[Libguestfs] [PATCH libnbd] states: In recv_into_rbuf and send_from_wbuf loop until EAGAIN.

[Richard W.M. Jones]

I thought this should produce a fairly dramatic performance gain.  In
fact I couldn't measure any performance difference at all.  I think
what's happening is we're actually paying an extra syscall (to
discover the socket would block) and then doing the poll anyway.

So I don't know if it's worth having this patch.  It could be argued
that it makes the code shorter (therefore simpler), so I'm posting it,
but I'm ambivalent.

Rich.