Files
ai-toolkit/toolkit/memory_management/manager_modules.py
2025-11-17 18:04:00 +00:00

648 lines
23 KiB
Python

"""
This code was heavily inspired by the work of Lodestone-Rock, pretty much all credit goes
to them. The original code can be found here:
https://github.com/lodestone-rock/RamTorch/blob/main/ramtorch/modules/linear.py
I simply modified it to work with a memory management model and with AI Toolkit's models
"""
import torch
import torch.nn as nn
import torch.nn.functional as F
from typing import TYPE_CHECKING, Optional, Tuple
from torch.overrides import has_torch_function_unary # (ADD) torchao detection
if TYPE_CHECKING:
from .manager import MemoryManager
# --- Per-device global state registry ---
_DEVICE_STATE = {}
def _get_device_state(device: torch.device):
"""Get or initialize per-device state."""
if isinstance(device, str):
device = torch.device(device)
# CPU path needs no CUDA state
if device.type != "cuda":
if device not in _DEVICE_STATE:
_DEVICE_STATE[device] = {}
return _DEVICE_STATE[device]
if device not in _DEVICE_STATE:
with torch.cuda.device(device):
_DEVICE_STATE[device] = {
# streams & events
"transfer_stream": torch.cuda.Stream(device=device),
"transfer_grad_stream": torch.cuda.Stream(device=device),
"transfer_forward_finished_event": torch.cuda.Event(),
"compute_forward_start_event": torch.cuda.Event(),
"transfer_backward_finished_event": torch.cuda.Event(),
"transfer_weight_backward_finished_event": torch.cuda.Event(),
"compute_backward_start_event": torch.cuda.Event(),
"compute_backward_finished_event": torch.cuda.Event(),
# ping-pong buffers
"w_buffers": [None, None],
"b_buffers": [None, None],
"w_bwd_buffers": [None, None],
# device-side staging for grads to be sent to CPU
"w_grad_buffers": [None, None],
"b_grad_buffers": [None, None],
# clocks
"forward_clk": 0,
"backward_clk": 0,
}
return _DEVICE_STATE[device]
# (ADD) detect torchao wrapper tensors
def _is_ao_quantized_tensor(t: Optional[torch.Tensor]) -> bool:
if t is None:
return False
try:
if has_torch_function_unary(t):
return t.__class__.__module__.startswith("torchao.")
except Exception:
pass
for attr in (
"_scale",
"_scales",
"_zero_point",
"_zp",
"_block_size",
"_group_size",
"_pack_dim",
):
if hasattr(t, attr):
return True
return False
def _is_quantized_tensor(t: Optional[torch.Tensor]) -> bool:
if t is None:
return False
# torch quantized tensors
try:
if torch.is_quantized(t): # type: ignore[attr-defined]
return True
except Exception:
pass
# (ADD) torchao quantized wrappers
if _is_ao_quantized_tensor(t):
return True
# packed/int formats (weight-only)
return not t.dtype.is_floating_point
def _ensure_cpu_pinned(t: Optional[torch.Tensor]) -> Optional[torch.Tensor]:
if t is None:
return None
if t.device.type != "cpu":
try:
t = t.to("cpu", copy=True)
except Exception:
t = t.to("cpu")
# Don't attempt to pin quantized tensors; many backends don't support it
if _is_quantized_tensor(t):
return t
if torch.cuda.is_available():
try:
t = t.pin_memory()
except RuntimeError:
pass
return t
def _move_params_to_cpu_and_pin(module: nn.Module):
"""Force parameters to CPU (+pinned) so we can 'bounce' them per forward/backward."""
