#
# Copyright (C) 2017 Intel Corporation.
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from cmd_helper import CMD_helper
import os
import itertools
"""
Huge_page_organizer sets hugepages per NUMA node and restores initial setup of hugepages.
It writes and reads from the same file, so using Huge_page_organizer with parallel
execution may cause undefined behaviour.
"""
class Huge_page_organizer(object):
cmd_helper = CMD_helper()
path = "/sys/devices/system/node/node{0}/hugepages/hugepages-2048kB/nr_hugepages"
restore_values = []
def __restore(self):
"""Restore initial setup of hugepages."""
for node_id, restore_value in enumerate(self.restore_values):
self.__set_nr_hugepages(node_id, restore_value)
def __get_nr_hugepages(self, node_id):
"""Return number of hugepages on given node or None if given node is not configured."""
if not os.path.isfile(self.path.format(node_id)):
return None
with open(self.path.format(node_id), "r") as f:
return int(f.read())
def __set_nr_hugepages(self, node_id, nr_hugepages):
"""Set hugepages on given node to given number. Return True on success, False otherwise."""
command = 'sh -c "echo {0} >> {1}"'.format(nr_hugepages, self.path.format(node_id))
output, retcode = self.cmd_helper.execute_cmd(command, sudo=True)
if retcode:
return False
return self.__get_nr_hugepages(node_id) is nr_hugepages
def __init__(self, nr_hugepages_per_node):
"""Save current hugepages setup and set hugepages per NUMA node."""
for node_id in itertools.count():
nr_hugepages = self.__get_nr_hugepages(node_id)
if nr_hugepages is None:
break
self.restore_values.append(nr_hugepages)
retcode = self.__set_nr_hugepages(node_id, nr_hugepages_per_node)
if not retcode:
self.__restore()
assert retcode, "Error: Could not set the requested amount of hugepages."
def __del__(self):
"""Call __restore() function."""
self.__restore()