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Hi list,

First Hello to all, I have a serious problem for understand some results when I'm comparing cpu usages between same python code in embedded mode and standalone mode ( python name_script.py )

This
last months I have been writing a program in c like to mod_python for
embedding python language, it's a middleware for dispatch and execute
python batch programs into several nodes. Now I'm writing some python
program for test how scale this into several nodes and comparing with
"standalone" performance.

I found a very strange problem with one application named
md5challenge, this aplication try to calculate the max number md5
digest in several seconds, md5challenge use a simple signal alarm for
stop program when time has passed. This is the code of python script

_nrdigest = 0
_const_b = 20
_f = None
_signal = False

def handler_alrm(signum, frame):
    global _signal

    global _nrdigest
    global _f

    _signal = True

def try_me():
    global _nrdigest
    global _f
    global _signal

    _f = open("/dev/urandom","r")
    while _signal is not True:

        buff = _f.read(_const_b)
        md5.md5(buff).hexdigest()
        _nrdigest = _nrdigest + 1

    if _f is not None :
        _f.close()

# Define entry point with one input variable

# req is a instance of Request object, usefull members of this object are:

# req.input is a dictionary with input.xml variables
# req.constants is a dictionary with constants defined into signature.xml
# req.output is void dictionary for full with output variables
# req.config is a dictionary with config values take from namespace

# req.apdn_pid is a pid of aplication

def main( req ):
    global _nrdigest

    signal.signal(signal.SIGALRM, handler_alrm)
    signal.alarm(req.input['time'])

    try_me()

    req.output['count'] = _nrdigest

    return req.OK

if __name__ == "__main__":

    # test code
    class test_req:
        pass

    req = test_req()

    req.input = { 'time' : 10 }
    req.output = { 'ret' : 0, 'count' : 0 }
    req.OK = 1

    main(req)

    print "Reached %d digests" % req.output['count']

When I try to run this program in standalone into my Pentium Dual Core md5challenge reached 1.000.000 milion keys in 10 seconds but when i try to run this code in embedded mode md5challenge reached about 200.000 more keys !!! I repeat this test many times and always wins embedded mode !!! What's happen ?

Also I tested to erase read dependencies from /dev/random, and calculate all keys from same buffer. In this case embedded mode win always also, and the difference are more bigger !!!

The alarm time expires in both case in 10 seconds.

Thks to all, can anybody help to me for understand this results ?

--
Pau Freixes
Linux GNU/User