Syncing FusedAdam with new Apex features (#3434)

* Updating fused adam with new Apex bf16 support.

* Removing capturable and master weight configs.

* resolving pr comments

---------

Co-authored-by: Olatunji Ruwase <olruwase@microsoft.com>
This commit is contained in:
Joe Mayer
2023-05-15 09:09:23 -07:00
committed by GitHub
parent 4716b0f769
commit 9685eb92ab

View File

@ -4,7 +4,7 @@
# DeepSpeed Team
"""
Copyright NVIDIA/apex
This file is adapted from fused adam in NVIDIA/apex, commit a109f85
This file is adapted from fused adam in NVIDIA/apex, commit 6bd01c4
"""
import torch
@ -18,13 +18,36 @@ from deepspeed.ops.op_builder import FusedAdamBuilder
class FusedAdam(torch.optim.Optimizer):
"""Implements Adam algorithm.
Currently GPU-only.
Currently GPU-only. Requires Apex to be installed via
``pip install -v --no-cache-dir --global-option="--cpp_ext" --global-option="--cuda_ext" ./``.
This version of fused Adam implements 2 fusions.
* Fusion of the Adam update's elementwise operations
* A multi-tensor apply launch that batches the elementwise updates applied to all the model's parameters into one or a few kernel launches.
:class:`apex.optimizers.FusedAdam` may be used as a drop-in replacement for ``torch.optim.AdamW``,
or ``torch.optim.Adam`` with ``adam_w_mode=False``::
opt = apex.optimizers.FusedAdam(model.parameters(), lr = ....)
...
opt.step()
:class:`apex.optimizers.FusedAdam` may be used with or without Amp. If you wish to use :class:`FusedAdam` with Amp,
you may choose any ``opt_level``::
opt = apex.optimizers.FusedAdam(model.parameters(), lr = ....)
model, opt = amp.initialize(model, opt, opt_level="O0" or "O1 or "O2")
...
opt.step()
In general, ``opt_level="O1"`` is recommended.
.. warning::
A previous version of :class:`FusedAdam` allowed a number of additional arguments to ``step``. These additional arguments
are now deprecated and unnecessary.
Adam was been proposed in `Adam: A Method for Stochastic Optimization`_.
Arguments:
@ -81,7 +104,7 @@ class FusedAdam(torch.optim.Optimizer):
else:
super(FusedAdam, self).zero_grad()
def step(self, closure=None, grads=None, output_params=None, scale=None, grad_norms=None):
def step(self, closure=None, grads=None, output_params=None, scale=None, grad_norms=None, grad_scaler=None):
"""Performs a single optimization step.
Arguments:
@ -99,14 +122,19 @@ class FusedAdam(torch.optim.Optimizer):
loss = closure()
for group in self.param_groups:
if len(group['params']) == 0:
continue
bias_correction = 1 if group['bias_correction'] else 0
beta1, beta2 = group['betas']
# assume same step across group now to simplify things
# per parameter step can be easily support by making it tensor, or pass list into kernel
if 'step' not in group:
group['step'] = 0
# create lists for multi-tensor apply
g_16, p_16, m_16, v_16 = [], [], [], []
g_bf, p_bf, m_bf, v_bf = [], [], [], []
g_32, p_32, m_32, v_32 = [], [], [], []
for p in group['params']:
@ -133,20 +161,32 @@ class FusedAdam(torch.optim.Optimizer):
p_16.append(p.data)
m_16.append(state['exp_avg'])
v_16.append(state['exp_avg_sq'])
elif p.dtype == torch.bfloat16:
g_bf.append(p.grad)
p_bf.append(p)
m_bf.append(state['exp_avg'])
v_bf.append(state['exp_avg_sq'])
elif p.dtype == torch.float32:
g_32.append(p.grad.data)
p_32.append(p.data)
m_32.append(state['exp_avg'])
v_32.append(state['exp_avg_sq'])
else:
raise RuntimeError('FusedAdam only support fp16 and fp32.')
raise RuntimeError('FusedAdam only support fp16, bf16 and fp32.')
if (len(g_16) > 0):
if len(g_16) > 0:
state['step'] += 1
multi_tensor_applier(self.multi_tensor_adam, self._dummy_overflow_buf, [g_16, p_16, m_16, v_16],
group['lr'], beta1, beta2, group['eps'], state['step'], self.adam_w_mode,
bias_correction, group['weight_decay'])
if (len(g_32) > 0):
if len(g_bf) > 0:
state['step'] += 1
multi_tensor_applier(self.multi_tensor_adam, self._dummy_overflow_buf, [g_bf, p_bf, m_bf, v_bf],
group['lr'], beta1, beta2, group['eps'], state['step'], self.adam_w_mode,
bias_correction, group['weight_decay'])
if len(g_32) > 0:
state['step'] += 1
multi_tensor_applier(self.multi_tensor_adam, self._dummy_overflow_buf, [g_32, p_32, m_32, v_32],
group['lr'], beta1, beta2, group['eps'], state['step'], self.adam_w_mode,