"sysctl -a" hangs multiuser boot

[Nathan Whitehorn]

On 07/19/11 11:19, Paul Mather wrote:
> I'm having problems with a kernel built today from a csup done today.  I'm using an Xserve G5 running FreeBSD/powerpc64 9-CURRENT.  The system will not boot up multiuser: it hangs at "Entropy harvesting: interrupts ethernet point_to_point" and gets no further.  I can't Ctrl-C to get the boot past that point.
>
> It appears it is the "sysctl -a" in the entropy kickstart portion of /etc/rc.d/initrandom that is causing the problem.
>
> If I do "sysctl -a" manually it will produce output so far and then no further.  Here are the last few lines before it stops outputting anything more:
>
> [[...]]
> hw.usb.ugen.debug: 0
> hw.usb.power_timeout: 30
> hw.usb.uhub.debug: 0
> hw.usb.no_pf: 0
> hw.usb.proc.debug: 0
> hw.usb.pr_recovery_delay: 250
> hw.usb.pr_poll_delay: 50
> hw.usb.uhid.debug: 0
> hw.usb.ukbd.no_leds: 0
> hw.usb.ukbd.debug: 0
> hw.usb.ums.debug: 0
>
>
>
> The system doesn't hang, but console input ceases to work and I can't SSH into the system any more.  I can still ping the machine, but ping times vary wildly, e.g.,
>
> 27 packets transmitted, 26 packets received, 3.7% packet loss
> round-trip min/avg/max/stddev = 57.076/708.818/1395.450/280.318 ms
>
> Those ping times are way higher than normal.  Here is an example of pinging the machine when it is not under the influence of doing a "sysctl -a":
>
> 23 packets transmitted, 23 packets received, 0.0% packet loss
> round-trip min/avg/max/stddev = 0.421/0.591/0.758/0.096 ms
>
>
> Also, at occasional intervals, this will be output on the console after having done a "sysctl -a":
>
> max66900: iicbus read failed
>
>
> (That's the only console output I have seen since issuing "sysctl -a".)
>
> The fans will occasionally race, but eventually be brought under control.
>
> For now, I have removed the "sysctl -a" from /etc/rc.d/initrandom so my system can boot, but I don't think that is a desirable long-term fix.
>
> Any ideas for a good long-term solution?
>

That's no good. Looks like USB is triggering an interrupt storm. I'll 
take a look in the next couple days.
-Nathan