Date: Thu, 11 Apr 2019 16:26:49 +0200 From: Jan Bramkamp <crest@rlwinm.de> To: freebsd-ports@freebsd.org Subject: Re: python 3 subprocess performance Message-ID: <8f3f8413-60f2-bb03-a6b4-4f6364cdc3df@rlwinm.de> In-Reply-To: <20190411161649.1b740d21@vm2.home.zagrebin.ru> References: <20190411161649.1b740d21@vm2.home.zagrebin.ru>
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Please run python under truss -f. Does it try to close(2) all possible
file descriptors? Does the runtime decrease if fdescfs is mounted at
/dev/fd?
On 11.04.19 15:16, Alexander Zagrebin wrote:
> Hi!
>
> I've noticed the subprocess performance issue with python 3.
> For example, this simple script takes just 0,15 second to complete
> with python 2.7, but more than 5 sec with python 3.6:
>
> import subprocess
>
> for i in range(100):
> p = subprocess.Popen(['uname', '-a'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
> (stdoutdata, stderrdata) = p.communicate()
>
> Profiling with the cProfile shows, that this excessive 5 seconds was
> wasted in the "{built-in method posix.read}"
>
> Could anybody confirm this issue?
>
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