Files
tinygrad/tinygrad/engine/jit.py
T
Philip SinitsinandGitHub 76c10cd635 jit: don't memplan buffers reachable from live tensors (#16588)
The memory planner was suballocating BUFFERs created during JIT capture that are still referenced by external lazy tensor graphs, like the .grad tensors assigned by backward(). The replay then only writes the arena slices, so realizing such a tensor after the call reads freshly allocated memory and silently returns zeros. Hold every BUFFER reachable from a live Tensor instead of only the parameters of the return value; true internals are still planned. Fixes #16571.
2026-06-12 17:51:54 +03:00

314 lines
16 KiB
Python

from typing import TypeVar, Generic, Callable, Any
import functools, collections
from tinygrad.tensor import Tensor, all_tensors
from tinygrad.helpers import flatten, merge_dicts, DEBUG, Context, BEAM, getenv, JIT, JIT_BATCH_SIZE, dedup, pluralize, VIZ
from tinygrad.device import Buffer, Compiled, Device, MultiBuffer
from tinygrad.dtype import DType, dtypes
from tinygrad.uop.ops import UOp, PatternMatcher, Variable, sym_infer, Ops, buffers, track_rewrites, graph_rewrite
from tinygrad.engine.realize import capturing, Estimates, compile_linear, run_linear, graph_cache, estimate_uop, get_runtime
from tinygrad.engine.realize import unwrap_multi, resolve_params, get_call_arg_uops, get_call_outs_ins
from tinygrad.schedule.memory import memory_plan_rewrite, _collect_bufs
from tinygrad.nn.state import get_parameters
from tinygrad.schedule.rangeify import mop_cleanup
from dataclasses import dataclass
def prune_linear(linear:UOp, needed:set[UOp]) -> tuple[UOp, UOp]:
kept, onetime = [], []
for si in linear.src:
si_bufs = {b for src in si.src[1:] for b in _collect_bufs(src)}
if not si_bufs.isdisjoint(needed):
kept.append(si)
needed |= si_bufs
else: onetime.append(si)
return linear.replace(src=tuple(kept)), linear.replace(src=tuple(onetime))
def create_graph_call(batch:list[UOp]) -> UOp:
# all external inputs are PARAMs
input_list = dedup(u for si in batch for b in si.src[1:] for u in b.toposort() if u.op is Ops.PARAM)
cf = UOp(Ops.CUSTOM_FUNCTION, dtypes.void, src=(UOp(Ops.LINEAR, src=tuple(batch)),), arg="graph")
return cf.call(*input_list, metadata=tuple(m for si in batch for m in si.arg.metadata))
def graph_split_rewrite(linear:UOp, max_batch_size:int=0) -> UOp:
new_src: list[UOp] = []
current_batch: list[UOp] = []
current_batch_devs: list[Compiled] = []
def flush_batch():
nonlocal current_batch, current_batch_devs, max_batch_size, new_src
if len(current_batch) <= 1 and not getenv("GRAPH_ONE_KERNEL"): new_src.extend(current_batch)
else:
new_src.append(create_graph_call(current_batch))
max_batch_size *= 2
if DEBUG >= 2: print(f"JIT GRAPHing batch with {len(current_batch)} kernels")
current_batch, current_batch_devs = [], []
for si in linear.src:
if si.src[0].op is Ops.SLICE: continue
devs = dedup([Device[x] for b in si.src[1:] if b.op is not Ops.BIND for x in (b.device if isinstance(b.device, tuple) else (b.device,))])
graph_t = graph_class(devs[0]) if devs[0].graph is not None else None
can_graph = graph_t is not None and graph_t.supports_uop(devs, si)
can_extend = can_graph and graph_t is not None and (not current_batch_devs or graph_t.supports_uop(current_batch_devs, si)) \
and (max_batch_size == 0 or len(current_batch) < max_batch_size)
if not can_extend and current_batch: flush_batch()
# append this si and update devs
(current_batch if can_graph else new_src).append(si)
current_batch_devs = dedup(current_batch_devs + devs) if can_graph else []
if current_batch: flush_batch()
return linear.replace(src=tuple(new_src))
def _copy_input(u:UOp) -> UOp:
run_linear(UOp(Ops.LINEAR, src=(u.copy_to_device(u.device).call(new:=UOp.new_buffer(u.device, u.arg, u.dtype), u, metadata=()),)))
return new
@track_rewrites(lambda linear,held_bufs,input_uops,ret=(): f"JIT {pluralize('call', len(linear.src))}")
def jit_lower(linear:UOp, held_bufs:set[UOp], input_uops:list[UOp]) -> UOp:
if VIZ: graph_rewrite(linear, PatternMatcher([]), name="View captured linear")
# parametrize input buffers: map each input buffer UOp to a PARAM with the correct slot index
linear = linear.substitute({u: UOp.param(i, u.dtype, u.shape, u.device) for i,u in enumerate(input_uops)}, walk=True)
linear = memory_plan_rewrite(linear, held_bufs)
linear = compile_linear(linear, beam=getenv("JITBEAM", BEAM.value))
if JIT < 2: linear = graph_split_rewrite(linear, max_batch_size=JIT_BATCH_SIZE.value)
if VIZ: graph_rewrite(linear, PatternMatcher([]), name="View graphed linear")
return linear
class GraphException(Exception): pass
class JitError(Exception): pass
def _check_no_non_tensor_return(ret):
if ret is None or isinstance(ret, Tensor): return
if isinstance(ret, (tuple, list, dict)):
for item in (ret.values() if isinstance(ret, dict) else ret): _check_no_non_tensor_return(item)
return
raise JitError(f"JIT return contains non-Tensor value of type {type(ret).__name__}")
def graph_class(dev): return dev.graph.func if isinstance(dev.graph, functools.partial) else dev.graph
class DepsTracker:
def __init__(self):
