158 lines
3.6 KiB
Python
Executable file
158 lines
3.6 KiB
Python
Executable file
#!/usr/bin/python
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#
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# pmqos-static.py: Simple daemon for setting static PM QoS values. It is a part
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# of 'tuned' and it should not be called manually.
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#
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# Copyright (C) 2011 Red Hat, Inc.
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# Authors: Jan Vcelak <jvcelak@redhat.com>
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#
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# This program is free software; you can redistribute it and/or
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# modify it under the terms of the GNU General Public License
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# as published by the Free Software Foundation; either version 2
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# of the License, or (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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#
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import os
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import signal
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import struct
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import sys
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import time
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# Used interface is described in Linux kernel documentation:
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# Documentation/power/pm_qos_interface.txt
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ALLOWED_INTERFACES = [ "cpu_dma_latency", "network_latency", "network_throughput" ]
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PIDFILE = "/var/run/tuned/pmqos-static.pid"
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def do_fork():
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pid = os.fork()
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if pid > 0:
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sys.exit(0)
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def close_fds():
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s_in = file('/dev/null', 'r')
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s_out = file('/dev/null', 'a+')
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s_err = file('/dev/null', 'a+', 0)
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os.dup2(s_in.fileno(), sys.stdin.fileno())
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os.dup2(s_out.fileno(), sys.stdout.fileno())
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os.dup2(s_err.fileno(), sys.stderr.fileno())
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def write_pidfile():
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f = os.open(PIDFILE, os.O_CREAT | os.O_TRUNC | os.O_WRONLY, 0644)
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os.write(f, "%d" % os.getpid())
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os.close(f)
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def daemonize():
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do_fork()
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os.chdir("/")
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os.setsid()
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os.umask(0)
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do_fork()
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close_fds()
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def set_pmqos(name, value):
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filename = "/dev/%s" % name
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bin_value = struct.pack("i", int(value))
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fd = os.open(filename, os.O_WRONLY)
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os.write(fd, bin_value)
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return fd
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def sleep_forever():
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while True:
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time.sleep(86400)
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def sigterm_handler(signum, frame):
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global pmqos_fds
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if type(pmqos_fds) is list:
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for fd in pmqos_fds:
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os.close(fd)
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sys.exit(0)
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def run_daemon(options):
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try:
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daemonize()
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write_pidfile()
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signal.signal(signal.SIGTERM, sigterm_handler)
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except Exception, e:
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print >>sys.stderr, "Cannot daemonize (%s)." % e
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return False
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global pmqos_fds
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pmqos_fds = []
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for (name, value) in options.items():
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try:
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new_fd = set_pmqos(name, value)
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pmqos_fds.append(new_fd)
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except:
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# we are daemonized
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pass
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if len(pmqos_fds) > 0:
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sleep_forever()
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else:
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return False
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def kill_daemon(force = False):
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try:
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with open(PIDFILE, "r") as pidfile:
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daemon_pid = int(pidfile.read())
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except IOError, e:
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if not force: print >>sys.stderr, "Cannot open PID file (%s)." % e
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return False
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try:
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os.kill(daemon_pid, signal.SIGTERM)
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except OSError, e:
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if not force: print >>sys.stderr, "Cannot terminate the daemon (%s)." % e
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return False
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try:
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os.unlink(PIDFILE)
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except OSError, e:
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if not force: print >>sys.stderr, "Cannot delete the PID file (%s)." % e
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return False
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return True
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if __name__ == "__main__":
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disable = False
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options = {}
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for option in sys.argv[1:]:
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if option == "disable":
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disable = True
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break
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try:
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(name, value) = option.split("=")
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except ValueError:
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name = option
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value = None
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if name in ALLOWED_INTERFACES and len(value) > 0:
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options[name] = value
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else:
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print >>sys.stderr, "Invalid option (%s)." % option
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if disable:
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sys.exit(0 if kill_daemon() else 1)
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if len(options) == 0:
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print >>sys.stderr, "No options set. Not starting."
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sys.exit(1)
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kill_daemon(True)
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run_daemon(options)
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sys.exit(1)
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