Author: tack
Date: Tue May 8 23:56:55 2007
New Revision: 2674
Modified:
trunk/beacon/src/server/cpuinfo.py
Log:
Start cpu monitor timer on demand, rather than leave it always
running. (Prevents needless wakeups every second that reads /proc
for info we never use.) Also cleaned up some of the logic a bit.
Hopefully I didn't break it. :)
Modified: trunk/beacon/src/server/cpuinfo.py
==============================================================================
--- trunk/beacon/src/server/cpuinfo.py (original)
+++ trunk/beacon/src/server/cpuinfo.py Tue May 8 23:56:55 2007
@@ -34,13 +34,14 @@
# python imports
import os
+import time
# kaa imports
import kaa.notifier
_stat = None, None
_proc = None, None
-_counter = 0
+_last_request_time = None
_cache = None
USER = 0
@@ -56,43 +57,45 @@
"""
poll /proc files and remeber lines we need later.
"""
- global _stat
- global _proc
- global _counter
- global _cache
- fp = open('/proc/stat')
- _stat = fp.readline(), _stat[0]
- fp.close()
- fp = open('/proc/%s/stat' % pid)
- _proc = fp.readline(), _proc[0], _timer.get_interval()
- fp.close()
+ global _stat, _proc, _cache
+ _stat = file('/proc/stat').readline(), _stat[0]
+ _proc = file('/proc/%s/stat' % pid).readline(), _proc[0],
_timer.get_interval()
_cache = None
- if _counter == 0:
+ if not _last_request_time:
return True
- _counter -= 1
- if _counter > 0:
- return True
- # no access for 5 seconds, slow down
- _timer.stop()
- _timer.start(1)
+
+ delta = time.time() - _last_request_time
+ if _timer.get_interval() < 1 and delta > 3:
+ # CPU time hasn't been requested in the past 3 seconds, so slow
+ # timer down.
+ _timer.stop()
+ _timer.start(1)
+ elif _timer.get_interval() == 1 and delta > 10:
+ # CPU time hasn't been requested in the past 10 seconds. Disable
+ # polling.
+ return False
-# when this module is imported, use it. The first valid
-# information will be ready in 1 second
+# Timer that polls cpu stats. Started on demand.
_timer = kaa.notifier.Timer(_poll, os.getpid())
-_timer.start(1)
-_poll(os.getpid())
-_poll(os.getpid())
def cpuinfo():
"""
Returns /proc/stat values and the cpu time the current process
is using the last second.
"""
- global _cache
+ global _cache, _last_request_time
if _cache:
# nothing changed
return _cache
+ elif not _timer.active():
+ # First call to cpuinfo() (either ever or since poll timer got
+ # stopped), so take initial measurements and start timer now.
+ _last_request_time = time.time()
+ _timer.start(1)
+ _poll(os.getpid())
+ _poll(os.getpid())
+
# user: normal processes executing in user mode
# nice: niced processes executing in user mode
# system: processes executing in kernel mode
@@ -101,7 +104,7 @@
# irq: servicing interrupts
# softirq: servicing softirqs
if not _stat or _stat[0] == _stat[1]:
- return 0, 0, 0, 100, 0, 0, 0, 0
+ return 0, 0, 0, 100, 0, 0, 0, 0, 0
info = [ i for i in _stat[0].strip().split(' ') if i ]
last = [ i for i in _stat[1].strip().split(' ') if i ]
all = 0
@@ -119,15 +122,15 @@
# wrong. So a C wrapper is needed here I guess.
res.append(int((info - last) / _proc[2]))
- global _counter
- if _counter == 0:
- # speed up polling
+ if time.time() - _last_request_time < 2 and _timer.get_interval() != 0.2:
+ # CPU time is being requested a lot, so increase poll timer frequency
+ # to get a more accurate reading.
_timer.stop()
- _timer.start(0.1)
- # poll now and in 0.1 seconds again. We set the _cache after
+ _timer.start(0.2)
+ # poll now and in 0.2 seconds again. We set the _cache after
# calling _poll to not mess it up
_poll(os.getpid())
- _counter = 50
+ _last_request_time = time.time()
_cache = res
return res
@@ -135,16 +138,18 @@
if __name__ == '__main__':
def debug():
- print cpuinfo()
+ print "CPU:", cpuinfo()
+ @kaa.notifier.yield_execution()
def add_load():
x = 0
- for i in range(10000):
- x += i
+ for i in range(300000):
+ yield kaa.notifier.YieldContinue
+ print "Done load generation"
- kaa.notifier.Timer(add_load).start(0.001)
+ add_load()
t = kaa.notifier.Timer(debug)
t.start(1)
- kaa.notifier.OneShotTimer(t.stop).start(6)
- kaa.notifier.OneShotTimer(t.start, 1).start(15)
+ kaa.notifier.OneShotTimer(t.stop).start(4)
+ kaa.notifier.OneShotTimer(t.start, 1).start(10)
kaa.main()
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