# tracks (offset, end, dep) ranges per base buffer id to handle suballocated buffers correctly.
self.w_dependency_map: dict[int, list[tuple[int, int, Any]]] = collections.defaultdict(list)
self.r_dependency_map: dict[int, list[tuple[int, int, Any]]] = collections.defaultdict(list)
@staticmethod
def _buf_key(buf:Buffer) -> int: return id(buf.base)
def access_resources(self, bufs:list[Buffer], write:list[int], new_dependency:Any):
wait_nodes = []
for i,buf in enumerate(bufs):
key, s, e = self._buf_key(buf), buf.offset, buf.offset + buf.nbytes
wait_nodes += [dep for st,en,dep in self.w_dependency_map[key] if st < e and s < en]
if i in write: wait_nodes += [dep for st,en,dep in self.r_dependency_map[key] if st < e and s < en]
for i,buf in enumerate(bufs):
key, s, e = self._buf_key(buf), buf.offset, buf.offset + buf.nbytes
if i in write:
for dmap in [self.w_dependency_map, self.r_dependency_map]:
kept = []
for st,en,dep in dmap[key]:
if st < min(s, en): kept.append((st, min(s, en), dep))
if max(e, st) < en: kept.append((max(e, st), en, dep))
dmap[key] = kept
self.w_dependency_map[key].append((s, e, new_dependency))
else: self.r_dependency_map[key].append((s, e, new_dependency))
return list({id(x):x for x in wait_nodes}.values())
class GraphRunner:
def __init__(self, linear:UOp, input_uops:tuple[UOp, ...]=()):
self.linear = linear.src[0]
self.calls: list[tuple[int, UOp, list[Buffer], dict[str, int]]] = []
self.runtimes: list[Any|None] = []
self.uop_replace: list[list[tuple[int, int]]] = []
for call in self.linear.src:
replace = [(p, b.arg.slot) for p, b in enumerate(get_call_arg_uops(call)) if b.op is Ops.PARAM]
for dev_idx, (bufs, device_vars) in enumerate(unwrap_multi(call, resolve_params(call, input_uops))):
self.calls.append((dev_idx, call.src[0], [b.ensure_allocated() for b in bufs], device_vars))
self.runtimes.append(get_runtime(bufs[0].device, call.src[0]) if call.src[0].op is Ops.PROGRAM else None)
self.uop_replace.append(replace)
self.var_vals_replace:dict[int, list[tuple[int, int]]] = {}
self.launch_dims_replace:dict[int, tuple[int|None, int|None]] = {}
self.launch_dims_base:dict[int, tuple[tuple[int|float, ...], tuple[int, ...]]] = {}
def is_sym_dim(dim) -> bool: return not all(isinstance(d, (int, float)) for d in dim)
crs = [(j, self.calls[j][1].arg, self.calls[j][3]) for j in range(len(self.calls)) if self.calls[j][1].op is Ops.PROGRAM]
self.vars = sorted({v.expr for _,p,dv in crs for v in p.vars if v.expr not in dv | p.runtimevars})
self.symbolic_dims = dedup(tuple(d) for _,p,_ in crs for d in (p.local_size, p.global_size) if d and is_sym_dim(d))
def find_symbolic_dim(dim): return self.symbolic_dims.index(tuple(dim)) if dim is not None and tuple(dim) in self.symbolic_dims else None
for j,p,dv in crs:
if (replace:=[(i, self.vars.index(v.expr)) for i, v in enumerate(p.vars) if v.expr not in dv | p.runtimevars]):
self.var_vals_replace[j] = replace
global_dim_idx, local_dim_idx = find_symbolic_dim(p.global_size), find_symbolic_dim(p.local_size)
if global_dim_idx is not None or local_dim_idx is not None:
self.launch_dims_replace[j] = (global_dim_idx, local_dim_idx)
assert p.local_size is not None
self.launch_dims_base[j] = (tuple(p.global_size), tuple(p.local_size))
estimates = sum((estimate_uop(call) for call in self.linear.src), Estimates())
# used in MultiGraphRunner
self.deps = DepsTracker()
self.device, self.estimates = self.calls[0][2][0].device.split(":")[0], estimates.simplify()
def __call__(self, input_uops:tuple[UOp, ...], var_vals:dict[str, int], wait=False) -> float|None: raise NotImplementedError("override this")
def updated_vars(self, var_vals: dict[str, int]):
vals = [var_vals[v] for v in self.vars]
for j, vidxs in self.var_vals_replace.items():
for i, v in vidxs: yield j, i, vals[v]
