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sglang/python/sglang/srt/sampling/sampling_batch_info.py

258 lines
9.1 KiB
Python

from __future__ import annotations
import dataclasses
import logging
import threading
from typing import TYPE_CHECKING, Callable, List, Optional
import torch
import sglang.srt.sampling.penaltylib as penaltylib
logger = logging.getLogger(__name__)
if TYPE_CHECKING:
from sglang.srt.managers.schedule_batch import ScheduleBatch
@dataclasses.dataclass
class SamplingBatchInfo:
# Batched sampling params
temperatures: torch.Tensor
top_ps: torch.Tensor
top_ks: torch.Tensor
min_ps: torch.Tensor
# All requests use greedy sampling
is_all_greedy: bool
# Dispatch in CUDA graph
need_min_p_sampling: bool
# Bias Tensors
vocab_size: int
grammars: Optional[List] = None
sampling_info_done: Optional[threading.Event] = None
logit_bias: torch.Tensor = None
vocab_mask: Optional[torch.Tensor] = None
apply_mask: Optional[Callable[[torch.Tensor, torch.Tensor], None]] = None
# Penalizer
penalizer_orchestrator: Optional[penaltylib.BatchedPenalizerOrchestrator] = None
linear_penalties: Optional[torch.Tensor] = None
scaling_penalties: Optional[torch.Tensor] = None
# Device
device: str = "cuda"
@classmethod
def from_schedule_batch(
cls, batch: ScheduleBatch, vocab_size: int, enable_overlap_schedule: bool
):
reqs = batch.reqs
device = batch.device
temperatures = (
torch.tensor(
[r.sampling_params.temperature for r in reqs],
dtype=torch.float,
)
.view(-1, 1)
.to(device, non_blocking=True)
)
top_ps = torch.tensor(
[r.sampling_params.top_p for r in reqs], dtype=torch.float
).to(device, non_blocking=True)
top_ks = torch.tensor(
[r.sampling_params.top_k for r in reqs], dtype=torch.int32
).to(device, non_blocking=True)
min_ps = torch.tensor(
[r.sampling_params.min_p for r in reqs], dtype=torch.float
).to(device, non_blocking=True)
ret = cls(
temperatures=temperatures,
top_ps=top_ps,
top_ks=top_ks,
min_ps=min_ps,
need_min_p_sampling=any(r.sampling_params.min_p > 0 for r in reqs),
is_all_greedy=all(r.sampling_params.top_k <= 1 for r in reqs),
vocab_size=vocab_size,
device=device,
)
# TODO (lianmin): `need_min_p_sampling` needs to be updated in filter and merge.
if enable_overlap_schedule:
# TODO (lianmin): Some penalizers such as frequency and presence depend on model outputs,
# so it is kind of tricky to make it work with overlap scheduler.
# It requires correcly updating the penalty logits before the sampling and syncing the events.
# We will support them later.
penalizers = {
penaltylib.BatchedMinNewTokensPenalizer,
}
if (
any(req.sampling_params.frequency_penalty != 0.0 for req in reqs)
or any(req.sampling_params.presence_penalty != 0.0 for req in reqs)
or any(req.sampling_params.repetition_penalty != 1.0 for req in reqs)
):
logger.warning(
"frequency_penalty, presence_penalty, and repetition_penalty are not supported "
"when using the default overlap scheduler. They will be ignored. "
"Please add `--disable-overlap` when launching the server if you need these features. "
"The speed will be slower in that case."
)
else:
