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A high-throughput and memory-efficient inference and serving engine for LLMs

Mirrored from https://github.com/tduncan-lum/Nvidia-Optimization-Stack---VLLM.git

Synced Nov 11, 22:30 UTC

[Model Runner V2] Support min-p sampling (#30171)

Signed-off-by: Woosuk Kwon <woosuk.kwon@berkeley.edu>

Woosuk Kwon committed Dec 5, 2025 at 21:42 UTC a238cbd89d07b4b0ed8fb3dff3c219a3ee3a1651
4 files changed +77
vllm/v1/worker/gpu/sample/metadata.py
+13
@@ -13,6 +13,7 @@ class SamplingMetadata:
13
14 top_p: torch.Tensor | None
15 top_k: torch.Tensor | None
16 + min_p: torch.Tensor | None
17
18 repetition_penalty: torch.Tensor
19 frequency_penalty: torch.Tensor
@@ -44,6 +45,7 @@ class SamplingMetadata:
45 # top_k = torch.full((num_reqs,), 20, dtype=torch.int32, device=device)
46 top_p = None
47 top_k = None
48 + min_p = torch.zeros(num_reqs, dtype=torch.float32, device=device)
49 # NOTE(woosuk): We must set penalties to their default values to make sure
50 # the penalties kernel does not touch the placeholder bin_counts tensors.
51 repetition_penalty = torch.ones(num_reqs, dtype=torch.float32, device=device)
@@ -64,6 +66,7 @@ class SamplingMetadata:
66 temperature=temperature,
67 top_p=top_p,
68 top_k=top_k,
69 + min_p=min_p,
70 repetition_penalty=repetition_penalty,
71 frequency_penalty=frequency_penalty,
72 presence_penalty=presence_penalty,
@@ -85,6 +88,8 @@ def _expand_sampling_metadata_kernel(
88 expanded_top_p_ptr,
89 top_k_ptr,
90 expanded_top_k_ptr,
91 + min_p_ptr,
92 + expanded_min_p_ptr,
93 rep_penalty_ptr,
94 expanded_rep_penalty_ptr,
95 freq_penalty_ptr,
@@ -115,6 +120,10 @@ def _expand_sampling_metadata_kernel(
120 top_k = tl.load(top_k_ptr + req_idx)
121 tl.store(expanded_top_k_ptr + start_idx + block, top_k, mask=mask)
122
123 + if min_p_ptr is not None:
124 + min_p = tl.load(min_p_ptr + req_idx)
125 + tl.store(expanded_min_p_ptr + start_idx + block, min_p, mask=mask)
126 +
127 rep_penalty = tl.load(rep_penalty_ptr + req_idx)
128 tl.store(expanded_rep_penalty_ptr + start_idx + block, rep_penalty, mask=mask)
129
@@ -138,6 +147,7 @@ def expand_sampling_metadata(
147 expanded_temp = create_empty(sampling_metadata.temperature)
148 expanded_top_p = create_empty(sampling_metadata.top_p)
149 expanded_top_k = create_empty(sampling_metadata.top_k)
150 + expanded_min_p = create_empty(sampling_metadata.min_p)
151 expanded_repetition_penalty = create_empty(sampling_metadata.repetition_penalty)
152 expanded_frequency_penalty = create_empty(sampling_metadata.frequency_penalty)
153 expanded_presence_penalty = create_empty(sampling_metadata.presence_penalty)
@@ -151,6 +161,8 @@ def expand_sampling_metadata(
161 expanded_top_p,
162 sampling_metadata.top_k,
163 expanded_top_k,
164 + sampling_metadata.min_p,
165 + expanded_min_p,
166 sampling_metadata.repetition_penalty,
167 expanded_repetition_penalty,
168 sampling_metadata.frequency_penalty,
@@ -166,6 +178,7 @@ def expand_sampling_metadata(
178 temperature=expanded_temp,
179 top_p=expanded_top_p,
180 top_k=expanded_top_k,
181 + min_p=expanded_min_p,
182 seeds=expanded_seeds,
183 repetition_penalty=expanded_repetition_penalty,
184 frequency_penalty=expanded_frequency_penalty,
vllm/v1/worker/gpu/sample/min_p.py new
+53
@@ -0,0 +1,53 @@
1 +# SPDX-License-Identifier: Apache-2.0
2 +# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
3 +import torch
4 +
5 +from vllm.triton_utils import tl, triton
6 +
7 +
8 +@triton.jit
9 +def _min_p_kernel(
10 + logits_ptr,
11 + logits_stride,
12 + min_p_ptr,
13 + vocab_size,
14 + BLOCK_SIZE: tl.constexpr,
15 +):
16 + req_idx = tl.program_id(0)
17 + min_p = tl.load(min_p_ptr + req_idx).to(tl.float32)
18 + if min_p == 0.0:
19 + return
20 +
21 + max_val = float("-inf")
22 + for i in range(0, vocab_size, BLOCK_SIZE):
23 + block = i + tl.arange(0, BLOCK_SIZE)
24 + mask = block < vocab_size
25 + logits = tl.load(
26 + logits_ptr + req_idx * logits_stride + block, mask=mask, other=float("-inf")
27 + )
28 + max_val = tl.max(tl.maximum(logits, max_val))
29 + max_val = max_val.to(tl.float32) # type: ignore
30 +
31 + threshold = max_val + tl.log(min_p)
32 + for i in range(0, vocab_size, BLOCK_SIZE):
33 + block = i + tl.arange(0, BLOCK_SIZE)
34 + mask = block < vocab_size
35 + logits = tl.load(
36 + logits_ptr + req_idx * logits_stride + block, mask=mask, other=float("-inf")
37 + )
38 + logits = tl.where(logits < threshold, float("-inf"), logits)
39 + tl.store(logits_ptr + req_idx * logits_stride + block, logits, mask=mask)
40 +
41 +
42 +def apply_min_p(logits: torch.Tensor, min_p: torch.Tensor | None) -> None:
43 + if min_p is None:
44 + return
45 + num_reqs, vocab_size = logits.shape
46 + BLOCK_SIZE = 1024
47 + _min_p_kernel[(num_reqs,)](
48 + logits,
49 + logits.stride(0),
50 + min_p,
51 + vocab_size,
52 + BLOCK_SIZE=BLOCK_SIZE,
53 + )
vllm/v1/worker/gpu/sample/sampler.py
+4
@@ -9,6 +9,7 @@ from vllm.v1.sample.ops.topk_topp_sampler import apply_top_k_top_p
9 from vllm.v1.worker.gpu.sample.gumbel import gumbel_sample
10 from vllm.v1.worker.gpu.sample.logprob import compute_topk_logprobs
11 from vllm.v1.worker.gpu.sample.metadata import SamplingMetadata
12 +from vllm.v1.worker.gpu.sample.min_p import apply_min_p
13 from vllm.v1.worker.gpu.sample.penalties import apply_penalties_and_temperature
14
15
@@ -61,6 +62,9 @@ class Sampler:
62
63 # Apply penalties and temperature in place.
64 apply_penalties_and_temperature(logits, sampling_metadata)
65 + # Apply min_p in place.
66 + apply_min_p(logits, sampling_metadata.min_p)
67 + # Apply top_k and/or top_p. This might return a new tensor.
68 logits = apply_top_k_top_p(
69 logits, sampling_metadata.top_k, sampling_metadata.top_p
70 )
vllm/v1/worker/gpu/states.py
+7
@@ -87,6 +87,7 @@ class RequestState:
87 self.temperature = self._make_param(self.max_num_reqs, torch.float32)
88 self.top_p = self._make_param(self.max_num_reqs, torch.float32)
89 self.top_k = self._make_param(self.max_num_reqs, torch.int32)
90 + self.min_p = self._make_param(self.max_num_reqs, torch.float32)
91 self.repetition_penalty = self._make_param(self.max_num_reqs, torch.float32)
92 self.frequency_penalty = self._make_param(self.max_num_reqs, torch.float32)
93 self.presence_penalty = self._make_param(self.max_num_reqs, torch.float32)
@@ -162,6 +163,7 @@ class RequestState:
163 else:
164 top_k = self.vocab_size
165 self.top_k.np[req_idx] = top_k
166 + self.min_p.np[req_idx] = sampling_params.min_p
167 self.repetition_penalty.np[req_idx] = sampling_params.repetition_penalty
168 self.frequency_penalty.np[req_idx] = sampling_params.frequency_penalty
169 self.presence_penalty.np[req_idx] = sampling_params.presence_penalty
@@ -217,6 +219,10 @@ class RequestState:
219 no_top_k = np.all(top_k == self.vocab_size)
220 top_k = self.top_k.copy_np_to_gpu(top_k) if not no_top_k else None
221
222 + min_p = self.min_p.np[idx_mapping_np]
223 + no_min_p = np.all(min_p == 0.0)
224 + min_p = self.min_p.copy_np_to_gpu(min_p) if not no_min_p else None
225 +
226 rep_penalty = self.repetition_penalty.np[idx_mapping_np]
227 rep_penalty = self.repetition_penalty.copy_np_to_gpu(rep_penalty)
228 freq_penalty = self.frequency_penalty.np[idx_mapping_np]
@@ -236,6 +242,7 @@ class RequestState:
242 temperature=temperature,
243 top_p=top_p,
244 top_k=top_k,
245 + min_p=min_p,
246 repetition_penalty=rep_penalty,
247 frequency_penalty=freq_penalty,
248 presence_penalty=pres_penalty,