def updated_launch_dims(self, var_vals: dict[str, int]):
dims = [tuple(sym_infer(s, var_vals) for s in dim) for dim in self.symbolic_dims]
for j, (gl, lc) in self.launch_dims_replace.items():
yield j, (dims[gl] if gl is not None else self.launch_dims_base[j][0]), (dims[lc] if lc is not None else self.launch_dims_base[j][1])
def _access_resources(self, bufs:list[Buffer], write:list[int], new_dependency:Any):
return self.deps.access_resources(bufs, write, new_dependency)
@staticmethod
def _all_devs(batch_devs:list[Compiled], new_call:UOp) -> list[Compiled]:
return dedup(batch_devs + [Device[x] for b in get_call_arg_uops(new_call)
for x in (b.device if isinstance(b.device, tuple) else (b.device,))])
@staticmethod
def supports_uop(batch_devs:list[Compiled], new_call:UOp) -> bool:
return new_call.src[0].op is Ops.PROGRAM and len(GraphRunner._all_devs(batch_devs, new_call)) == 1
# a marker for your graph supporting multiple devices of the same type
class MultiGraphRunner(GraphRunner):
@staticmethod
def supports_uop(batch_devs:list[Compiled], new_call:UOp) -> bool:
# Devices must be the same type
return new_call.src[0].op in (Ops.PROGRAM, Ops.COPY) and len(dedup([type(d) for d in GraphRunner._all_devs(batch_devs, new_call)])) == 1
ReturnType = TypeVar('ReturnType')
@dataclass
class CapturedJit(Generic[ReturnType]):
ret: Any # includes the Tensors or any other returned object
linear: UOp
expected_names: list[int|str]
expected_input_info: list[tuple[UOp, tuple[Variable, ...], DType, str]] # (view, variables, dtype, device) per input
def __reduce__(self): return self.__class__, (self.ret, self.linear, self.expected_names, self.expected_input_info)
@functools.cached_property
def _written_uops(self) -> set[UOp]:
out: set[UOp] = set()
for call in self.linear.toposort():
if call.op is not Ops.CALL: continue
arg_uops = get_call_arg_uops(call)
outs, ins = get_call_outs_ins(call)
out |= {arg_uops[k] for k in set(outs) - set(ins) if arg_uops[k].op in (Ops.BUFFER, Ops.SLICE)}
return out
def __call__(self, input_uops:list[UOp], var_vals:dict[str, int]) -> ReturnType:
concrete = tuple(_copy_input(u) if u in self._written_uops else u for u in input_uops)
if DEBUG >= 1 and len(self.linear.src) >= 10: print(f"jit execs {len(self.linear.src)} calls")
run_linear(self.linear, var_vals, input_uops=concrete, jit=True)
return self.ret
def free_intermediates(self):
# drop graph runners
for call in self.linear.src:
if call.src[0].op is Ops.CUSTOM_FUNCTION and call.src[0].arg == "graph": graph_cache.pop(call.src[0], None)
for u in self._written_uops:
if (buf:=buffers.get(u)) is None: continue
for b in (buf.bufs if isinstance(buf, MultiBuffer) else (buf,)):
if b.is_initialized(): b.deallocate()
if (base:=b._base) is not None and base.allocated_views == 0 and base.is_allocated(): base.deallocate()
def _prepare_jit_inputs(args, kwargs):
input_tensors: list[tuple[int|str, Tensor]] = [(name,t) for name,t in list(enumerate(args))+sorted(kwargs.items()) if t.__class__ is Tensor]
names, tensors = [name for name,_ in input_tensors], [t for _,t in input_tensors]
# extract tensors from containers (shallow, not recursive to avoid grabbing model weights)
for x in args + tuple(kwargs.values()):
it = x if isinstance(x, (tuple,list)) else x.values() if isinstance(x, dict) else []
tensors += [t for t in it if t.__class__ is Tensor and not any(t is y for y in tensors)]
def get_input_uops() -> list[UOp]: return flatten([t.uop.src if t.uop.op is Ops.MULTI else [t.uop] for t in tensors])
# TODO: drop the CONST branch once all CONST are deviceless
if any(u.device is None or u.base.op is Ops.CONST for u in get_input_uops()): raise JitError("JIT inputs must be real buffers; use .clone()")
if len(unrealized_tensors := [x for x in tensors if not x.uop.is_realized]): Tensor.realize(*unrealized_tensors)
