5.3-RELEASE crashes during make buildworld (and other problems)

[Rick Updegrove]

Mark Kirkwood wrote:
>  I am wondering if cpu overheating could be a factor. In 4.x you are
>  building with gcc 2.95, whereas 5.3 uses 3.4 - the 3.x compiler
>  takes longer and works harder, which may be generating more heat (i.e
>  too much heat).
>
>  You can test this by installing the cpuburn port and running it for
>  10-20 minutes.

Thank you very much for the reply Mark.  I installed cpuburn but ran out 
of time that night to test it.
After some reading, I limited the RAM by adding the following to rc.conf

hw.physmem="512M"                # Limit physical memory. See loader(8)

Then I rebooted.  I did this because I do not want to wait for 1536M to
be written to disk after the inevitable crash.  Then I ran cpuburn
(actually burnK7) and "top" and monitored them.

*"start paste from top process"

last pid: 56346;  load averages:  1.00,  1.00,  1.13
                              up 0+01:28:13  19:59:17
31 processes:  2 running, 29 sleeping
CPU states: 99.2% user,  0.0% nice,  0.4% system,  0.4% interrupt,  0.0%
idle
Mem: 48M Active, 160M Inact, 69M Wired, 1848K Cache, 60M Buf, 214M Free
Swap: 3047M Total, 3047M Free

  PID USERNAME PRI NICE   SIZE    RES STATE    TIME   WCPU    CPU COMMAND
  607 root     131    0   136K    36K RUN     51:14 98.97% 98.97% burnK7

*"end paste from top process"

As you can see it went on for 51 minutes and my machine did not lock up
and the heat alarm did not go off.  Please note that I ran KDE and
portupgrade during this test with no problems at all.  Also note there is a
160 GIG drive in here that was undergoing a fsck -B which really slows 
down the system a lot.

Thanks again for the reply, but I do not suspect hardware per se.  The
reason I believe this is as I mentioned  this machine runs FreeBSD
4.11-STABLE and/or Win2K (all service packs) just fine.  On windoze I
just beat half-life 2 without ever crashing it.

On FreeBSD 4.11 I run make buildworld every few days without ever
crashing it.

The only thing I can think to do differently is comment
# hw.physmem="512M"                # Limit physical memory. See loader(8)
and try cpuburn again?  Any other ideas?

Rick

P.S.
After writing all this, I did manage to finally build 5.3-STABLE after a
few more tries at make buildworld, from wherever it failed.  Aside from
one lockup in KDE (no crashdump yet sorry) last night it has been ok
today.  I will however continue to test make buildworld and try to get a 
crashdump to post to the list because I would really like to know
what is really causing this instability.  Thanks again!