a.py

import torch
import json

N = 2 ** 28

glist = []
mempool = torch.cuda.graph_pool_handle()
for _ in range(3):
    g = torch.cuda.CUDAGraph()
    glist.append(g)
    with torch.cuda.graph(g, pool=mempool):
        x = torch.randn(N, device="cuda")
        del x
        
    print(g.pool())

print(json.dumps(torch.cuda.memory_snapshot(), indent=2))