input_uops = get_input_uops()
# collect buffer UOps (including MultiBuffer)
input_buf_uops: list[UOp] = [u.base for u in input_uops if u.base.realized is not None]
if len(set(input_buf_uops)) != len(input_buf_uops): raise JitError("duplicate inputs to JIT")
inputs = [(*(u.substitute({u.base:UOp(Ops.NOOP)}, extra_pm=mop_cleanup).unbind_all()), u.dtype, u.device) for u in input_uops]
_var_vals = merge_dicts([x[1] for x in inputs] + [dict(v.unbind() for v in (args + tuple(kwargs.values())) if isinstance(v, UOp))])
var_vals = {k.expr:v for k,v in _var_vals.items()}
expected_input_info = [(x[0], tuple(sorted(x[1].keys(), key=lambda v: v.expr)), x[2], x[3]) for x in inputs]
return input_buf_uops, var_vals, names, expected_input_info
class TinyJit(Generic[ReturnType]):
def __init__(self, fxn:Callable[..., ReturnType]|None, captured:CapturedJit|None=None, prune=False):
assert fxn or captured, "need either a function or a CapturedJit"
self.fxn = fxn
self.captured: CapturedJit|None = captured
self.cnt: int = 2 if self.fxn is None else 0
self.prune = prune
def add_linear(self, linear:UOp, var_vals:dict[str, int]): self._linears.append(linear)
def reset(self):
assert self.fxn is not None, "can't reset without function"
self.cnt = 0
self.captured = None
def __reduce__(self):
assert self.captured is not None, "can't pickle an uncaptured JIT"
return self.__class__, (None, self.captured)
def __get__(self, obj, objtype): return functools.partial(self.__call__, obj) # add support for instance methods
def __call__(self, *args, **kwargs) -> ReturnType:
input_buf_uops, var_vals, names, expected_input_info = _prepare_jit_inputs(args, kwargs)
if not JIT or self.cnt == 0:
# jit ignore
assert self.fxn is not None
with Context(BEAM=0 if getenv("IGNORE_JIT_FIRST_BEAM") else BEAM.value):
ret = self.fxn(*args, **kwargs)
if len(params:=get_parameters(ret)): Tensor.realize(*params)
elif self.cnt == 1:
# jit capture
assert self.fxn is not None
if capturing: raise RuntimeError(f"having TinyJit inside another TinyJit is not supported {len(capturing)=} {capturing=}")
self._linears: list[UOp] = []
capturing.append(self)
try:
ret = self.fxn(*args, **kwargs)
if len(params:=get_parameters(ret)): Tensor.realize(*params)
finally: capturing.clear()
if not len(self._linears): raise JitError("didn't JIT anything!")
_check_no_non_tensor_return(ret)
if DEBUG >= 1: print(f"JIT captured {len(self._linears)} linears with {len(input_buf_uops)} inputs")
# combine all captured linears into one, memory plan, and graph split
big_linear = UOp(Ops.LINEAR, src=tuple(flatten([l.src for l in self._linears])))
del self._linears
if self.prune:
big_linear, onetime_linear = prune_linear(big_linear, set(input_buf_uops))
if DEBUG >= 1: print(f"pruned from {len(big_linear.src) + len(onetime_linear.src)} -> {len(big_linear.src)} kernels")
run_linear(onetime_linear, var_vals)
# hold all buffers reachable from live Tensors (e.g. lazy .grad created during capture), the memory planner can't suballocate those
held_bufs = set(buffers) | {u for tref in list(all_tensors) if (t:=tref()) is not None for u in t.uop.toposort() if u.op is Ops.BUFFER}
linear = jit_lower(big_linear, held_bufs, input_buf_uops)
self.captured = CapturedJit(ret, linear, names, expected_input_info)
ret = self.captured(input_buf_uops, var_vals)
elif self.cnt >= 2:
# jit exec
assert self.captured is not None
if self.captured.expected_names != names: raise JitError(f"args mismatch in JIT: {self.captured.expected_names=} != {names}")
if self.captured.expected_input_info != expected_input_info:
raise JitError(f"args mismatch in JIT: {self.captured.expected_input_info=} != {expected_input_info=}")
ret = self.captured(input_buf_uops, var_vals)
self.cnt += 1
return ret