Message 129890 - Python tracker

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Author	neologix
Recipients	Aaron.Sherman, giampaolo.rodola, gregory.p.smith, neologix, pitrou, vstinner
Date	2011-03-02.13:13:38
SpamBayes Score	1.7343759e-06
Marked as misclassified	No
Message-id	<1299071619.33.0.572439984781.issue11314@psf.upfronthosting.co.za>
In-reply-to

Content
> So, even though implemented in C, the file descriptor closing logic is still quite costly! Yes, see this recent issue: http://bugs.python.org/issue11284 In the reporter's case, it's much worse, because FreeBSD (at least the version he's using) has a SC_OPEN_MAX of 655000, so that passing close_fds=True bumps the Popen runtime to 3 seconds! Some Unix offer a closefrom() or similar function to close all open file descriptors (and only open ones), which should be much faster. I'm not aware of anything equivalent under Linux, but it might be worth looking into.

> So, even though implemented in C, the file descriptor closing logic is still quite costly!

Yes, see this recent issue: http://bugs.python.org/issue11284

In the reporter's case, it's much worse, because FreeBSD (at least the version he's using) has a SC_OPEN_MAX of 655000, so that passing close_fds=True bumps the Popen runtime to 3 seconds!
Some Unix offer a closefrom() or similar function to close all open file descriptors (and only open ones), which should be much faster.
I'm not aware of anything equivalent under Linux, but it might be worth looking into.

History
Date	User	Action	Args
2011-03-02 13:13:39	neologix	set	recipients: + neologix, gregory.p.smith, pitrou, vstinner, giampaolo.rodola, Aaron.Sherman
2011-03-02 13:13:39	neologix	set	messageid: <1299071619.33.0.572439984781.issue11314@psf.upfronthosting.co.za>
2011-03-02 13:13:38	neologix	link	issue11314 messages
2011-03-02 13:13:38	neologix	create