Re: diskless sparc locks up under memory pressure

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

On Sat, Nov 07, 2020 at 06:33:26PM +0300, Valery Ushakov wrote:
> I've upgraded my Krups (64MB RAM, diskless) to 9.99.75 as of Nov 6 and
> the machine is locking up at boot time in rc.d/fccache.  If I disable
> fccache in rc.conf it boots but then eventually locks up when
> makemandb is run.  The machine doesn't respond to pings, etc, but can
> enter ddb.  In all cases the ddb stacktrace goes through:
> 
> ...
> uvm_fault_internal
> mem_access_fault4m
> memfault_sun4m
> copyout
> 
> with the top part of the stack trace varying.
> 
> -uwe

do any threads (eg. the pagedaemon) still run when the machine locks up?
that's the stack trace of the pagedaemon thread?
when the machine is in this state, could you run "show uvmexp" in ddb,
then continue and wait for 10 seconds, then "show uvmexp" again?
then we can compare the counters from the two samples to see
what the pagedaemon is doing during this time.

-Chuck