lens = batch.seq_lens[index]
+        batch.spec_info.prepare_extend_after_decode(batch)
+        model_worker_batch = batch.get_model_worker_batch()
+        forward_batch = ForwardBatch.init_new(model_worker_batch, self.model_runner)
+        forward_batch.spec_info.capture_hidden_mode = CaptureHiddenMode.LAST
+        logits_output = self.model_runner.forward(forward_batch)
+        batch.spec_info.hidden_states = logits_output.hidden_states
+        self.capture_for_decode(logits_output, forward_batch)
+        batch.forward_mode = ForwardMode.DECODE
+        if batch.spec_info.has_finished:
+            batch.seq_lens = seq_lens
+        self._swap_mem_pool(batch, self.target_worker.model_runner)
+
+    def capture_for_decode(self, logits_output, forward_batch):
+        if isinstance(logits_output, LogitsProcessorOutput):
+            logits = logits_output.next_token_logits
+        sample_output = torch.softmax(
+            logits, dim=-1
+        )  # TODO: Support more sampling method @kavioyu
+        forward_batch.spec_info.capture_for_decode(
+            sample_output, logits_output.hidden_states, forward_batch.forward_mode
+        )
+
+    # Don't support prefix share now.
+    def finish_request(self, reqs: Union[Req, List[Req]]):
+        if not isinstance(reqs, List):
+            reqs = [reqs]
+        for req in reqs:
+            req_len = (
+                len(req.origin_input_ids)
+                + len(req.output_ids)
+                - self.finish_extend_len[req.rid]
+                - 1
+            )
+            kv_indices = self.model_runner.req_to_token_pool.req_to_token[
+                req.req_pool_idx
+            ][:req_len]
+            self.model_runner.token_to_kv_pool.free(kv_indices)
+            self.model_runner.req_to_token_pool.free(req.req_pool_idx)

test/srt/run_suite.py

@@ -13,6 +13,7 @@ suites = {
         "test_abort.py",
         "test_chunked_prefill.py",
         "test_double_sparsity.py",
+        "test_eagle_infer.py",
         "test_embedding_openai_server.py",
         "test_eval_accuracy_mini.py",
         "test_get_weights_by_name.py",

test/srt/test_eagle_infer.py

+import unittest
+
+import sglang as sgl
+
+
+class TestEAGLEEngine(unittest.TestCase):
+
+    def test_eagle_accuracy(self):
+        prompt = "Today is a sunny day and I like"
+        target_model_path = "meta-llama/Llama-2-7b-chat-hf"
+        speculative_draft_model_path = "lmzheng/sglang-EAGLE-llama2-chat-7B"
+
+        sampling_params = {"temperature": 0, "max_new_tokens": 8}
+
+        engine = sgl.Engine(
+            model_path=target_model_path,
+            speculative_draft_model_path=speculative_draft_model_path,
+            speculative_algorithm="EAGLE",
+            speculative_num_steps=3,
+            speculative_eagle_topk=4,
+            speculative_num_draft_tokens=16,
+        )
+        out1 = engine.generate(prompt, sampling_params)["text"]
+        engine.shutdown()
+
+        engine = sgl.Engine(model_path=target_model_path)
+        out2 = engine.generate(prompt, sampling_params)["text"]
+        engine.shutdown()
+
+        print("==== Answer 1 ====")
+        print(out1)
+
+        print("==== Answer 2 ====")
+        print(out2)
+        self.assertEqual(out1, out2)
+
+
+if __name__ == "__main__":
+    unittest.main()