How to limit and queue up processes in Python
Lets say I have 10000 tasks at hand. How can I process them in parallel, running precisely 8 processes at any time? The moment a task is finished, the next task should be fetched for execution immediately.
for e in arr:
pr=Process(target=execute, args=(q,e))
pr.start()
pr.join()
I want to do this because my CPU has only 8 hardware threads. Swarming it with 10000 tasks at once will slow down the overall computation due to the switching overhead. My memory is also limited.
(Edit: This is not a duplicate of this question as I am not asking how to fork a process.)
python python-3.x process parallel-processing python-3.6
add a comment |
Lets say I have 10000 tasks at hand. How can I process them in parallel, running precisely 8 processes at any time? The moment a task is finished, the next task should be fetched for execution immediately.
for e in arr:
pr=Process(target=execute, args=(q,e))
pr.start()
pr.join()
I want to do this because my CPU has only 8 hardware threads. Swarming it with 10000 tasks at once will slow down the overall computation due to the switching overhead. My memory is also limited.
(Edit: This is not a duplicate of this question as I am not asking how to fork a process.)
python python-3.x process parallel-processing python-3.6
3
Look at the Pool classes in the docs
– James K Polk
Nov 12 '18 at 5:11
1
Possible duplicate of How to process a list in parallel in Python?
– U9-Forward
Nov 12 '18 at 5:13
I don't think it is a duplicate of that question, as I am not asking how to fork a process. Anyway, Pool is probably the solution to my problem. Thanks, James!
– Chong Lip Phang
Nov 12 '18 at 5:17
add a comment |
Lets say I have 10000 tasks at hand. How can I process them in parallel, running precisely 8 processes at any time? The moment a task is finished, the next task should be fetched for execution immediately.
for e in arr:
pr=Process(target=execute, args=(q,e))
pr.start()
pr.join()
I want to do this because my CPU has only 8 hardware threads. Swarming it with 10000 tasks at once will slow down the overall computation due to the switching overhead. My memory is also limited.
(Edit: This is not a duplicate of this question as I am not asking how to fork a process.)
python python-3.x process parallel-processing python-3.6
Lets say I have 10000 tasks at hand. How can I process them in parallel, running precisely 8 processes at any time? The moment a task is finished, the next task should be fetched for execution immediately.
for e in arr:
pr=Process(target=execute, args=(q,e))
pr.start()
pr.join()
I want to do this because my CPU has only 8 hardware threads. Swarming it with 10000 tasks at once will slow down the overall computation due to the switching overhead. My memory is also limited.
(Edit: This is not a duplicate of this question as I am not asking how to fork a process.)
python python-3.x process parallel-processing python-3.6
python python-3.x process parallel-processing python-3.6
edited Nov 12 '18 at 5:31
asked Nov 12 '18 at 5:08
Chong Lip Phang
2,83843041
2,83843041
3
Look at the Pool classes in the docs
– James K Polk
Nov 12 '18 at 5:11
1
Possible duplicate of How to process a list in parallel in Python?
– U9-Forward
Nov 12 '18 at 5:13
I don't think it is a duplicate of that question, as I am not asking how to fork a process. Anyway, Pool is probably the solution to my problem. Thanks, James!
– Chong Lip Phang
Nov 12 '18 at 5:17
add a comment |
3
Look at the Pool classes in the docs
– James K Polk
Nov 12 '18 at 5:11
1
Possible duplicate of How to process a list in parallel in Python?
– U9-Forward
Nov 12 '18 at 5:13
I don't think it is a duplicate of that question, as I am not asking how to fork a process. Anyway, Pool is probably the solution to my problem. Thanks, James!
– Chong Lip Phang
Nov 12 '18 at 5:17
3
3
Look at the Pool classes in the docs
– James K Polk
Nov 12 '18 at 5:11
Look at the Pool classes in the docs
– James K Polk
Nov 12 '18 at 5:11
1
1
Possible duplicate of How to process a list in parallel in Python?
– U9-Forward
Nov 12 '18 at 5:13
Possible duplicate of How to process a list in parallel in Python?
– U9-Forward
Nov 12 '18 at 5:13
I don't think it is a duplicate of that question, as I am not asking how to fork a process. Anyway, Pool is probably the solution to my problem. Thanks, James!
