[FSDP] How can I wrap a model that has both nn.Parameter and nn.Module
Labels: oncall: distributed, triaged, module: fsdp

### 🐛 Describe the bug

I recursively wrap a simple model for each module. And when I operate with the nn.Parameter it drop an error: "RuntimeError: Output 0 of ViewBackward0 is a view and its base or another view of its base has been modified inplace. This view is the output of a function that returns multiple views. Such functions do not allow the output views to be modified inplace. You should replace the inplace operation by an out-of-place one."  

```python
import os
import argparse
import functools
import torch
import torch.nn as nn
import torch.nn.functional as F
import torch.optim as optim
from torchvision import datasets, transforms


from torch.optim.lr_scheduler import StepLR

import torch.distributed as dist
import torch.multiprocessing as mp
from torch.nn.parallel import DistributedDataParallel as DDP
from torch.utils.data.distributed import DistributedSampler
from torch.distributed.fsdp import FullyShardedDataParallel as FSDP
from torch.distributed.fsdp.fully_sharded_data_parallel import (
    CPUOffload,
    BackwardPrefetch,
)
from torch.distributed.fsdp.wrap import (
    size_based_auto_wrap_policy,
    enable_wrap,
    wrap,
)

import torch.distributed as dist
import torch.multiprocessing as mp
from torch.nn.parallel import DistributedDataParallel as DDP
from torch.utils.data.distributed import DistributedSampler
from torch.distributed.fsdp import FullyShardedDataParallel as FSDP
from torch.distributed.fsdp.fully_sharded_data_parallel import (
    CPUOffload,
    BackwardPrefetch,
)
from torch.distributed.fsdp.wrap import (
    size_based_auto_wrap_policy,
    transformer_auto_wrap_policy,
    enable_wrap,
    wrap,
)

from torch.distributed.fsdp import (
CPUOffload,
MixedPrecision,
ShardingStrategy,
BackwardPrefetch,
)

import os


def setup(rank, world_size):
    os.environ['MASTER_ADDR'] = 'localhost'
    os.environ['MASTER_PORT'] = '32131'

    # initialize the process group
    dist.init_process_group("nccl", rank=rank, world_size=world_size)

def cleanup():
    dist.destroy_process_group()
    

class Attention(nn.Module):
    def __init__(self):
        super().__init__()
        self.qkv = nn.Linear(1, 13, bias=False)
        self.q_bias = nn.Parameter(torch.zeros(1,1,100))

class Net(nn.Module):
    def __init__(self):
        super(Net, self).__init__()
        self.test1 = nn.Parameter(torch.zeros(1, 1, 100))
        self.conv1 = nn.Conv2d(1, 32, 3, 1)
        self.conv2 = nn.Conv2d(32, 64, 3, 1)
        self.dropout1 = nn.Dropout(0.25)
        self.dropout2 = nn.Dropout(0.5)
        self.fc1 = nn.Linear(9216, 128)
        self.fc2 = nn.Linear(128, 10)
        self.attn = Attention()

    def forward(self, x):

        x = self.conv1(x)
        x = F.relu(x)
        x = self.conv2(x)
        x = F.relu(x)
        x = F.max_pool2d(x, 2)
        x = self.dropout1(x)
        x = torch.flatten(x, 1)
        x = self.fc1(x)
        x = F.relu(x)
        x = self.dropout2(x)
        x = self.fc2(x)
        output = F.log_softmax(x, dim=1)
        return output
    
    def parge_param_info(self):
        wrap_list = []
        non_wrap_list = []
        for n, _ in self.named_parameters():
            if not '.' in n:
                non_wrap_list.append(n)
            else:
                wrap_list.append(n)           
        return  wrap_list, non_wrap_list  
    
def train(args, model, rank, world_size, train_loader, optimizer, epoch, sampler=None):
    model.train()
    ddp_loss = torch.zeros(2).to(rank)
    if sampler:
        sampler.set_epoch(epoch)
    for batch_idx, (data, target) in enumerate(train_loader):
        data, target = data.to(rank), target.to(rank)
        optimizer.zero_grad()
        output = model(data)
        loss = F.nll_loss(output, target, reduction='sum')
        loss.backward()
        optimizer.step()
