3 ms·
> sendfile() is file-to-socket (zero-copy as well), and has very high performance as well, for both Linux and BSDs. It only supports file-to-socket, however, an
by messe 1y ago
> sendfile() is file-to-socket (zero-copy as well), and has very high performance as well, for both Linux and BSDs. It only supports file-to-socket, however, and well, to stay relevant, sendmsg() can't be used with pipes in the general case, it is for UNIX domain sockets, INET sockets, and other socket types.
On Linux, sendfile supports more than just file to socket, as it's implemented using splice. I've used it for file-to-block-device in the past.
- johnisgood 1y agoOn BSDs probably not, as they don't have splice, but that is good to know. I wonder if on BSDs it really is readv() and writev() that are the fastest way to achieve the same thing as has been done in the article. Maybe I am missing something. I would like to be corrected.
- messe 1y agoAFAIK, neither OpenBSD nor NetBSD has sendfile. On FreeBSD, I think you're correct regarding it being file-to-socket only.
- zambal 1y agoIndeed, if I'm not mistaken Netflix at least used to use (and commit to kernel) FreeBSD on content servers because of its superior sendfile performance
- messe 1y agoNot only that, but they even contributed patches to allow the FreeBSD kernel to handle the TLS part of SSL_sendfile as well[1]. [1]: https://man.freebsd.org/cgi/man.cgi?ktls(4) https://man.freebsd.org/cgi/man.cgi?ktls(4)