with torch.no_grad():
if hasattr(module, "weight") and isinstance(module.weight, nn.Parameter):
module.weight.data = _ensure_cpu_pinned(module.weight.data).detach()
if hasattr(module, "bias") and isinstance(module.bias, nn.Parameter):
if module.bias is not None:
module.bias.data = _ensure_cpu_pinned(module.bias.data).detach()
# ==========================
# Autograd functions (CUDA)
# ==========================
class _BouncingLinearFn(torch.autograd.Function):
@staticmethod
def forward(ctx, x, weight_cpu, bias_cpu, device: torch.device):
# choose compute dtype to match activations
target_dtype = (
x.dtype
if x.dtype in (torch.bfloat16, torch.float16, torch.float32)
else torch.bfloat16
)
# GPU-side dequant/cast for quantized; float path unchanged
def _materialize_linear_weight(cpu_w, dev):
if _is_quantized_tensor(cpu_w):
# move quantized wrapper to GPU -> dequantize on GPU -> cast on GPU
w_q_gpu = cpu_w.to(dev, non_blocking=True)
try:
w_fp_gpu = w_q_gpu.dequantize()
except Exception:
w_fp_gpu = w_q_gpu.to(dtype=torch.float32, non_blocking=True)
if w_fp_gpu.dtype != target_dtype:
w_fp_gpu = w_fp_gpu.to(target_dtype, non_blocking=True)
return w_fp_gpu
# float path (preserve original behavior: NO dtype cast)
w_gpu = cpu_w.to(dev, non_blocking=True)
return w_gpu
if device.type != "cuda":
out = F.linear(
x.to("cpu"),
_materialize_linear_weight(weight_cpu, torch.device("cpu")),
bias_cpu,
)
ctx.save_for_backward(x.to("cpu"), weight_cpu, bias_cpu)
ctx.device = torch.device("cpu")
return out.to(x.device)
state = _get_device_state(device)
ts = state["transfer_stream"]
w_bufs, b_bufs = state["w_buffers"], state["b_buffers"]
ev_tx_f = state["transfer_forward_finished_event"]
ev_cu_s = state["compute_forward_start_event"]
idx = state["forward_clk"]
with torch.cuda.stream(ts):
ts.wait_event(ev_cu_s)
w_bufs[idx] = _materialize_linear_weight(weight_cpu, device)
b_bufs[idx] = (
bias_cpu.to(device, non_blocking=True) if bias_cpu is not None else None
)
state["forward_clk"] ^= 1
ev_tx_f.record()
torch.cuda.current_stream().wait_event(ev_tx_f)
ev_cu_s.record()
out = F.linear(x, w_bufs[idx], b_bufs[idx])
ctx.save_for_backward(x, weight_cpu, bias_cpu)
ctx.device = device
ctx.target_dtype = target_dtype
return out
@staticmethod
def backward(ctx, grad_out):
x, weight_cpu, bias_cpu = ctx.saved_tensors
device = ctx.device
target_dtype = getattr(ctx, "target_dtype", grad_out.dtype)
if device.type != "cuda":
go_cpu = grad_out.to("cpu")
x_cpu = x.to("cpu")
w_mat = (
weight_cpu.dequantize()
if _is_quantized_tensor(weight_cpu)
else weight_cpu
)
if w_mat.dtype != target_dtype and target_dtype in (
torch.bfloat16,
torch.float16,
torch.float32,
):
w_mat = w_mat.to(target_dtype)
grad_input = go_cpu @ w_mat
grad_weight = (
go_cpu.flatten(0, -2).T @ x_cpu.flatten(0, -2)
if getattr(weight_cpu, "requires_grad", False)
and weight_cpu.dtype.is_floating_point
else None
)
grad_bias = (
go_cpu.sum(dim=tuple(range(go_cpu.ndim - 1)))
if (bias_cpu is not None and getattr(bias_cpu, "requires_grad", False))
else None
)
return grad_input.to(grad_out.device), grad_weight, grad_bias, None
state = _get_device_state(device)
transfer_stream = state["transfer_stream"]
transfer_grad_stream = state["transfer_grad_stream"]
w_bwd_buffers = state["w_bwd_buffers"]
w_grad_buffers = state["w_grad_buffers"]
b_grad_buffers = state["b_grad_buffers"]
ev_tx_b = state["transfer_backward_finished_event"]
ev_tx_w_bwd_done = state["transfer_weight_backward_finished_event"]
ev_cu_b_start = state["compute_backward_start_event"]
ev_cu_b_finish = state["compute_backward_finished_event"]
idx = state["backward_clk"]