penalizers = {
penaltylib.BatchedFrequencyPenalizer,
penaltylib.BatchedMinNewTokensPenalizer,
penaltylib.BatchedPresencePenalizer,
penaltylib.BatchedRepetitionPenalizer,
}
# Each penalizers will do nothing if they evaluate themselves as not required by looking at
# the sampling_params of the requests (See {_is_required()} of each penalizers). So this
# should not add hefty computation overhead other than simple checks.
#
# While we choose not to even create the class instances if they are not required, this
# could add additional complexity to the {ScheduleBatch} class, especially we need to
# handle {filter_batch()} and {merge_batch()} cases as well.
ret.penalizer_orchestrator = penaltylib.BatchedPenalizerOrchestrator(
vocab_size=vocab_size,
batch=batch,
device=batch.device,
Penalizers=penalizers,
)
# Handle logit bias but only allocate when needed
ret.logit_bias = None
return ret
def __len__(self):
return len(self.temperatures)
def update_penalties(self):
self.scaling_penalties = None
self.linear_penalties = None
for penalizer in self.penalizer_orchestrator.penalizers.values():
if not penalizer.is_prepared():
continue
if isinstance(penalizer, penaltylib.BatchedRepetitionPenalizer):
self.scaling_penalties = penalizer.cumulated_repetition_penalties
else:
if self.linear_penalties is None:
bs = self.penalizer_orchestrator.batch.batch_size()
self.linear_penalties = torch.zeros(
(bs, self.vocab_size),
dtype=torch.float32,
device=self.device,
)
self.linear_penalties = penalizer.apply(self.linear_penalties)
def update_regex_vocab_mask(self):
if not self.grammars:
self.vocab_mask = None
self.apply_mask = None
return
# find a grammar from the list
first_grammar = next(grammar for grammar in self.grammars if grammar)
# maybe we can reuse the existing mask?
self.vocab_mask = first_grammar.allocate_vocab_mask(
vocab_size=self.vocab_size,
batch_size=len(self.temperatures),
device=self.device,
)
self.apply_mask = first_grammar.apply_vocab_mask # force to use static method
# Apply the mask
for i, grammar in enumerate(self.grammars):
if grammar and not grammar.finished:
grammar.fill_vocab_mask(self.vocab_mask, i)
# Move the mask to the device if needed
self.vocab_mask = first_grammar.move_vocab_mask(self.vocab_mask, self.device)
def filter_batch(self, unfinished_indices: List[int], new_indices: torch.Tensor):
self.penalizer_orchestrator.filter(unfinished_indices, new_indices)
for item in [
"temperatures",
"top_ps",
"top_ks",
"min_ps",
"logit_bias",
]:
value = getattr(self, item, None)
if value is not None: # logit_bias can be None
setattr(self, item, value[new_indices])
@staticmethod
def merge_bias_tensor(
lhs: torch.Tensor,
rhs: torch.Tensor,
bs1: int,
bs2: int,
device: str,
default: int = 0,
):
# bias tensor can be None
if lhs is not None or rhs is not None:
shape, dtype = None, None
if lhs is not None:
shape, dtype = lhs.shape[1:], lhs.dtype
else:
shape, dtype = rhs.shape[1:], rhs.dtype
with torch.dtype(dtype):
if lhs is None:
lhs = torch.empty((bs1, *shape), device=device).fill_(default)
if rhs is None:
rhs = torch.empty((bs2, *shape), device=device).fill_(default)
return torch.cat([lhs, rhs])
return None
def merge_batch(self, other: "SamplingBatchInfo"):
self.penalizer_orchestrator.merge(other.penalizer_orchestrator)
for item in [
"temperatures",
"top_ps",
"top_ks",
"min_ps",
]:
self_val = getattr(self, item, None)
other_val = getattr(other, item, None)
setattr(self, item, torch.concat([self_val, other_val]))
self.is_all_greedy = self.is_all_greedy and other.is_all_greedy
self.logit_bias = SamplingBatchInfo.merge_bias_tensor(
self.logit_bias, other.logit_bias, len(self), len(other), self.device
)
def apply_logits_bias(self, logits: torch.Tensor):
# Apply logit_bias
if self.logit_bias is not None:
logits.add_(self.logit_bias)
# min-token, presence, frequency
if self.linear_penalties is not None:
logits.add_(self.linear_penalties)
# repetition
if self.scaling_penalties is not None:
logits = torch.where(
logits > 0,
logits / self.scaling_penalties,
logits * self.scaling_penalties,
)
# Apply regex vocab_mask
if self.vocab_mask is not None:
self.apply_mask(logits=logits, vocab_mask=self.vocab_mask)
return logits