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 :-) Regards Antoine. _______________________________________________ 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