        ddp_loss[0] += loss.item()
        ddp_loss[1] += len(data)

    dist.all_reduce(ddp_loss, op=dist.ReduceOp.SUM)
    if rank == 0:
        print('Train Epoch: {} \tLoss: {:.6f}'.format(epoch, ddp_loss[0] / ddp_loss[1]))
        
        
def test(model, rank, world_size, test_loader):
    model.eval()
    correct = 0
    ddp_loss = torch.zeros(3).to(rank)
    with torch.no_grad():
        for data, target in test_loader:
            data, target = data.to(rank), target.to(rank)
            output = model(data)
            ddp_loss[0] += F.nll_loss(output, target, reduction='sum').item()  # sum up batch loss
            pred = output.argmax(dim=1, keepdim=True)  # get the index of the max log-probability
            ddp_loss[1] += pred.eq(target.view_as(pred)).sum().item()
            ddp_loss[2] += len(data)

    dist.all_reduce(ddp_loss, op=dist.ReduceOp.SUM)

    if rank == 0:
        test_loss = ddp_loss[0] / ddp_loss[2]
        print('Test set: Average loss: {:.4f}, Accuracy: {}/{} ({:.2f}%)\n'.format(
            test_loss, int(ddp_loss[1]), int(ddp_loss[2]),
            100. * ddp_loss[1] / ddp_loss[2]))
        
def fsdp_main(rank, world_size, args):
    setup(rank, world_size)

    transform=transforms.Compose([
        transforms.ToTensor(),
        transforms.Normalize((0.1307,), (0.3081,))
    ])

    dataset1 = datasets.MNIST('../data', train=True, download=True,
                        transform=transform)
    dataset2 = datasets.MNIST('../data', train=False,
                        transform=transform)

    sampler1 = DistributedSampler(dataset1, rank=rank, num_replicas=world_size, shuffle=True)
    sampler2 = DistributedSampler(dataset2, rank=rank, num_replicas=world_size)

    train_kwargs = {'batch_size': args.batch_size, 'sampler': sampler1}
    test_kwargs = {'batch_size': args.test_batch_size, 'sampler': sampler2}
    cuda_kwargs = {'num_workers': 2,
                    'pin_memory': True,
                    'shuffle': False}
    train_kwargs.update(cuda_kwargs)
    test_kwargs.update(cuda_kwargs)

    train_loader = torch.utils.data.DataLoader(dataset1,**train_kwargs)
    test_loader = torch.utils.data.DataLoader(dataset2, **test_kwargs)
    my_auto_wrap_policy = functools.partial(
        size_based_auto_wrap_policy, min_num_params=100
    )
    torch.cuda.set_device(rank)


    init_start_event = torch.cuda.Event(enable_timing=True)
    init_end_event = torch.cuda.Event(enable_timing=True)

    
    model = Net()

    
    def apply_with_stopping_condition(module, apply_fn, apply_condition=None, stopping_condition=None, **other_args):
        # if stopping_condition(module):
        #     return
        if apply_condition(module):
            if (torch.cuda.current_device() == 0):
                print(module.children)
            apply_fn(module, **other_args)
            return
        for child in module.children():
            apply_with_stopping_condition(
                child,
                apply_fn,
                apply_condition=apply_condition,
                stopping_condition=stopping_condition,
                **other_args
            )

        
        def apply_fn(m):
            m._fsdp_wrap=True
        
        apply_with_stopping_condition(
            module=model,
            apply_fn=apply_fn,
            apply_condition=lambda m: len(list(m.children())) == 0,
            stopping_condition=lambda m: isinstance(m, FSDP),
        )
        
    model = FSDP(model,
                sharding_strategy=ShardingStrategy.FULL_SHARD,
                auto_wrap_policy=my_auto_wrap_policy,
                device_id=torch.cuda.current_device(),
                use_orig_params=False,
                )
   
    
    a = model.test1.expand(1,-1,-1)
    b = model.attn.q_bias.expand(1,-1,-1)

if __name__ == '__main__':
         WORLD_SIZE=2
    mp.spawn(fsdp_main,
        args=(WORLD_SIZE, args),
        nprocs=WORLD_SIZE,
        join=True)
```

