Re: [9fans] Latest pull killed my server

[erik quanstrom <quanstro@quanstro.net>]

	/* compute log10(ether->mbps) into lg */
	for(lg = 0, mb = ether->mbps; mb >= 10; lg++)
		mb /= 10;
	if (lg > 0)
		lg--;
	if (lg > 14)			/* 2^(14+17) = 2⁳ⁱ */
		lg = 14;
	/* allocate larger output queues for higher-speed interfaces */
	bsz = 1UL << (lg + 17);		/* 2ⁱ⁷ = 128K, bsz = 2ⁿ × 128K */
	while (bsz > mainmem->maxsize / 8 && bsz > 128*1024)
		bsz /= 2;

	netifinit(ether, name, Ntypes, bsz);
>>	while (ether->oq == nil && bsz > 128*1024) {
		bsz /= 2;
		ether->oq = qopen(bsz, Qmsg, 0, 0);
		ether->limit = bsz;
	}
	if(ether->oq == nil)
		panic("etherreset %s", name);

the simple fix would be to change the > on the marked
line to >=.  but i think the while loop could be tossed
since malloc panics on failure and since qopen only allocates
sizeof(Queue) regardless of the limit argument.  i had
this code when i wrote the myricom driver (qio sets q->limit itself).

	j = ether->mbps;
	if(j > 1000)
		j *= 10;
	for(i = 0; j >= 100; i++)
		j /= 10;
	i = (128<<i) * 1024;
	netifinit(ether, name, Ntypes, i);
	if(ether->oq == nil)
		ether->oq = qopen(i, Qmsg, 0, 0);
	if(ether->oq == nil)
		panic("etherreset %s", name);

by the way, a quick scan shows
	ether2114x
	etherrhine
are capable of setting mbps to 0 on startup.  this should
be legal, since ethernet can be connected after boot.

- erik