[dpdk-dev] [PATCH v4] usertools: add huge page setup script

Stephen Hemminger stephen at networkplumber.org
Sat Sep 5 05:07:21 CEST 2020


This is an improved version of the setup of huge pages
bases on earlier DPDK setup. Differences are:
   * it autodetects NUMA vs non NUMA
   * it allows setting different page sizes
     recent kernels support multiple sizes.
   * it accepts a parameter in bytes (not pages).

If necessary the steps of clearing old settings and mounting/umounting
can be done individually.

Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
---
v4 -- more review feedback
      use argparser rather than getopt (thanks Bruce)
      silently handle already mounted type errors
      handle exceptions for permission and file not found
      fix numa bugs
      code now passes pylint

v3 -- incorporate review feedback
      add missing SPDX and env header
      overengineer the memory prefix string code
      add numa node argument
      fix some pylint warnings

v2 -- convert to python3

 usertools/hugepage_setup.py | 272 ++++++++++++++++++++++++++++++++++++
 1 file changed, 272 insertions(+)
 create mode 100755 usertools/hugepage_setup.py

diff --git a/usertools/hugepage_setup.py b/usertools/hugepage_setup.py
new file mode 100755
index 000000000000..3091dbe5d4c2
--- /dev/null
+++ b/usertools/hugepage_setup.py
@@ -0,0 +1,272 @@
+#! /usr/bin/env python3
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (c) 2020 Microsoft Corporation
+"""Script to query and setup huge pages for DPDK applications."""
+
+import argparse
+import glob
+import os
+import re
+import sys
+from math import log2
+
+# Standard binary prefix
+BINARY_PREFIX = "KMG"
+
+# systemd mount point for huge pages
+HUGE_MOUNT = "/dev/hugepages"
+
+
+def fmt_memsize(sz_k):
+    '''Format memory size in kB into conventional format'''
+    if sz_k.isdigit():
+        return int(sz_k) / 1024
+    logk = int(log2(sz_k) / 10)
+    return '{}{}b'.format(int(sz_k / (2**(logk * 10))), BINARY_PREFIX[logk])
+
+
+def get_memsize(arg):
+    '''Convert memory size with suffix to kB'''
+    match = re.match(r'(\d+)([' + BINARY_PREFIX + r']?)$', arg.upper())
+    if match is None:
+        sys.exit('{} is not a valid page size'.format(arg))
+    num = float(match.group(1))
+    suffix = match.group(2)
+    if suffix == "":
+        return int(num / 1024)
+    idx = BINARY_PREFIX.find(suffix)
+    return int(num * (2**(idx * 10)))
+
+
+def is_numa():
+    '''Test if NUMA is necessary on this system'''
+    return os.path.exists('/sys/devices/system/node')
+
+
+def get_hugepages(path):
+    '''Read number of reserved pages'''
+    with open(path + '/nr_hugepages') as nr_hugpages:
+        return int(nr_hugpages.read())
+    return 0
+
+
+def set_hugepages(path, pages):
+    '''Write the number of reserved huge pages'''
+    filename = path + '/nr_hugepages'
+    try:
+        with open(filename, 'w') as nr_hugpages:
+            nr_hugpages.write('{}\n'.format(pages))
+    except PermissionError:
+        sys.exit('Permission denied: need to be root!')
+    except FileNotFoundError:
+        filename = os.path.basename(path)
+        size = filename[10:]
+        sys.exit('{} is not a valid system huge page size'.format(size))
+
+
+def show_numa_pages():
+    '''Show huge page reservations on Numa system'''
+    print('Node Pages Size')
+    for numa_path in glob.glob('/sys/devices/system/node/node*'):
+        node = numa_path[29:]  # slice after /sys/devices/system/node/node
+        path = numa_path + '/hugepages'
+        for hdir in os.listdir(path):
+            pages = get_hugepages(path + '/' + hdir)
+            if pages > 0:
+                pg_sz = fmt_memsize(
+                    hdir[10:-2])  # slice out of hugepages-NNNkB
+                print('{:<4} {:<5} {}'.format(node, pages, pg_sz))
+
+
+def show_non_numa_pages():
+    '''Show huge page reservations on non Numa system'''
+    print('Pages Size')
+    path = '/sys/kernel/mm/hugepages'
+    for hdir in os.listdir(path):
+        pages = get_hugepages(path + '/' + hdir)
+        if pages > 0:
+            pg_sz = fmt_memsize(int(hdir[10:-2]))
+            print('{:<5} {}'.format(pages, pg_sz))
+
+
+def show_pages():
+    '''Show existing huge page settings'''
+    if is_numa():
+        show_numa_pages()
+    else:
+        show_non_numa_pages()
+
+
+def clear_pages():
+    '''Clear all existing huge page mappings'''
+    if is_numa():
+        dirs = glob.glob(
+            '/sys/devices/system/node/node*/hugepages/hugepages-*')
+    else:
+        dirs = glob.glob('/sys/kernel/mm/hugepages/hugepages-*')
+
+    for path in dirs:
+        set_hugepages(path, 0)
+
+
+def default_pagesize():
+    '''Get default huge page size from /proc/meminfo'''
