[gPXE] [Etherboot-developers] [PATCH] [tftp] Kick off TFTP RRQ from a process to avoid losing first packet

[Stefan Hajnoczi]

On Thu, Jan 14, 2010 at 2:35 PM, Joshua Oreman <oremanj at rwcr.net> wrote:
> On Thu, Jan 14, 2010 at 9:20 AM, Thomas Horsten <thomas at horsten.com> wrote:
>> That would probably be good. Again the wait objects I mentioned
>> earlier, or even a simple callback in the socket structure would be an
>> idea.
>
> Keep in mind that gPXE has extremely limited code size constraints; I
> suspect this is why Stefan didn't want to use an actual process for
> the TFTP fix when something lighter-weight would do.

Yes.  I like the idea of a wait queue, it's a powerful primitive.
However it is not essential to have it, and that's how gPXE manages to
pack so much punch into 64 KB - it focuses on the essentials.

> My opinion on the
> ARP issue: it's only going to get hit once per TFTP server, which is a
> lot less than once per file, and can probably be ignored barring
> evidence to the contrary.

Good point.  Our ARP cache never expires entries.

Stefan