In message <200109102012.f8AKCN527631@guinevere.selresearch.net>
kml@selresearch.net writes:

[... snip lots ...]

>It's not so much that I think adding fsync() is a bad idea, I'm just
>too lazy to go digging through libc to make it happen.  Do FreeBSD
>and Linux do this (in which case, I guess I better)?

I dunno about fsync(), but Linux has the opposite: cork and uncork.
TCP_CORK completely disables further writes of less-than-full frames.
The motivation is an app like sendfile(): squirt out "metadata"
(HTTP mime headers) first, then send the file data in full frames
(Or 8k chunks on jumbo ethernet, I guess).