charm-swift-storage/charmhelpers/core/hugepage.py
James Page 264b0885e8 Resync charmhelpers for licensing change
The charm-helpers project have re-licensed to Apache 2.0
inline with the agreed licensing approach to intefaces,
layers and charms generally.

Resync helpers to bring charmhelpers inline with charm
codebase.

Change-Id: I99e94eec42adc19ab92b14a20e59cc60360e0b58
2016-07-06 16:44:39 +01:00

70 lines
2.6 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2014-2015 Canonical Limited.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import yaml
from charmhelpers.core import fstab
from charmhelpers.core import sysctl
from charmhelpers.core.host import (
add_group,
add_user_to_group,
fstab_mount,
mkdir,
)
from charmhelpers.core.strutils import bytes_from_string
from subprocess import check_output
def hugepage_support(user, group='hugetlb', nr_hugepages=256,
max_map_count=65536, mnt_point='/run/hugepages/kvm',
pagesize='2MB', mount=True, set_shmmax=False):
"""Enable hugepages on system.
Args:
user (str) -- Username to allow access to hugepages to
group (str) -- Group name to own hugepages
nr_hugepages (int) -- Number of pages to reserve
max_map_count (int) -- Number of Virtual Memory Areas a process can own
mnt_point (str) -- Directory to mount hugepages on
pagesize (str) -- Size of hugepages
mount (bool) -- Whether to Mount hugepages
"""
group_info = add_group(group)
gid = group_info.gr_gid
add_user_to_group(user, group)
if max_map_count < 2 * nr_hugepages:
max_map_count = 2 * nr_hugepages
sysctl_settings = {
'vm.nr_hugepages': nr_hugepages,
'vm.max_map_count': max_map_count,
'vm.hugetlb_shm_group': gid,
}
if set_shmmax:
shmmax_current = int(check_output(['sysctl', '-n', 'kernel.shmmax']))
shmmax_minsize = bytes_from_string(pagesize) * nr_hugepages
if shmmax_minsize > shmmax_current:
sysctl_settings['kernel.shmmax'] = shmmax_minsize
sysctl.create(yaml.dump(sysctl_settings), '/etc/sysctl.d/10-hugepage.conf')
mkdir(mnt_point, owner='root', group='root', perms=0o755, force=False)
lfstab = fstab.Fstab()
fstab_entry = lfstab.get_entry_by_attr('mountpoint', mnt_point)
if fstab_entry:
lfstab.remove_entry(fstab_entry)
entry = lfstab.Entry('nodev', mnt_point, 'hugetlbfs',
'mode=1770,gid={},pagesize={}'.format(gid, pagesize), 0, 0)
lfstab.add_entry(entry)
if mount:
fstab_mount(mnt_point)