Charles-François Natali added the comment: > Specifying a big blocksize doesn't mean the transfer will be faster. > send/sendfile won't send more than a certain amount of bytes anyways.
The transfer won't be faster mainly because it's really I/O bound. But it will use less CPU, only because you're making less syscalls. > If I'm not mistaken I recall from previous benchmarks that after a certain > point (131072 or something) increasing the blocksize results in equal or even > worse performances. I can perfectly believe this for a send loop, maybe because you're exceeding the socket buffer size, or because your working set doesn't fit into caches anymore, etc. But for sendfile(), I don't see how calling it repeatedly could not be slower than calling it once with the overall size: that's how netperf and vsftpd use it, and probably others. > Another thing I don't like is that by doing so you implicitly assume that the > file is "fstat-eable". I don't know if there are cases where it's not, but > the less assumptions we do the better. Well, the file must be mmap-able, so I doubt fstat() is the biggest concern... ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue13564> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