# GPU-side dequant/cast for quantized; float path unchanged
def _materialize_for_bwd(cpu_w):
if _is_quantized_tensor(cpu_w):
w_q_gpu = cpu_w.to(device, non_blocking=True)
try:
w_fp_gpu = w_q_gpu.dequantize()
except Exception:
w_fp_gpu = w_q_gpu.to(dtype=torch.float32, non_blocking=True)
if w_fp_gpu.dtype != target_dtype:
w_fp_gpu = w_fp_gpu.to(target_dtype, non_blocking=True)
return w_fp_gpu
# float path (preserve original behavior: NO dtype cast)
w = cpu_w.to(device, non_blocking=True)
return w
with torch.cuda.stream(transfer_stream):
transfer_stream.wait_event(ev_cu_b_start)
w_bwd_buffers[idx] = _materialize_for_bwd(weight_cpu)
state["backward_clk"] ^= 1
ev_tx_b.record()
torch.cuda.current_stream().wait_event(ev_tx_b)
ev_cu_b_start.record()
# grad wrt input (GPU)
grad_input = grad_out.to(dtype=target_dtype) @ w_bwd_buffers[idx]
# ensure previous grad-to-CPU transfer that used this slot finished
torch.cuda.current_stream().wait_event(ev_tx_w_bwd_done)
# compute grads if float masters exist
grad_weight = None
grad_bias = None
if (
getattr(weight_cpu, "requires_grad", False)
and weight_cpu.dtype.is_floating_point
):
w_grad_buffers[idx] = grad_out.flatten(0, -2).T @ x.flatten(0, -2)
if bias_cpu is not None and getattr(bias_cpu, "requires_grad", False):
reduce_dims = tuple(range(grad_out.ndim - 1))
b_grad_buffers[idx] = grad_out.sum(dim=reduce_dims)
ev_cu_b_finish.record()
with torch.cuda.stream(transfer_grad_stream):
transfer_grad_stream.wait_event(ev_cu_b_finish)
if (
getattr(weight_cpu, "requires_grad", False)
and weight_cpu.dtype.is_floating_point
):
grad_weight = w_grad_buffers[idx].to("cpu", non_blocking=True)
if bias_cpu is not None and getattr(bias_cpu, "requires_grad", False):
grad_bias = b_grad_buffers[idx].to("cpu", non_blocking=True)
state["transfer_weight_backward_finished_event"].record()
return grad_input.to(dtype=grad_out.dtype), grad_weight, grad_bias, None
class _BouncingConv2dFn(torch.autograd.Function):
@staticmethod
def forward(
ctx,
x,
weight_cpu,
bias_cpu,
device: torch.device,
stride: Tuple[int, int],
padding: Tuple[int, int],
dilation: Tuple[int, int],
groups: int,
):
target_dtype = (
x.dtype
if x.dtype in (torch.bfloat16, torch.float16, torch.float32)
else torch.bfloat16
)
# GPU-side dequant/cast for quantized; float path unchanged
def _materialize_conv_weight(cpu_w, dev):
if _is_quantized_tensor(cpu_w):
w_q_gpu = cpu_w.to(dev, non_blocking=True)
try:
w_fp_gpu = w_q_gpu.dequantize()
except Exception:
w_fp_gpu = w_q_gpu.to(dtype=torch.float32, non_blocking=True)
if w_fp_gpu.dtype != target_dtype:
w_fp_gpu = w_fp_gpu.to(target_dtype, non_blocking=True)
return w_fp_gpu
# float path (preserve original behavior: NO dtype cast)
w_gpu = cpu_w.to(dev, non_blocking=True)
return w_gpu
if device.type != "cuda":
out = F.conv2d(
x.to("cpu"),
_materialize_conv_weight(weight_cpu, torch.device("cpu")),
bias_cpu,
stride,
padding,
dilation,
groups,
)
ctx.save_for_backward(x.to("cpu"), weight_cpu, bias_cpu)
ctx.meta = ("cpu", stride, padding, dilation, groups, target_dtype)
return out.to(x.device)
state = _get_device_state(device)
ts = state["transfer_stream"]
w_bufs, b_bufs = state["w_buffers"], state["b_buffers"]
ev_tx_f = state["transfer_forward_finished_event"]
ev_cu_s = state["compute_forward_start_event"]
idx = state["forward_clk"]
with torch.cuda.stream(ts):
ts.wait_event(ev_cu_s)
w_bufs[idx] = _materialize_conv_weight(weight_cpu, device)
b_bufs[idx] = (
bias_cpu.to(device, non_blocking=True) if bias_cpu is not None else None
)
state["forward_clk"] ^= 1
ev_tx_f.record()
torch.cuda.current_stream().wait_event(ev_tx_f)
ev_cu_s.record()
