Re: System freeze w/display strangeness on amd64/current

[Chuck Silvers <chuq%chuq.com@localhost>]

On Tue, Dec 27, 2011 at 07:52:29AM -0500, Gary Duzan wrote:
> In Message <20111225114643.GD11619%mail.duskware.de@localhost>,
>    Martin Husemann <martin%duskware.de@localhost>wrote:
> 
> =>On Fri, Dec 23, 2011 at 08:20:51PM -0500, Gary Duzan wrote:
> =>>    Any thoughts for diagnosing the problem? Loading older versions
> =>> would be possible, if a bit messy. dmesg included below.
> =>
> =>Just a very tiny straw, but you could try to comment out the 
> =>
> =>#define __HAVE_DIRECT_MAP 1
> =>#define __HAVE_MM_MD_DIRECT_MAPPED_IO
> =>#define __HAVE_MM_MD_DIRECT_MAPPED_PHYS
> =>
> =>block in /usr/src/sys/arch/amd64/include/types.h and build a new kernel.
> 
>    Thanks for this. I #if 0'd out those lines, and things seem much
> more stable now. I ran the full test suite and have been browsing
> using Firefox without incident for a while. From the commit note,
> I guess the video memory is being grabbed by a large page allocation
> improperly?


if the physical address of the video memory is less than the highest
physical address of normal memory, then it's being mapped by the
direct-map, yes.  that shouldn't cause a problem since nothing should be
referencing non-RAM addresses via the direct map, but there may be something
subtle going on.  openbsd and freebsd also have a direct map that includes
the gaps between RAM regions, and they apparently don't have these problems,
so something else that we're doing differently must be involved.

could you enable "options DEBUG_MEMLOAD" and "options PCI_CONFIG_DUMP"
and send me the boot output?  you may also need to increase MSGBUFSIZE.

-Chuck