svn commit: r281942 - head/sys/vm

[Chagin Dmitry]

On Fri, Apr 24, 2015 at 05:03:53PM +0000, Scott Long wrote:
> Author: scottl
> Date: Fri Apr 24 17:03:53 2015
> New Revision: 281942
> URL: https://svnweb.freebsd.org/changeset/base/281942
> 
> Log:
>   Revert r281451.  It causes a panic/hang early in boot for a number of
>   users, myself included.  The original code is likely papering over a
>   larger bug that needs to be explored, but for now get things back to
>   a working state.
>   
>   Obtained from:	Netflix, Inc.
>   MFC after:	immediately
> 
in my POV, at vm_mem_init stage vm_map_init() call
uma_zcreate() that uses uinitialized zones (which initialized
in uma_startup()). I bet zones contains garbage.

I see very similar bug that appears in kern_clocksource.c:579.
The per cpu et_hw_mtx contains some garbage data before mtx_init(),
it seems that something corrupts the kernel memory after teh kernel
is loaded.
Unfortunately, I did not succeed to catch the intruder. It is strange,
that hw breakpoints does not help.

-- 
Have fun!
chd