Files
dmlc--dgl/examples/pytorch/multigpu/multi_gpu_link_prediction.py
2026-07-13 13:35:51 +08:00

317 lines
11 KiB
Python

import argparse
import os
import time
import dgl.function as fn
import dgl.nn as dglnn
import numpy as np
import sklearn.linear_model as lm
import sklearn.metrics as skm
import torch
import torch.distributed as dist
import torch.multiprocessing as mp
import torch.nn as nn
import torch.nn.functional as F
import tqdm
from dgl.data import AsNodePredDataset, RedditDataset
from dgl.dataloading import (
as_edge_prediction_sampler,
DataLoader,
MultiLayerFullNeighborSampler,
NeighborSampler,
)
from dgl.multiprocessing import shared_tensor
from ogb.nodeproppred import DglNodePropPredDataset
from torch.nn.parallel import DistributedDataParallel
class SAGE(nn.Module):
def __init__(self, in_size, hid_size, out_size):
super().__init__()
self.layers = nn.ModuleList()
# two-layer GraphSAGE-mean
self.layers.append(dglnn.SAGEConv(in_size, hid_size, "mean"))
self.layers.append(dglnn.SAGEConv(hid_size, out_size, "mean"))
self.dropout = nn.Dropout(0.5)
self.hid_size = hid_size
self.out_size = out_size
def forward(self, blocks, x):
h = x
for l, (layer, block) in enumerate(zip(self.layers, blocks)):
h = layer(block, h)
if l != len(self.layers) - 1:
h = F.relu(h)
h = self.dropout(h)
return h
def inference(self, g, device, batch_size, use_uva):
g.ndata["h"] = g.ndata["feat"]
sampler = MultiLayerFullNeighborSampler(1, prefetch_node_feats=["h"])
for l, layer in enumerate(self.layers):
dataloader = DataLoader(
g,
torch.arange(g.num_nodes(), device=device),
sampler,
device=device,
batch_size=batch_size,
shuffle=False,
drop_last=False,
num_workers=0,
use_ddp=True,
use_uva=use_uva,
)
# in order to prevent running out of GPU memory, allocate a
# shared output tensor 'y' in host memory
y = shared_tensor(
(
g.num_nodes(),
self.hid_size
if l != len(self.layers) - 1
else self.out_size,
)
)
for input_nodes, output_nodes, blocks in (
tqdm.tqdm(dataloader) if dist.get_rank() == 0 else dataloader
):
x = blocks[0].srcdata["h"]
h = layer(blocks[0], x) # len(blocks) = 1
if l != len(self.layers) - 1:
h = F.relu(h)
h = self.dropout(h)
# non_blocking (with pinned memory) to accelerate data transfer
y[output_nodes] = h.to(y.device, non_blocking=True)
# make sure all GPUs are done writing to 'y'
dist.barrier()
g.ndata["h"] = y if use_uva else y.to(device)
g.ndata.pop("h")
return y
class NegativeSampler(object):
def __init__(self, g, k, neg_share=False, device=None):
if device is None:
device = g.device
self.weights = g.in_degrees().float().to(device) ** 0.75
self.k = k
self.neg_share = neg_share
def __call__(self, g, eids):
src, _ = g.find_edges(eids)
n = len(src)
if self.neg_share and n % self.k == 0:
dst = self.weights.multinomial(n, replacement=True)
dst = dst.view(-1, 1, self.k).expand(-1, self.k, -1).flatten()
else:
dst = self.weights.multinomial(n * self.k, replacement=True)
src = src.repeat_interleave(self.k)
return src, dst
class CrossEntropyLoss(nn.Module):
def forward(self, block_outputs, pos_graph, neg_graph):
with pos_graph.local_scope():
pos_graph.ndata["h"] = block_outputs
pos_graph.apply_edges(fn.u_dot_v("h", "h", "score"))
pos_score = pos_graph.edata["score"]
with neg_graph.local_scope():
neg_graph.ndata["h"] = block_outputs
neg_graph.apply_edges(fn.u_dot_v("h", "h", "score"))
neg_score = neg_graph.edata["score"]
score = torch.cat([pos_score, neg_score])
label = torch.cat(
[torch.ones_like(pos_score), torch.zeros_like(neg_score)]
).long()
loss = F.binary_cross_entropy_with_logits(score, label.float())
return loss
def compute_acc_unsupervised(emb, labels, train_nids, val_nids, test_nids):
"""
Compute the accuracy of prediction given the labels.
"""
emb = emb.cpu().numpy()
labels = labels.cpu().numpy()
train_nids = train_nids.cpu().numpy()
train_labels = labels[train_nids]
val_nids = val_nids.cpu().numpy()
val_labels = labels[val_nids]
test_nids = test_nids.cpu().numpy()
test_labels = labels[test_nids]
emb = (emb - emb.mean(0, keepdims=True)) / emb.std(0, keepdims=True)
lr = lm.LogisticRegression(multi_class="multinomial", max_iter=10000)
lr.fit(emb[train_nids], train_labels)
pred = lr.predict(emb)
f1_micro_eval = skm.f1_score(val_labels, pred[val_nids], average="micro")
f1_micro_test = skm.f1_score(test_labels, pred[test_nids], average="micro")
return f1_micro_eval, f1_micro_test
def evaluate(proc_id, model, g, device, use_uva):
model.eval()
batch_size = 10000
with torch.no_grad():
pred = model.module.inference(g, device, batch_size, use_uva)
return pred
def train(
proc_id, nprocs, device, g, train_idx, val_idx, test_idx, model, use_uva
):
# Create PyTorch DataLoader for constructing blocks
n_edges = g.num_edges()
train_seeds = torch.arange(n_edges).to(device)
labels = g.ndata["label"].to("cpu")
sampler = NeighborSampler([10, 25], prefetch_node_feats=["feat"])
