Re: Potential show-stopper in em driver?

On Sun, Aug 13, 2023 at 6:55 PM Greg 'groggy' Lehey <grog@freebsd.org> wrote:
>
> I've spent the last couple of days chasing random hangs on my -CURRENT
> box.  It seems to be related to the Ethernet driver (em).  I've been
> trying without much success to chase it down, and I'd be grateful.
> The box is headless, and all communication is via the net, which
> doesn't make it any easier.  I've tried a verbose boot, but nothing of
> interest shows up.  Typically it happens during the nightly backups,
> which are over NFS:
>
>   Aug 13 21:06:46 dereel kernel: <<<66>n>nffs server s6>neurekfs server aeureka:/dum:p: /ndoump: tnot responding
>   Aug 13 21:06:46 dereel kernel:
>   Aug 13 21:06:46 dereel kernel: responding
>   Aug 13 21:06:46 dereel kernel:
>   Aug 13 21:06:46 dereel kernel: server eureka:/dump:n not responding
>
> And if you haven't seen those garbled messages before, admire.
> They've been there for a long time, and they have nothing to do with
> the problem.  More to the point, there are no other error messages.
>
> I've run three kernels on this box over the last few weeks:
>
> 1. FreeBSD dereel 14.0-CURRENT FreeBSD 14.0-CURRENT amd64 1400093 #10 main-n264292-7f9318a022ef: Mon Jul 24 17:13:32 AEST 2023     grog@dereel:/usr/obj/eureka/home/src/FreeBSD/git/main/amd64.amd64/sys/GENERIC amd64
>
>    This works with no problems.
>
> 2. FreeBSD 14.0-CURRENT amd64 1400094 #11 main-n264653-517e0978db1f: Thu Aug 10 14:17:13 AEST 2023 grog@dereel:/usr/obj/eureka/home/src/FreeBSD/git/main/amd64.amd64/sys/GENERIC
>
> 3. FreeBSD dereel 14.0-ALPHA1 FreeBSD 14.0-ALPHA1 amd64 1400094 #12 main-n264693-b231322dbe95: Sat Aug 12 14:31:44 AEST 2023     grog@dereel:/usr/obj/eureka/home/src/FreeBSD/git/main/amd64.amd64/sys/GENERIC amd64
>
>    Both of these exhibit the problem.
>
> Note that we're now ALPHA1, so it's a good idea to get to the bottom
> of it.  The box is an ThinkCentre M93p.  I'm attaching a verbose boot
> log, though I don't expect anybody to find something of use there.
> I'm also currently building a new world in case something has happened
> since Saturday.

The verbose boot didn't make it in the email.  'dmesg | grep
em<interface number>' would be a good enough start.

Can you post 'sysctl dev.em.<interface number>' from the machine after
a lockup?  Since you don't seem to have OOB access you may have to get
creative with cron or something.

> Greg
> --
> Sent from my desktop computer.
> See complete headers for address and phone numbers.
> This message is digitally signed.  If your Microsoft mail program
> reports problems, please read http://lemis.com/broken-MUA.php