multiprocessing timestamp takes a lot of time












-1














I created a program that spawn processes and run the provided algorithm. When I run the algorithm without multiprocessing it takes 1.7 sec, but when I spawn two processes that run the same algorithm it takes 18 sec.



Profiler result for one process without spawning:
68050 0.084 0.000 0.084 0.000 {method 'timestamp' of 'datetime.datetime' objects}



With spawning two processes for one of spawned processes:
34025 15.947 0.000 15.947 0.000 {method 'timestamp' of 'datetime.datetime' objects}



Why the date.timestamp takes 15.9 sec? Is this profiler error ?



Spawn:



# Start processes
for index, simulation in enumerate(self.simulations):
proc = Process(target=simulation_runner, args=(simulation, queues[index]))
jobs.append(proc)
proc.start()


Timestamp:



timestamp = math.floor(date.timestamp())


Also I wrote the program that do the same:



import time
from multiprocessing import Pool
from datetime import datetime


def worker(file_name):
with open(file_name, 'r+') as file:
for line in file:
date = datetime.now()
date.timestamp()


if __name__ == "__main__":
start = time.time()
args = ['FLT-TEST', 'FLT-TEST']
pool = Pool()
pool.map(worker, args)
# worker('FLT-TEST')
print(f'Executing in {time.time() - start} s.')


Without spawning it prints Executing in 0.16368794441223145 s.
With spawning it prints Executing in 66.31291604042053 s.
FLT-TEST contains 91849 lines



Without file reading



import time
from multiprocessing import Pool
from datetime import datetime


def worker(num):
print(f'Process {num}')
for _ in range(95000):
date = datetime.now()
date.timestamp()


if __name__ == "__main__":
start = time.time()
args = [1, 2]
pool = Pool()
pool.map(worker, args)
# worker(1)
print(f'Executing in {time.time() - start} s.')


I get the same results.










share|improve this question
























  • It's probably due to the processing involved of having the OS create and launch a separate task. multiprocessing can involve a lot of overhead.
    – martineau
    Nov 21 '18 at 7:26










  • Comment: You should consider using a time.perf_counter() for timing stuff like this.
    – martineau
    Nov 21 '18 at 7:31
















-1














I created a program that spawn processes and run the provided algorithm. When I run the algorithm without multiprocessing it takes 1.7 sec, but when I spawn two processes that run the same algorithm it takes 18 sec.



Profiler result for one process without spawning:
68050 0.084 0.000 0.084 0.000 {method 'timestamp' of 'datetime.datetime' objects}



With spawning two processes for one of spawned processes:
34025 15.947 0.000 15.947 0.000 {method 'timestamp' of 'datetime.datetime' objects}



Why the date.timestamp takes 15.9 sec? Is this profiler error ?



Spawn:



# Start processes
for index, simulation in enumerate(self.simulations):
proc = Process(target=simulation_runner, args=(simulation, queues[index]))
jobs.append(proc)
proc.start()


Timestamp:



timestamp = math.floor(date.timestamp())


Also I wrote the program that do the same:



import time
from multiprocessing import Pool
from datetime import datetime


def worker(file_name):
with open(file_name, 'r+') as file:
for line in file:
date = datetime.now()
date.timestamp()


if __name__ == "__main__":
start = time.time()
args = ['FLT-TEST', 'FLT-TEST']
pool = Pool()
pool.map(worker, args)
# worker('FLT-TEST')
print(f'Executing in {time.time() - start} s.')


Without spawning it prints Executing in 0.16368794441223145 s.
With spawning it prints Executing in 66.31291604042053 s.
FLT-TEST contains 91849 lines



Without file reading



import time
from multiprocessing import Pool
from datetime import datetime


def worker(num):
print(f'Process {num}')
for _ in range(95000):
date = datetime.now()
date.timestamp()


if __name__ == "__main__":
start = time.time()
args = [1, 2]
pool = Pool()
pool.map(worker, args)
# worker(1)
print(f'Executing in {time.time() - start} s.')


I get the same results.










share|improve this question
























  • It's probably due to the processing involved of having the OS create and launch a separate task. multiprocessing can involve a lot of overhead.
    – martineau
    Nov 21 '18 at 7:26










  • Comment: You should consider using a time.perf_counter() for timing stuff like this.
    – martineau
    Nov 21 '18 at 7:31














-1












-1








-1







I created a program that spawn processes and run the provided algorithm. When I run the algorithm without multiprocessing it takes 1.7 sec, but when I spawn two processes that run the same algorithm it takes 18 sec.



Profiler result for one process without spawning:
68050 0.084 0.000 0.084 0.000 {method 'timestamp' of 'datetime.datetime' objects}



With spawning two processes for one of spawned processes:
34025 15.947 0.000 15.947 0.000 {method 'timestamp' of 'datetime.datetime' objects}



Why the date.timestamp takes 15.9 sec? Is this profiler error ?



Spawn:



# Start processes
for index, simulation in enumerate(self.simulations):
proc = Process(target=simulation_runner, args=(simulation, queues[index]))
jobs.append(proc)
proc.start()


Timestamp:



timestamp = math.floor(date.timestamp())


Also I wrote the program that do the same:



import time
from multiprocessing import Pool
from datetime import datetime


def worker(file_name):
with open(file_name, 'r+') as file:
for line in file:
date = datetime.now()
date.timestamp()


if __name__ == "__main__":
start = time.time()
args = ['FLT-TEST', 'FLT-TEST']
pool = Pool()
pool.map(worker, args)
# worker('FLT-TEST')
print(f'Executing in {time.time() - start} s.')


