[issue12655] Expose sched.h functions

Roundup Robot added the comment: New changeset fb975cb8fb45 by Victor Stinner in branch 'default': Issue #12655: Mention multiprocessing.cpu_count() in os.sched_getaffinity() doc http://hg.python.org/cpython/rev/fb975cb8fb45 -- ___ Python tracker

[issue12655] Expose sched.h functions

Antoine Pitrou added the comment: Ok, I've improved the default ncpus value and committed. -- resolution: -> fixed status: open -> closed ___ Python tracker ___

[issue12655] Expose sched.h functions

Roundup Robot added the comment: New changeset d6745ddbccbd by Antoine Pitrou in branch 'default': Issue #12655: Instead of requiring a custom type, os.sched_getaffinity and http://hg.python.org/cpython/rev/d6745ddbccbd -- ___ Python tracker

[issue12655] Expose sched.h functions

Serhiy Storchaka added the comment: > You may also use a constant size (CPU_SETSIZE) of the set used by sched_setaffinity() to simplify the code. As Antoine pointed out to me (and I was convinced itself, experimented with an example from man:CPU_SET(3)) the cpu_set functions work with a sets of

[issue12655] Expose sched.h functions

Giampaolo Rodola' added the comment: +1 for Antoine's patch/approach: it's more usable and pythonic. I think documentation should mention and link the existence of: http://docs.python.org/library/multiprocessing.html#multiprocessing.cpu_count -- ___ P

[issue12655] Expose sched.h functions

STINNER Victor added the comment: >> Try with an initial value of ncpus=1. > Well, I've tried and it works: Oh, you're right :-) I only checked ncpus (1), not the final result. It works because CPU_ALLOC_SIZE() rounds the size using sizeof(unsigned long) (64 bits on my CPU). So CPU_ALLOC_SIZE(1)

[issue12655] Expose sched.h functions

Antoine Pitrou added the comment: > Try with an initial value of ncpus=1. Well, I've tried and it works: >>> os.sched_getaffinity(0) {0, 1, 2, 3} > I don't know if CPU_SETSIZE is part of the standard (POSIX?). These are Linux-specific functions. -- __

[issue12655] Expose sched.h functions

STINNER Victor added the comment: sched_getaffinity() does not fail if the set is smaller than the number of CPU. Try with an initial value of ncpus=1. So we cannot start the heuristic with ncpus=16, because it would only return 16 even if the computer has more cpus. Instead of this heuristic, w

[issue12655] Expose sched.h functions

Changes by Antoine Pitrou : Added file: http://bugs.python.org/file26683/cpuset.patch ___ Python tracker ___ ___ Python-bugs-list mailing list

[issue12655] Expose sched.h functions

Changes by Antoine Pitrou : Removed file: http://bugs.python.org/file26682/cpuset.patch ___ Python tracker ___ ___ Python-bugs-list mailing li

[issue12655] Expose sched.h functions

Antoine Pitrou added the comment: Here is a patch removing cpu_set and using sets of integers instead. -- Added file: http://bugs.python.org/file26682/cpuset.patch ___ Python tracker ___

[issue12655] Expose sched.h functions

Benjamin Peterson added the comment: Using a Python set is fine. -- ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscri

[issue12655] Expose sched.h functions

Antoine Pitrou added the comment: > Is it possible to get the number of CPU to be able to convert a Python > set to a cpu_set? sched_getaffinity returns EINVAL if the cpu_set is too small, so it should be easy enough to iterate. I agree the API should be changed for something saner, and before

[issue12655] Expose sched.h functions

STINNER Victor added the comment: I'm sorry, I missed this issue. I just saw its API and I have remarks on the cpu_set type: * Why not reusing the set type for input parameters and the result of sched_getaffinity? * Method names of cpu_set are very different than names of the set type * Why

[issue12655] Expose sched.h functions

Changes by Giampaolo Rodola' : -- nosy: +giampaolo.rodola ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: http:

[issue12655] Expose sched.h functions

Matt Joiner added the comment: Please also expose sched_getcpu(). -- nosy: +anacrolix ___ Python tracker ___ ___ Python-bugs-list mai

[issue12655] Expose sched.h functions

Roundup Robot added the comment: New changeset 89e92e684b37 by Benjamin Peterson in branch 'default': expose sched.h functions (closes #12655) http://hg.python.org/cpython/rev/89e92e684b37 -- nosy: +python-dev resolution: -> fixed stage: patch review -> committed/rejected status: open

[issue12655] Expose sched.h functions

Changes by Benjamin Peterson : Added file: http://bugs.python.org/file22805/sched_stuff.patch ___ Python tracker ___ ___ Python-bugs-list mail

[issue12655] Expose sched.h functions

Benjamin Peterson added the comment: 2011/7/30 Charles-François Natali : > > Charles-François Natali added the comment: > >> I actually implemented this because I wanted to confine a Python process to >> a cpu to prevent keep it from being tossed from core to core. It made sense >> to bring t

[issue12655] Expose sched.h functions

Charles-François Natali added the comment: > I actually implemented this because I wanted to confine a Python process to a > cpu to prevent keep it from being tossed from core to core. It made sense to > bring the other scheduling functions along for the ride. Why didn't you use something lik

[issue12655] Expose sched.h functions

Changes by Benjamin Peterson : Added file: http://bugs.python.org/file22797/sched_stuff.patch ___ Python tracker ___ ___ Python-bugs-list mail

[issue12655] Expose sched.h functions

Benjamin Peterson added the comment: I actually implemented this because I wanted to confine a Python process to a cpu to prevent keep it from being tossed from core to core. It made sense to bring the other scheduling functions along for the ride. --

[issue12655] Expose sched.h functions

Charles-François Natali added the comment: I'm +0. It would certainly be fun, but I'm not so sure about the "profit" part. The main usage of the scheduler API is for real-time policies, and I somehow doubt Python is commonly used in this area (but I could be wrong). Furthermore, the same functio

[issue12655] Expose sched.h functions

Antoine Pitrou added the comment: Haven't reviewed the implementation, but +1 for adding this functionality. As for splitting apart posixmodule.c, I agree that's a separate concern. Something like the _io module splitup (several C files compiled in a single extension module) looks workable.

[issue12655] Expose sched.h functions

Benjamin Peterson added the comment: 2011/7/29 Amaury Forgeot d'Arc : > > Amaury Forgeot d'Arc added the comment: > >> @@ -10330,26 +10899,34 @@ INITFUNC(void) > I know that it's only an increase of 5%, but I feel that posixmodule.c is > already large enough. > Does this feature belongs to the

[issue12655] Expose sched.h functions

Amaury Forgeot d'Arc added the comment: > @@ -10330,26 +10899,34 @@ INITFUNC(void) I know that it's only an increase of 5%, but I feel that posixmodule.c is already large enough. Does this feature belongs to the os module? Or is it time to split posixmodule.c in several pieces? -- nosy

[issue12655] Expose sched.h functions

New submission from Benjamin Peterson : For fun and profit. :) -- components: Extension Modules files: sched_stuff.patch keywords: patch messages: 141401 nosy: benjamin.peterson, pitrou priority: normal severity: normal status: open title: Expose sched.h functions type: feature request v