Re: call for bge(4) testers

From: Gleb Smirnoff <glebius_at_FreeBSD.org>
Date: Wed, 23 Aug 2006 15:06:19 +0400
On Wed, Aug 23, 2006 at 07:51:18PM +0900, Pyun YongHyeon wrote:
P>  > P> Its sole purpose is to reinitialize hardware for real watchdog
P>  > P> timeouts. It's not fix for general watchdog timeouts. As I said other
P>  > P> mails, the fake watchdog timeout(losing Tx interrupts) for hardwares
P>  > P> with Tx interrupt moderation capability could be normal thing. So I
P>  > P> just want to know bge(4) also has the same feature(bug).
P>  > 
P>  > According to several emails about em(4) fake watchdog timeouts, the
P>  > problem can be fixed by setting debug.mpsafenet=0. This makes me think
P>  > that the problem isn't caused by TX interrupt moderation, but some race
P>  > in the kernel. Really, if_slowtimo() doesn't acquire driver lock before
P>  > checking and modifying the if_timer field.
P>  > 
P> 
P> Hmm... I didn't say the problem was caused by TX interrupt moderation.
P> I can't sure but I'm under the impression it has *two* different issues.
P> If you think fake watchdog timeout fix is not adequate one please
P> let me know. I'll backout the change if you want.

I don't think you should backout it until we find a solution.
However, I'd ask you don't MFC it.

P>  > Afaik, NIC drivers that can do interrupt moderation should set a timer
P>  > to a sane value, based on interrupt moderation settings, so that the
P>  > watchdog won't be ever called fakely.
P> 
P> Yes. Normally it should. But I saw the issues on Marvell Yukon too.

Does Marvell Yukon have interrupt moderation?

-- 
Totus tuus, Glebius.
GLEBIUS-RIPN GLEB-RIPE
Received on Wed Aug 23 2006 - 09:06:23 UTC

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