Without spawning it prints Executing in 0.16368794441223145 s.
With spawning it prints Executing in 66.31291604042053 s.
FLT-TEST contains 91849 lines



Without file reading



import time
from multiprocessing import Pool
from datetime import datetime


def worker(num):
print(f'Process {num}')
for _ in range(95000):
date = datetime.now()
date.timestamp()


if __name__ == "__main__":
start = time.time()
args = [1, 2]
pool = Pool()
pool.map(worker, args)
# worker(1)
print(f'Executing in {time.time() - start} s.')


I get the same results.










share|improve this question















I created a program that spawn processes and run the provided algorithm. When I run the algorithm without multiprocessing it takes 1.7 sec, but when I spawn two processes that run the same algorithm it takes 18 sec.



Profiler result for one process without spawning:
68050 0.084 0.000 0.084 0.000 {method 'timestamp' of 'datetime.datetime' objects}



With spawning two processes for one of spawned processes:
34025 15.947 0.000 15.947 0.000 {method 'timestamp' of 'datetime.datetime' objects}



Why the date.timestamp takes 15.9 sec? Is this profiler error ?



Spawn:



# Start processes
for index, simulation in enumerate(self.simulations):
proc = Process(target=simulation_runner, args=(simulation, queues[index]))
jobs.append(proc)
proc.start()


Timestamp:



timestamp = math.floor(date.timestamp())


Also I wrote the program that do the same:



import time
from multiprocessing import Pool
from datetime import datetime


def worker(file_name):
with open(file_name, 'r+') as file:
for line in file:
date = datetime.now()
date.timestamp()


if __name__ == "__main__":
start = time.time()
args = ['FLT-TEST', 'FLT-TEST']
pool = Pool()
pool.map(worker, args)
# worker('FLT-TEST')
print(f'Executing in {time.time() - start} s.')


Without spawning it prints Executing in 0.16368794441223145 s.
With spawning it prints Executing in 66.31291604042053 s.
FLT-TEST contains 91849 lines



Without file reading



import time
from multiprocessing import Pool
from datetime import datetime


def worker(num):
print(f'Process {num}')
for _ in range(95000):
date = datetime.now()
date.timestamp()


if __name__ == "__main__":
start = time.time()
args = [1, 2]
pool = Pool()
pool.map(worker, args)
# worker(1)
print(f'Executing in {time.time() - start} s.')


I get the same results.







python multiprocessing






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 21 '18 at 7:22









martineau

65.8k989177




65.8k989177










asked Nov 21 '18 at 6:41









Григорий Дикий

6610




6610












  • It's probably due to the processing involved of having the OS create and launch a separate task. multiprocessing can involve a lot of overhead.
    – martineau
    Nov 21 '18 at 7:26










  • Comment: You should consider using a time.perf_counter() for timing stuff like this.
    – martineau
    Nov 21 '18 at 7:31


















  • It's probably due to the processing involved of having the OS create and launch a separate task. multiprocessing can involve a lot of overhead.
    – martineau
    Nov 21 '18 at 7:26










  • Comment: You should consider using a time.perf_counter() for timing stuff like this.
    – martineau
    Nov 21 '18 at 7:31
















It's probably due to the processing involved of having the OS create and launch a separate task. multiprocessing can involve a lot of overhead.
– martineau
Nov 21 '18 at 7:26




It's probably due to the processing involved of having the OS create and launch a separate task. multiprocessing can involve a lot of overhead.
– martineau
Nov 21 '18 at 7:26












Comment: You should consider using a time.perf_counter() for timing stuff like this.
– martineau
Nov 21 '18 at 7:31




Comment: You should consider using a time.perf_counter() for timing stuff like this.
– martineau
Nov 21 '18 at 7:31












1 Answer
1






active

oldest

votes


















1














timestamp = math.floor(date.replace(tzinfo=timezone.utc).timestamp())


Setting timezone fixed time duration.






share|improve this answer





















    Your Answer






    StackExchange.ifUsing("editor", function () {
    StackExchange.using("externalEditor", function () {
    StackExchange.using("snippets", function () {
    StackExchange.snippets.init();
    });
    });
    }, "code-snippets");

    StackExchange.ready(function() {
    var channelOptions = {
    tags: "".split(" "),
    id: "1"
    };
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using("snippets", function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: true,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: 10,
    bindNavPrevention: true,
    postfix: "",
    imageUploader: {
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    },
    onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53406517%2fmultiprocessing-timestamp-takes-a-lot-of-time%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    1














    timestamp = math.floor(date.replace(tzinfo=timezone.utc).timestamp())


    Setting timezone fixed time duration.






    share|improve this answer


























      1














      timestamp = math.floor(date.replace(tzinfo=timezone.utc).timestamp())


      Setting timezone fixed time duration.






      share|improve this answer
























        1












        1








        1






        timestamp = math.floor(date.replace(tzinfo=timezone.utc).timestamp())


        Setting timezone fixed time duration.






        share|improve this answer












        timestamp = math.floor(date.replace(tzinfo=timezone.utc).timestamp())


        Setting timezone fixed time duration.







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 21 '18 at 8:20









        Григорий Дикий

        6610




        6610






























            draft saved

            draft discarded




















































            Thanks for contributing an answer to Stack Overflow!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            To learn more, see our tips on writing great answers.





            Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


            Please pay close attention to the following guidance:


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53406517%2fmultiprocessing-timestamp-takes-a-lot-of-time%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            Wiesbaden

            Marschland

            Dieringhausen