+    with open('/proc/meminfo') as meminfo:
+        for line in meminfo:
+            if line.startswith('Hugepagesize:'):
+                return int(line.split()[1])
+    return None
+
+
+def set_numa_pages(pages, hugepgsz, node=None):
+    '''Set huge page reservation on Numa system'''
+    if node:
+        nodes = ['/sys/devices/system/node/node{}/hugepages'.format(node)]
+    else:
+        nodes = glob.glob('/sys/devices/system/node/node*/hugepages')
+
+    for node_path in nodes:
+        huge_path = '{}/hugepages-{}kB'.format(node_path, hugepgsz)
+        set_hugepages(huge_path, pages)
+
+
+def set_non_numa_pages(pages, hugepgsz):
+    '''Set huge page reservation on non Numa system'''
+    path = '/sys/kernel/mm/hugepages/hugepages-{}kB'.format(hugepgsz)
+    set_hugepages(path, pages)
+
+
+def reserve_pages(pages, hugepgsz, node=None):
+    '''Sets the number of huge pages to be reserved'''
+    if node or is_numa():
+        set_numa_pages(pages, hugepgsz, node=node)
+    else:
+        set_non_numa_pages(pages, hugepgsz)
+
+
+def get_mountpoints():
+    '''get list of of where hugepage filesystem is mounted'''
+    mounted = []
+    with open('/proc/mounts') as mounts:
+        for line in mounts:
+            fields = line.split()
+            if fields[2] != 'hugetlbfs':
+                continue
+            mounted.append(fields[1])
+    return mounted
+
+
+def mount_huge(pagesize, mountpoint):
+    '''mount the huge tlb file system'''
+    if mountpoint in get_mountpoints():
+        print(mountpoint, "already mounted")
+        return
+    cmd = "mount -t hugetlbfs"
+    if pagesize:
+        cmd += ' -o pagesize={}'.format(pagesize * 1024)
+    cmd += ' nodev ' + mountpoint
+    os.system(cmd)
+
+
+def umount_huge(mountpoint):
+    '''unmount the huge tlb file system (if mounted)'''
+    if mountpoint in get_mountpoints():
+        os.system("umount " + mountpoint)
+
+
+def show_mount():
+    '''Show where huge page filesystem is mounted'''
+    mounted = get_mountpoints()
+    if mounted:
+        print("Hugepages mounted on", *mounted)
+    else:
+        print("Hugepages not mounted")
+
+
+def main():
+    '''Process the command line arguments and setup huge pages'''
+    argv0 = os.path.basename(sys.argv[0])
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        description="Setup huge pages",
+        epilog="""
+Examples:
+
+To display current huge page settings:
+    {argv0} -s
+
+To a complete setup of with 2 Gigabyte of 1G huge pages:
+    {argv0} -p 1G --setup 2G
+""".format(argv0=argv0))
+    parser.add_argument(
+        '--show',
+        '-s',
+        action='store_true',
+        help="print the current huge page configuration")
+    parser.add_argument(
+        '--clear', '-c', action='store_true', help="clear existing huge pages")
+    parser.add_argument(
+        '--mount',
+        '-m',
+        action='store_true',
+        help='mount the huge page filesystem')
+    parser.add_argument(
+        '--unmount',
+        '-u',
+        action='store_true',
+        help='unmount the system huge page directory')
+    parser.add_argument(
+        '--node',
+        '-n',
+        action='store',
+        help='select numa node to reserve pages on')
+    parser.add_argument(
+        '--pagesize',
+        '-p',
+        action='store',
+        help='choose huge page size to use')
+    parser.add_argument(
+        '--reserve',
+        '-r',
+        action='store',
+        help='reserve huge pages. Size is in bytes with K, M, or G suffix')
+    parser.add_argument(
+        '--setup',
+        action='store',
+        help='setup huge pages by doing clear, unmount, reserve and mount')
+    args = parser.parse_args()
+
+    if args.setup:
+        args.clear = True
+        args.unmount = True
+        args.reserve = args.setup
+        args.mount = True
+
+    if args.pagesize:
+        pagesize_kb = get_memsize(args.pagesize)
+    else:
+        pagesize_kb = default_pagesize()
+
+    if args.clear:
+        clear_pages()
+    if args.unmount:
+        umount_huge(HUGE_MOUNT)
+
+    if args.reserve:
+        reserve_kb = get_memsize(args.reserve)
+        if reserve_kb % pagesize_kb != 0:
+            sys.exit(
+                'Huge reservation {}kB is not a multiple of page size {}kB'.
+                format(reserve_kb, pagesize_kb))
+        reserve_pages(
+            int(reserve_kb / pagesize_kb), pagesize_kb, node=args.node)
+    if args.mount:
+        mount_huge(pagesize_kb, HUGE_MOUNT)
+    if args.show:
+        show_pages()
+        print()
+        show_mount()
+
+
+if __name__ == "__main__":
+    main()
-- 
2.27.0



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