Re: fifo panic (was: Panic when building the world under SMP kernel (HTT).)

>> Just to report that i always encountered a panic when building the world
>> using an SMP kernel for a CPU with HTT enable (in the BIOS) and the
>> sysctl machdep.hlt_logical_cpus set to 0.
>>
>> Just cvsup'ed (kernel built at Fri Sep 9 18:39:41 CEST 2005).
>> See the kernel trace and kernel configuration file attached, please.

> Do you have a crash dump for this crash, and a kernel with debugging
> symbols?  There have been occasional fifo panic reports from SMP boxes
> (especially >=4 CPUs doing builds), and I'd like to try to track it down,
> but based on prior experience, we'll need some amount of detailed
> debugging information to get much further.

(I should have say that this box follow the RELENG_6 branch.)

Yes, i have a kernel with debugging symbols.  Sadly, it seems that the
core file is unusable (maybe due to the "write_null" error on notebook
disk, see below):

/* From a serial console */
db> panic
panic: from debugger
cpuid = 0
Uptime: 22m7s
Dumping 1021 MB (2 chunks)
ad0: timeout waiting to issue command
ad0: error issueing WRITE_MUL command
  chunk 0: 1MB (159 pages)ad0: timeout waiting to issue command
ad0: error issueing WRITE_MUL command
 ... ok
  chunk 1: 1021MB (261360 pages) 1005 989 973 957 941 925 909 893 877 861
845 829 813 797 781 765 749 733 717 701 685 669 653 637 621 605 589 573
557 541 525 509 493 477 461 445 429 413 397 381 365 349 333 317 301 285
269 253 237 221 205 189 173 157 141 125 109 93 77 61 45 29 13 ... ok

/* After a reboot */
# cd /var/crash
# gzip -d vmcore.18.gz
# kgdb /usr/obj/usr/src/sys/BOBOCHE/kernel.debug vmcore.18
kgdb: cannot read IdlePTD

I think this timeout is a "side effect" of some energy saving mecanism
on the disk.  If someone can help me bypassing this timeout problem, i
may provide a crash dump ASAP (i will try to reproduce the panic sitting
near the machine to get a dump typing `panic' _just_ after the crash).

Thanks,

-- 
-jpeg.