Re: Please test EARLY_AP_STARTUP

On Tue, Nov 29, 2016 at 2:27 AM, John Baldwin <jhb_at_freebsd.org> wrote:
> On Monday, November 28, 2016 02:35:07 PM Sepherosa Ziehau wrote:
>> Hi John,
>>
>> fdc seems to cause panic on Hyper-V:
>> https://people.freebsd.org/~sephe/fdc_panic.png
>
> You shouldn't get this panic in latest HEAD (post-r309148).


The base of my kernel tree is ~20 days old :)


>
>> I then commented out device fdc, and I fixed one panic on Hyper-V here:
>> https://reviews.freebsd.org/D8656
>
> Replied to the review.
>
>> After fdc is disabled and hyperv/storvsc is fixed, it seems to boot
>> fine, except a long delay (28~30seconds) here:
>> ....
>> Timecounters tick every 1.000 msec
>> -----
>> 28 ~ 30 seconds delay
>> -----
>> vlan: initialized, using hash tables with chaining
>> ....
>>
>> I have the bootverbose dmesg here:
>> https://people.freebsd.org/~sephe/dmesg_earlyap.txt
>>
>> I booted 10 times, only one boot does not suffer this 30 seconds
>> delay.  It sounds like some races to me.  Any hints?
>
> It is likely a race as we start running things sooner now, yes.  Can you
> break into DDB during the hang and see what thread0 is waiting on?  If
> it is in the interrupt hooks you can use 'show conifhk' in DDB to see the
> list of pending interrupt hooks.  That provides a list of candidate drivers
> to inspect (e.g. stack traces of relevant kthreads) for what is actually
> waiting (and what it is waiting on)

Just tried, but I failed to break into DDB during the 30 seconds
delay.  DDB was entered after the 30 seconds delay, though I press the
break key when the delay started.

Thanks,
sephe

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