out = F.conv2d(x, w_bufs[idx], b_bufs[idx], stride, padding, dilation, groups)
ctx.save_for_backward(x, weight_cpu, bias_cpu)
ctx.meta = (device, stride, padding, dilation, groups, target_dtype)
return out
@staticmethod
def backward(ctx, grad_out):
x, weight_cpu, bias_cpu = ctx.saved_tensors
device, stride, padding, dilation, groups, target_dtype = ctx.meta
if (
isinstance(device, torch.device) and device.type != "cuda"
) or device == "cpu":
go = grad_out.to("cpu")
x_cpu = x.to("cpu")
w_cpu = (
weight_cpu.dequantize()
if _is_quantized_tensor(weight_cpu)
else weight_cpu
)
if w_cpu.dtype != target_dtype and target_dtype in (
torch.bfloat16,
torch.float16,
torch.float32,
):
w_cpu = w_cpu.to(target_dtype)
from torch.nn.grad import conv2d_input, conv2d_weight # type: ignore
grad_input = conv2d_input(
x_cpu.shape,
w_cpu,
go,
stride=stride,
padding=padding,
dilation=dilation,
groups=groups,
)
grad_weight = (
conv2d_weight(
x_cpu,
w_cpu.shape,
go,
stride=stride,
padding=padding,
dilation=dilation,
groups=groups,
)
if getattr(weight_cpu, "requires_grad", False)
and weight_cpu.dtype.is_floating_point
else None
)
grad_bias = (
go.sum(dim=(0, 2, 3))
if (bias_cpu is not None and getattr(bias_cpu, "requires_grad", False))
else None
)
return (
grad_input.to(grad_out.device),
grad_weight,
grad_bias,
None,
None,
None,
None,
None,
)
state = _get_device_state(device)
transfer_stream = state["transfer_stream"]
transfer_grad_stream = state["transfer_grad_stream"]
w_bwd_buffers = state["w_bwd_buffers"]
w_grad_buffers = state["w_grad_buffers"]
b_grad_buffers = state["b_grad_buffers"]
ev_tx_b = state["transfer_backward_finished_event"]
ev_tx_w_bwd_done = state["transfer_weight_backward_finished_event"]
ev_cu_b_start = state["compute_backward_start_event"]
ev_cu_b_finish = state["compute_backward_finished_event"]
idx = state["backward_clk"]
# GPU-side dequant/cast for quantized; float path unchanged
def _materialize_for_bwd(cpu_w):
if _is_quantized_tensor(cpu_w):
w_q_gpu = cpu_w.to(device, non_blocking=True)
try:
w_fp_gpu = w_q_gpu.dequantize()
except Exception:
w_fp_gpu = w_q_gpu.to(dtype=torch.float32, non_blocking=True)
if w_fp_gpu.dtype != target_dtype:
w_fp_gpu = w_fp_gpu.to(target_dtype, non_blocking=True)
return w_fp_gpu
# float path (preserve original behavior: NO dtype cast)
w = cpu_w.to(device, non_blocking=True)
return w
# Stage weights for input-grad compute
with torch.cuda.stream(transfer_stream):
transfer_stream.wait_event(ev_cu_b_start)
w_bwd_buffers[idx] = _materialize_for_bwd(weight_cpu)
state["backward_clk"] ^= 1
ev_tx_b.record()
torch.cuda.current_stream().wait_event(ev_tx_b)
ev_cu_b_start.record()
from torch.nn.grad import conv2d_input, conv2d_weight # type: ignore
grad_input = conv2d_input(
x.shape,
w_bwd_buffers[idx],
grad_out.to(dtype=target_dtype),
stride=stride,
padding=padding,
dilation=dilation,
groups=groups,
)
# Ensure previous grad transfer that used this slot is done
torch.cuda.current_stream().wait_event(ev_tx_w_bwd_done)
# Compute heavy grads on GPU into staging buffers
grad_weight = None
grad_bias = None
if (
getattr(weight_cpu, "requires_grad", False)
and weight_cpu.dtype.is_floating_point
):
w_grad_buffers[idx] = conv2d_weight(
x,
weight_cpu.shape,
grad_out,
stride=stride,
padding=padding,
dilation=dilation,
groups=groups,
)
if bias_cpu is not None and getattr(bias_cpu, "requires_grad", False):
b_grad_buffers[idx] = grad_out.sum(dim=(0, 2, 3))
ev_cu_b_finish.record()
# Launch CPU copies on the dedicated grad stream (overlaps with next H2D)
with torch.cuda.stream(transfer_grad_stream):
transfer_grad_stream.wait_event(ev_cu_b_finish)
if (
