hunting down the memory lost when loading coverages

load_memory.py

import gevent
import gc
from load_datasets import *

def get_mem():
    import resource
    return resource.getrusage(resource.RUSAGE_SELF).ru_maxrss / (1024.0**2)
    
data_product_id, stream_id, route, stream_def_id, dataset_id = create_data_product('ctd_parsed_param_dict')
populate_data_product(data_product_id,1)

for x in xrange(10):
    s = get_mem()
    cov = pn.dataset_management._get_coverage(dataset_id)
    e = get_mem()
    print e-s, 'mb'
    cov.close()
    gevent.sleep(0.2)

print ''
from coverage_model import AbstractCoverage
root = '/tmp/ion/run/cache/datasets/'
for x in xrange(10):
    s = get_mem()
    cov = AbstractCoverage.load(root, dataset_id, mode='r')
    e = get_mem()
    print e-s, 'mb'
    cov.close()
    gevent.sleep(0.2)