./qemu-system-sparc64 -M niagara -L /git/md/bin/tlb_fix/2048 -nographic -m 2048 -drive if=pflash,readonly=on,file=/zroot/iso/osol-dev-134-ai-sparc.iso
cpu Probing I/O buses


Sun Fire T2000, No Keyboard
Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
OpenBoot 4.20.0, 2048 MB memory available, Serial #1122867.
[mo23723 obp4.20.0 #0]
Ethernet address 0:80:3:de:ad:3, Host ID: 80112233.



ok boot -kdv
Boot device: /virtual-devices/disk@0  File and args: -kdv
hsfs-file-system
Loading: /platform/sun4v/boot_archive
ramdisk-root ufs-file-system
Loading: /platform/sun4v/kernel/sparcv9/unix
module /platform/sun4v/kernel/sparcv9/unix: text at [0x1000000, 0x10d9cef] data at 0x1800000
module /platform/sun4v/kernel/sparcv9/genunix: text at [0x10d9cf0, 0x12d4d17] data at 0x18d93c0
module /platform/sun4v/kernel/misc/sparcv9/platmod: text at [0x12d4d18, 0x12d4d1f] data at 0x192f670
module /platform/sun4v/kernel/cpu/sparcv9/SUNW,UltraSPARC-T1: text at [0x12d4d20, 0x12d8e77] data at 0x192fd40
Loading kmdb...
module /platform/sun4v/kernel/misc/sparcv9/kmdbmod: text at [0x12d8e80, 0x13553bf] data at 0x19487c0
module /kernel/misc/sparcv9/ctf: text at [0x13553c0, 0x135cda7] data at 0x1965f30
-
Welcome to kmdb
kmdb: unable to determine terminal type: assuming `vt100'
Loaded modules: [ unix krtld genunix ]
[0]> :c
(hard hang; no further console output. Broke in via serial break
(Ctrl-A b in the QEMU -nographic console) instead of just recording a
black-box hang.)
kmdb: single-step stop on miscellaneous trap
kmdb: target stopped at:
alloc_page_freelists+0x54:      stx       %i0, [%l6 + %l7]
[0]> :c
(broke in a second time to confirm)
kmdb: single-step stop on miscellaneous trap
kmdb: target stopped at:
alloc_page_freelists+0x54:      stx       %i0, [%l6 + %l7]

CONFIRMED (via serial-break, same technique used on the Solaris 10u10
hang): stuck inside alloc_page_freelists, same function and same class
of stuck store instruction as tlb_fix-2048__sol-10-u10.txt (there at
+0x44, here at +0x54 -- close but not identical offset, still worth
noting). Two independent breaks landed on the identical PC both times.
This means the alloc_page_freelists hang is NOT specific to Solaris
10u10 -- it reproduces across multiple OS images on tlb_fix/2048,
strengthening the theory that this is a systemic bug in this MD/hv-config
build specific to 2048M (not seen on tlb_fix/1024), rather than
something particular to any one guest OS. Supersedes the earlier note
on this file claiming the hang was "not related to the memsize bug" --
that conclusion was made before this trace and needs revisiting.