freebsd stable - Aug 2015 - ia64 stable/10 r286316: hang at Entering /boot/kernel/kernel

On Thu, Aug 27, 2015 at 01:12:16PM +0100, Anton Shterenlikht
wrote:
> ia64 stable/10 r286315 boots, but 
> r286316 hangs at "Entering /boot/kernel/kernel".
> 
> Please advise
To state an obvious thing.  The commit which you pointed to, changes
the code which is not executed at that early kernel boot stage.  The
revision cannot cause the consequences you described.

I think that you either have build-environment issue which randomly pops
up, or there is some other boot-time issue which is sporadic.  The only
suggestion I have, try many boots with kernels which look either good
or bad, I would be not surprised if statistic would be completely
different from binary good/bad outcome.

Otherwise, I do not have an idea.

> On Aug 27, 2015, at 9:23 AM, Konstantin Belousov <kostikbel at
gmail.com> wrote:
> 
> On Thu, Aug 27, 2015 at 01:12:16PM +0100, Anton Shterenlikht wrote:
>> ia64 stable/10 r286315 boots, but
>> r286316 hangs at "Entering /boot/kernel/kernel".
>> 
>> Please advise
> 
> To state an obvious thing.  The commit which you pointed to, changes
> the code which is not executed at that early kernel boot stage.  The
> revision cannot cause the consequences you described.
Failures may not always be obvious. The ia64 kernel has a fixed array
for relocations and a harmless piece of code, which may actually never
be called, could result in additional relocations that case the array
to overflow and do bad things on boot.

All I?m saying is: give Anton the benefit of the doubt. He has spent
a lot of time with ia64 and knows quite a bit about its behavior. We
simply do not know what?s going on and he has provided us with a lead.
We go from there...

--
Marcel Moolenaar
marcel at xcllnt.net

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>From kostikbel at gmail.com Thu Aug 27 18:22:37 2015
>
>On Thu, Aug 27, 2015 at 01:12:16PM +0100, Anton Shterenlikht wrote:
>> ia64 stable/10 r286315 boots, but 
>> r286316 hangs at "Entering /boot/kernel/kernel".
>> 
>> Please advise
>
>To state an obvious thing.  The commit which you pointed to, changes
>the code which is not executed at that early kernel boot stage.  The
>revision cannot cause the consequences you described.
yes, I'm surprised too.
>I think that you either have build-environment issue which randomly pops
>up, or there is some other boot-time issue which is sporadic.  The only
>suggestion I have, try many boots with kernels which look either good
>or bad, I would be not surprised if statistic would be completely
>different from binary good/bad outcome.
>
>Otherwise, I do not have an idea.
>
I doubt it's a random or a sporadic issue.
I did a bisection, as suggested, during which
I built world/kernel on 7 revisions, and when I
narrowed it down to <50, a further 4 kernels.
All kernels <=286315 boot, all kernels >= 286316
do not. I think if it were something random,
it wouldn't be such a clear cut picture.

What about my loader.conf:

# cat /boot/loader.conf 
zfs_load="YES"
# soft limits
kern.dfldsiz=536748032  # default soft limit for process data
kern.dflssiz=536748032  # default soft limit for stack
# hard limits
kern.maxdsiz=536748032  # hard limit for process data
kern.maxssiz=536748032  # hard limit for stack
kern.maxtsiz=536748032  # hard limit for text size
                        # processes may not exceed these limits.
# 

My memory:

real memory  = 8589934592 (8192 MB)
avail memory = 8387649536 (7999 MB)

I'll try disabling all these settings in loader.conf
and see if makes a difference.
But these settings have been there for a few years
with no problems.

Anton