sampler = as_edge_prediction_sampler(
sampler,
exclude="reverse_id",
# For each edge with ID e in Reddit dataset, the reverse edge is e ± |E|/2.
reverse_eids=torch.cat(
[torch.arange(n_edges // 2, n_edges), torch.arange(0, n_edges // 2)]
).to(train_seeds),
# num_negs = 1, neg_share = False
negative_sampler=NegativeSampler(
g, 1, False, device if use_uva else None
),
)
train_dataloader = DataLoader(
g,
train_seeds,
sampler,
device=device,
batch_size=10000,
shuffle=True,
drop_last=False,
num_workers=0,
use_ddp=True,
use_uva=use_uva,
)
opt = torch.optim.Adam(model.parameters(), lr=0.003)
loss_fcn = CrossEntropyLoss()
iter_pos = []
iter_neg = []
for epoch in range(10):
tic = time.time()
model.train()
for step, (input_nodes, pos_graph, neg_graph, blocks) in enumerate(
train_dataloader
):
x = blocks[0].srcdata["feat"]
y_hat = model(blocks, x)
loss = loss_fcn(y_hat, pos_graph, neg_graph)
opt.zero_grad()
loss.backward()
opt.step()
if step % 20 == 0 and proc_id == 0: # log every 20 steps
# gpu memory reserved by PyTorch
gpu_mem_alloc = (
torch.cuda.max_memory_allocated() / 1000000
if torch.cuda.is_available()
else 0
)
print(
f"Epoch {epoch:05d} | Step {step:05d} | Loss {loss.item():.4f} | GPU {gpu_mem_alloc:.1f} MB"
)
t = time.time() - tic
if proc_id == 0:
print(f"Epoch Time(s): {t:.4f}")
if (epoch + 1) % 5 == 0: # eval every 5 epochs
pred = evaluate(proc_id, model, g, device, use_uva) # in parallel
if proc_id == 0:
# only master proc does the accuracy computation
eval_acc, test_acc = compute_acc_unsupervised(
pred, labels, train_idx, val_idx, test_idx
)
print(
f"Epoch {epoch:05d} | Eval F1-score {eval_acc:.4f} | Test F1-Score {test_acc:.4f}"
)
def run(proc_id, nprocs, devices, g, data, mode):
# find corresponding device for my rank
device = devices[proc_id]
torch.cuda.set_device(device)
# initialize process group and unpack data for sub-processes
dist.init_process_group(
backend="nccl",
init_method="tcp://127.0.0.1:12345",
world_size=nprocs,
rank=proc_id,
)
out_size, train_idx, val_idx, test_idx = data
g = g.to(device if mode == "puregpu" else "cpu")
# create GraphSAGE model (distributed)
in_size = g.ndata["feat"].shape[1]
model = SAGE(in_size, 16, 16).to(device)
model = DistributedDataParallel(
model, device_ids=[device], output_device=device
)
# training + testing
use_uva = mode == "mixed"
train(
proc_id, nprocs, device, g, train_idx, val_idx, test_idx, model, use_uva
)
# cleanup process group
dist.destroy_process_group()
if __name__ == "__main__":
parser = argparse.ArgumentParser()
parser.add_argument(
"--dataset",
type=str,
default="ogbn-products",
choices=["ogbn-products", "reddit"],
help="name of dataset (default: ogbn-products)",
)
parser.add_argument(
"--mode",
default="mixed",
choices=["mixed", "puregpu"],
help="Training mode. 'mixed' for CPU-GPU mixed training, "
"'puregpu' for pure-GPU training.",
)
parser.add_argument(
"--gpu",
type=str,
default="0",
help="GPU(s) in use. Can be a list of gpu ids for multi-gpu training,"
" e.g., 0,1,2,3.",
)
args = parser.parse_args()
devices = list(map(int, args.gpu.split(",")))
nprocs = len(devices)
assert (
torch.cuda.is_available()
), f"Must have GPUs to enable multi-gpu training."
print(f"Training in {args.mode} mode using {nprocs} GPU(s)")
# load and preprocess dataset
print("Loading data")
if args.dataset == "ogbn-products":
# can it be AsLinkPredDataset?
dataset = AsNodePredDataset(DglNodePropPredDataset("ogbn-products"))
elif args.dataset == "reddit":
dataset = AsNodePredDataset(RedditDataset(self_loop=False))
g = dataset[0]
# avoid creating certain graph formats in each sub-process to save momory
g.create_formats_()
# thread limiting to avoid resource competition
os.environ["OMP_NUM_THREADS"] = str(mp.cpu_count() // 2 // nprocs)
data = (
dataset.num_classes,
dataset.train_idx,
dataset.val_idx,
dataset.test_idx,
)
mp.spawn(run, args=(nprocs, devices, g, data, args.mode), nprocs=nprocs)