– Chong Lip Phang
Nov 12 '18 at 5:17
I don't think it is a duplicate of that question, as I am not asking how to fork a process. Anyway, Pool is probably the solution to my problem. Thanks, James!
– Chong Lip Phang
Nov 12 '18 at 5:17
add a comment |
2 Answers
2
active
oldest
votes
I think if you split the "for" loop for join statement your problem might be solved. Right now you start a fork and want the result to come back and go do another fork process. And no fork is closed right now.
for e in arr:
pr=Process(target=execute, args=(q,e))
pr.start()
for e in arr:
pr.join()
Or just go with pool and map functions.
1
I am going for Pool.
– Chong Lip Phang
Nov 12 '18 at 5:27
add a comment |
For Pool to work here I need to call get() too.
from multiprocessing import Pool
pl=
pool = Pool(8)
for e in arr:
pl.append(pool.apply_async(execute, (e))
for pl2 in pl: pl2.get()
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
I think if you split the "for" loop for join statement your problem might be solved. Right now you start a fork and want the result to come back and go do another fork process. And no fork is closed right now.
for e in arr:
pr=Process(target=execute, args=(q,e))
pr.start()
for e in arr:
pr.join()
Or just go with pool and map functions.
1
I am going for Pool.
– Chong Lip Phang
Nov 12 '18 at 5:27
add a comment |
I think if you split the "for" loop for join statement your problem might be solved. Right now you start a fork and want the result to come back and go do another fork process. And no fork is closed right now.
for e in arr:
pr=Process(target=execute, args=(q,e))
pr.start()
for e in arr:
pr.join()
Or just go with pool and map functions.
1
I am going for Pool.
– Chong Lip Phang
Nov 12 '18 at 5:27
add a comment |
I think if you split the "for" loop for join statement your problem might be solved. Right now you start a fork and want the result to come back and go do another fork process. And no fork is closed right now.
for e in arr:
pr=Process(target=execute, args=(q,e))
pr.start()
for e in arr:
pr.join()
Or just go with pool and map functions.
I think if you split the "for" loop for join statement your problem might be solved. Right now you start a fork and want the result to come back and go do another fork process. And no fork is closed right now.
for e in arr:
pr=Process(target=execute, args=(q,e))
pr.start()
for e in arr:
pr.join()
Or just go with pool and map functions.
answered Nov 12 '18 at 5:22
ytamer
316
316
1
I am going for Pool.
– Chong Lip Phang
Nov 12 '18 at 5:27
add a comment |
1
I am going for Pool.
– Chong Lip Phang
Nov 12 '18 at 5:27
1
1
I am going for Pool.
– Chong Lip Phang
Nov 12 '18 at 5:27
I am going for Pool.
– Chong Lip Phang
Nov 12 '18 at 5:27
add a comment |
For Pool to work here I need to call get() too.
from multiprocessing import Pool
pl=
pool = Pool(8)
for e in arr:
pl.append(pool.apply_async(execute, (e))
for pl2 in pl: pl2.get()
add a comment |
For Pool to work here I need to call get() too.
from multiprocessing import Pool
pl=
pool = Pool(8)
for e in arr:
pl.append(pool.apply_async(execute, (e))
for pl2 in pl: pl2.get()
add a comment |
For Pool to work here I need to call get() too.
from multiprocessing import Pool
pl=
pool = Pool(8)
for e in arr:
pl.append(pool.apply_async(execute, (e))
for pl2 in pl: pl2.get()
For Pool to work here I need to call get() too.
from multiprocessing import Pool
pl=
pool = Pool(8)
for e in arr:
pl.append(pool.apply_async(execute, (e))
for pl2 in pl: pl2.get()
answered Nov 12 '18 at 6:02
Chong Lip Phang
2,83843041
2,83843041
add a comment |
add a comment |
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3
Look at the Pool classes in the docs
– James K Polk
Nov 12 '18 at 5:11
1
Possible duplicate of How to process a list in parallel in Python?
– U9-Forward
Nov 12 '18 at 5:13
I don't think it is a duplicate of that question, as I am not asking how to fork a process. Anyway, Pool is probably the solution to my problem. Thanks, James!
– Chong Lip Phang
Nov 12 '18 at 5:17