Code snippets to help memory management in Google Colab.
GPU¶
Use !nvidia-smi
to get GPU details and current memory usage.
torch.cuda.empty_cache()
clears GPU cache to free up GPU memory
CPU RAM¶
def show_ram_usage():
import psutil
"Check overall RAM usage"
pu_mem = psutil.Process(os.getpid())
print('RAM usage: {} GB'.format(pu_mem_,memory_info([0]/1024 ** 3)))
def purge_mem(vars=None, mem=True):
"Delete `vars` and recycle CPU memory. Show new RAM if `mem=True`"
for var in vars:
del var
gc.collect()
if mem: show_ram_usage()
Dataframe memory usage¶
def show_df_mem_usage(df):
"Check dataframe `df` memory use"
print('Shape: ', df.shape)
print('Total Mem usage: ', df.memory_usage().sum())
df.memory_usage()
def reduce_df_mem_usage(df, verbose=True):
"Reduce size of dataframe `df` columns to minimise memory usage"
numerics = ['int16', 'int32', 'int64', 'float64']
start_mem = df.memory_usage().sum() / 1024**2
for col in df.columns:
col_type = df[col].dtypes
if col_type in numerics:
c_min = df[col].min()
c_max = df[col].max()
if str(col_type)[:3] == 'int':
if c_min > np.iinfo(np.int8).min and c_max < np.iinfo(np.int8).max:
df[col] = df[col].astype(np.int8)
elif c_min > np.iinfo(np.int16).min and c_max < np.iinfo(np.int16).max:
df[col] = df[col].astype(np.int16)
elif c_min > np.iinfo(np.int32).min and c_max < np.iinfo(np.int32).max:
df[col] = df[col].astype(np.int32)
elif c_min > np.iinfo(np.int64).min and c_max < np.iinfo(np.int64).max:
df[col] = df[col].astype(np.int64)
else:
if c_min > np.finfo(np.float16).min and c_max < np.finfo(np.float16).max:
df[col] = df[col].astype(np.float16)
elif c_min > np.finfo(np.float32).min and c_max < np.finfo(np.float32).max:
df[col] = df[col].astype(np.float32)
else:
df[col] = df[col].astype(np.float64)
end_mem = df.memory_usage().sum() / 1024**2
if verbose: print('Mem. usage decreased to {:5.2f} Mb ({:.1f}% reduction)'.format(end_mem, 100 * (start_mem - end_mem) / start_mem))
return df