getattr(weight_cpu, "requires_grad", False)
and weight_cpu.dtype.is_floating_point
):
grad_weight = w_grad_buffers[idx].to("cpu", non_blocking=True)
if bias_cpu is not None and getattr(bias_cpu, "requires_grad", False):
grad_bias = b_grad_buffers[idx].to("cpu", non_blocking=True)
state["transfer_weight_backward_finished_event"].record()
return (
grad_input.to(dtype=grad_out.dtype),
grad_weight,
grad_bias,
None,
None,
None,
None,
None,
)
class BaseLayerMemoryManager:
def __init__(
self,
module: nn.Module,
manager: "MemoryManager",
):
self.module: nn.Module = module
self.manager: "MemoryManager" = manager
@classmethod
def attach(cls, module: nn.Module, manager: "MemoryManager"):
if hasattr(module, "_layer_memory_manager"):
return
module._layer_memory_manager = cls(module, manager)
# mark parameters as memory managed
for param in module.parameters(recurse=False):
param._is_memory_managed = True
class LinearLayerMemoryManager(BaseLayerMemoryManager):
def __init__(
self,
module: nn.Module,
manager: "MemoryManager",
):
super().__init__(module, manager)
# 1) Move params to CPU + pin memory for fast H2D
_move_params_to_cpu_and_pin(self.module)
# 2) Hijack forward
if hasattr(self.module, "ara_lora_ref"):
# ARA, we need to replace the lora forward
self._original_forward = getattr(self.module.ara_lora_ref(), "org_forward")
else:
self._original_forward = getattr(self.module, "forward")
def _mm_forward(x, *args, **kwargs):
# ensure we only use expected signature (Linear: x)
if args or kwargs:
# fall back to original if a custom signature is used
return self._original_forward(x, *args, **kwargs)
weight_cpu = self.module.weight
bias_cpu = getattr(self.module, "bias", None)
device = self.manager.process_device
# NOTE: do NOT move params to device here; autograd fn streams & bounces them
return _BouncingLinearFn.apply(x, weight_cpu, bias_cpu, device)
if hasattr(self.module, "ara_lora_ref"):
self.module.ara_lora_ref().org_forward = _mm_forward
else:
self.module.forward = _mm_forward
self.module._memory_management_device = self.manager.process_device
class ConvLayerMemoryManager(BaseLayerMemoryManager):
def __init__(
self,
module: nn.Module,
manager: "MemoryManager",
):
super().__init__(module, manager)
# 1) Move params to CPU + pin memory for fast H2D
_move_params_to_cpu_and_pin(self.module)
# Cache static conv attributes from the module
stride = (
self.module.stride
if isinstance(self.module.stride, tuple)
else (self.module.stride, self.module.stride)
)
padding = (
self.module.padding
if isinstance(self.module.padding, tuple)
else (self.module.padding, self.module.padding)
)
dilation = (
self.module.dilation
if isinstance(self.module.dilation, tuple)
else (self.module.dilation, self.module.dilation)
)
groups = self.module.groups
# 2) Hijack forward
if hasattr(self.module, "ara_lora_ref"):
# ARA, we need to replace the lora forward
self._original_forward = getattr(self.module.ara_lora_ref(), "org_forward")
else:
self._original_forward = getattr(self.module, "forward")
def _mm_forward(x, *args, **kwargs):
# Support the typical Conv2d(x) call; if user passes uncommon extras, fallback.
if args or kwargs:
return self._original_forward(x, *args, **kwargs)
weight_cpu = self.module.weight
bias_cpu = getattr(self.module, "bias", None)
device = self.manager.process_device
return _BouncingConv2dFn.apply(
x, weight_cpu, bias_cpu, device, stride, padding, dilation, groups
)
if hasattr(self.module, "ara_lora_ref"):
self.module.ara_lora_ref().org_forward = _mm_forward
else:
self.module.forward = _mm_forward
self.module._memory_management_device = self.manager.process_device