GPU memory leak when runing multiplication

[zb12138]

GPU memory leak when runing *sp1sp2**

import MinkowskiEngine as ME 
import numpy as np

import os
import psutil
import pynvml
pynvml.nvmlInit()
gpu_id=0
handler = pynvml.nvmlDeviceGetHandleByIndex(gpu_id)

device = 'cuda:0'  
coords = np.random.randint(0, 100, size=(10000, 3))
colors = np.random.randint(0, 255, size=(10000, 1))

feats = np.ones((colors.shape[0],1))
coords_batch, feats_batch = ME.utils.sparse_collate([coords], [feats])
spw = ME.SparseTensor(features=feats_batch.float(), coordinates=coords_batch,device=device,requires_grad=False) 

feats = colors 
coords_batch, feats_batch = ME.utils.sparse_collate([coords], [feats])
spc = ME.SparseTensor(features=feats_batch.float(), coordinates=coords_batch, coordinate_manager=spw.coordinate_manager,device=device)

for i in range(100000000):
    s = spc*spw
    if i%1000==0:
        meminfo = pynvml.nvmlDeviceGetMemoryInfo(handler)
        used = round(meminfo.used / 1024 / 1024, 2)
        print(i,'GPU Mem used', used, 'MB')