On Fri, Jul 26, 2013 at 9:26 PM, Gregory P. Smith <g...@krypto.org> wrote: > > On Fri, Jul 26, 2013 at 3:23 PM, Antoine Pitrou <solip...@pitrou.net> wrote: >> >> On Sat, 27 Jul 2013 00:18:40 +0200 >> Victor Stinner <victor.stin...@gmail.com> wrote: >> > 2013/7/26 Antoine Pitrou <solip...@pitrou.net>: >> > > On Fri, 26 Jul 2013 22:17:47 +0200 >> > >> """ >> > >> On Linux, setting the close-on-flag has a low overhead on >> > >> performances. Results of bench_cloexec.py on Linux 3.6: >> > >> >> > >> - close-on-flag not set: 7.8 us >> > >> - O_CLOEXEC: 1% slower (7.9 us) >> > >> - ioctl(): 3% slower (8.0 us) >> > >> - fcntl(): 3% slower (8.0 us) >> > >> """ >> > > >> > > You aren't answering my question: slower than what? >> > >> > Ah, you didn't understand the labels. bench_cloexec.py runs a >> > benchmark on os.open(path, os.O_RDONLY, cloexec=False) and >> > os.open(path, os.O_RDONLY, cloexec=True) with different implementation >> > of making the file descriptor non-inheritable. >> > >> > close-on-flag not set: 7.8 us >> > => C code: open(path, O_RDONLY) >> > >> > O_CLOEXEC: 1% slower (7.9 us) >> > => C code: open(path, O_RDONLY|CLOEXEC) >> > => 1% slower than open(path, O_RDONLY) >> > >> > ioctl(): 3% slower (8.0 us) >> > => C code: fd=open(path, O_RDONLY); ioctl(fd, FIOCLEX, 0) >> > => 3% slower than open(path, O_RDONLY) >> > >> > fcntl(): 3% slower (8.0 us) >> > => C code: fd=open(path, O_RDONLY); flags = fcntl(fd, F_GETFD); >> > fcntl(fd, F_SETFD, flags | FD_CLOEXEC) >> > => 3% slower than open(path, O_RDONLY) >> >> Ok, so I think this it is a totally reasonable compromise. >> >> People who bother about a 3% slowdown when calling os.open() can >> optimize the hell out of their code using Cython for all I care :-) >> > > +1 ;) > > and +1 for making the sane default of noinherit / cloexec / > whatever-others-call-it by default for all fds/handles ever opened by > Python. It stops ignoring the issue (ie: the status quo of matching the > default behavior of C as defined in the 1970s)... That is a GOOD thing. :)
Do we even need a new PEP, or should we just do it? Or can we adapt Victor's PEP 446? -- --Guido van Rossum (python.org/~guido) _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