### Versions

PyTorch version: 2.0.0+cu117
Is debug build: False
CUDA used to build PyTorch: 11.7
ROCM used to build PyTorch: N/A

OS: Ubuntu 20.04.3 LTS (x86_64)
GCC version: (Ubuntu 9.4.0-1ubuntu1~20.04.2) 9.4.0
Clang version: Could not collect
CMake version: version 3.27.4
Libc version: glibc-2.31

Python version: 3.8.17 (default, Jul  5 2023, 21:04:15)  [GCC 11.2.0] (64-bit runtime)
Python platform: Linux-5.15.0-58-generic-x86_64-with-glibc2.17
Is CUDA available: True
CUDA runtime version: Could not collect
CUDA_MODULE_LOADING set to: LAZY
GPU models and configuration: 
GPU 0: NVIDIA GeForce RTX 3090
GPU 1: NVIDIA GeForce RTX 3090
GPU 2: NVIDIA GeForce RTX 3090
GPU 3: NVIDIA GeForce RTX 3090
GPU 4: NVIDIA GeForce RTX 3090
GPU 5: NVIDIA GeForce RTX 3090
GPU 6: NVIDIA GeForce RTX 3090
GPU 7: NVIDIA GeForce RTX 3090

Nvidia driver version: 470.82.01
cuDNN version: Could not collect
HIP runtime version: N/A
MIOpen runtime version: N/A
Is XNNPACK available: True

CPU:
Architecture:                    x86_64
CPU op-mode(s):                  32-bit, 64-bit
Byte Order:                      Little Endian
Address sizes:                   46 bits physical, 48 bits virtual
CPU(s):                          104
On-line CPU(s) list:             0-103
Thread(s) per core:              2
Core(s) per socket:              26
Socket(s):                       2
NUMA node(s):                    2
Vendor ID:                       GenuineIntel
CPU family:                      6
Model:                           85
Model name:                      Intel(R) Xeon(R) Gold 6230R CPU @ 2.10GHz
Stepping:                        7
CPU MHz:                         2729.152
CPU max MHz:                     4000.0000
CPU min MHz:                     1000.0000
BogoMIPS:                        4200.00
Virtualization:                  VT-x
L1d cache:                       1.6 MiB
L1i cache:                       1.6 MiB
L2 cache:                        52 MiB
L3 cache:                        71.5 MiB
NUMA node0 CPU(s):               0-25,52-77
NUMA node1 CPU(s):               26-51,78-103
Vulnerability Itlb multihit:     KVM: Mitigation: Split huge pages
Vulnerability L1tf:              Not affected
Vulnerability Mds:               Not affected
Vulnerability Meltdown:          Not affected
Vulnerability Mmio stale data:   Mitigation; Clear CPU buffers; SMT vulnerable
Vulnerability Retbleed:          Mitigation; Enhanced IBRS
Vulnerability Spec store bypass: Mitigation; Speculative Store Bypass disabled via prctl and seccomp
Vulnerability Spectre v1:        Mitigation; usercopy/swapgs barriers and __user pointer sanitization
Vulnerability Spectre v2:        Mitigation; Enhanced IBRS, IBPB conditional, RSB filling, PBRSB-eIBRS SW sequence
Vulnerability Srbds:             Not affected
Vulnerability Tsx async abort:   Mitigation; TSX disabled
Flags:                           fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid dca sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch cpuid_fault epb cat_l3 cdp_l3 invpcid_single intel_ppin ssbd mba ibrs ibpb stibp ibrs_enhanced tpr_shadow vnmi flexpriority ept vpid ept_ad fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid cqm mpx rdt_a avx512f avx512dq rdseed adx smap clflushopt clwb intel_pt avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local dtherm ida arat pln pts pku ospke avx512_vnni md_clear flush_l1d arch_capabilities

Versions of relevant libraries:
[pip3] mypy-extensions==1.0.0
[pip3] numpy==1.24.4
[pip3] torch==2.0.0
[pip3] torchvision==0.15.2
[pip3] triton==2.0.0
[conda] numpy                     1.24.4                   pypi_0    pypi
[conda] torch                     2.0.0                    pypi_0    pypi
[conda] torchvision               0.15.2                   pypi_0    pypi
[conda] triton                    2.0.0                    pypi_0    pypi

cc @mrshenli @pritamdamania87 @zhaojuanmao @satgera @rohan-varma @gqchen @aazzolini @osalpekar @jiayisuse @H-Huang @kwen2501 @awgu @penguinwu @fegin