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

[gary%duzan.org@localhost]

=> On Mon, 2 Jan 2012 09:13:37 -0800
=> Chuck Silvers <chuq%chuq.com@localhost> wrote:
=>
=>> 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.
=>
=> Just curious: is there a PR filed for this issue, and/or is it known to
=> be fixed?

   The last time I tried to recreate this problem I ran into other
problems before I could trigger this one. It did seem harder to
trigger, at least. I have a fresh build at home that I will try to
break sometime this weekend. I'm not aware of a PR.

                                       Gary Duzan