Re: Fatal trap 12: page fault panic with recent kernel with ZFS

On May 19, 2009, at 03:15 AM, Kip Macy wrote:

>
> Please update to r192360 and let me know if that helps.
>
>
> Thanks,
> Kip

Hey, I (not the OP) am still having trouble with this. The panics  
appear to be gone since I set arc_min to 30M and arc_max to 100M,  
though (2GB RAM).
I get/got them during a full zfs send -R | zfs recv -Fvd of a ~3.3GB  
pool. The only modification I've done to the source tree is the  
libzfs_sendrecv patch here:
http://lists.freebsd.org/pipermail/freebsd-current/2009-May/006814.html

FreeBSD chaos.exscape.org 8.0-CURRENT FreeBSD 8.0-CURRENT #1: Wed May  
20 21:19:29 CEST 2009     root_at_chaos.exscape.org:/usr/obj/usr/src/sys/ 
DTRACE  amd64
(GENERIC + the 3 DTrace lines added)

Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address	= 0x0
fault code		= supervisor write data, page not present
instruction pointer	= 0x20:0xffffffff8085e89a
stack pointer	        = 0x28:0xffffff803ea4e4d0
frame pointer	        = 0x28:0xffffff803ea4e590
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 1281 (zfs)

vmstat -s from core.txt shows 388955 pages wired down - I take it  
that's 388955*4 kiB or almost 1.5GB out of 2GB. 110685 pages are still  
free, if that's relevant (I'm not sure why the crash occurs, but I  
guess it might be).

Backtrace:
#0  doadump () at pcpu.h:223
223	pcpu.h: No such file or directory.
	in pcpu.h
(kgdb) #0  doadump () at pcpu.h:223
#1  0xffffffff80576089 in boot (howto=260)
     at /usr/src/sys/kern/kern_shutdown.c:420
#2  0xffffffff805764dc in panic (fmt=Variable "fmt" is not available.
)
     at /usr/src/sys/kern/kern_shutdown.c:576
#3  0xffffffff801d5a97 in db_panic (addr=Variable "addr" is not  
available.
)
     at /usr/src/sys/ddb/db_command.c:478
#4  0xffffffff801d5ea1 in db_command (last_cmdp=0xffffffff80bd7c20,  
cmd_table=Variable "cmd_table" is not available.

) at /usr/src/sys/ddb/db_command.c:445
#5  0xffffffff801d60f0 in db_command_loop ()
     at /usr/src/sys/ddb/db_command.c:498
#6  0xffffffff801d8089 in db_trap (type=Variable "type" is not  
available.
) at /usr/src/sys/ddb/db_main.c:229
#7  0xffffffff805a6bb5 in kdb_trap (type=12, code=0,  
tf=0xffffff803ea4e420)
     at /usr/src/sys/kern/subr_kdb.c:534
#8  0xffffffff808603bd in trap_fatal (frame=0xffffff803ea4e420,  
eva=Variable "eva" is not available.
)
     at /usr/src/sys/amd64/amd64/trap.c:847
#9  0xffffffff80860794 in trap_pfault (frame=0xffffff803ea4e420,  
usermode=0)
     at /usr/src/sys/amd64/amd64/trap.c:768
#10 0xffffffff80861283 in trap (frame=0xffffff803ea4e420)
     at /usr/src/sys/amd64/amd64/trap.c:494
#11 0xffffffff8083ae57 in calltrap ()
     at /usr/src/sys/amd64/amd64/exception.S:223
#12 0xffffffff8085e89a in bzero () at /usr/src/sys/amd64/amd64/ 
support.S:64
#13 0xffffffff80e8aab1 in dbuf_read () from /boot/kernel/zfs.ko
#14 0xffffffff80e8a12e in dmu_buf_rele () from /boot/kernel/zfs.ko
#15 0xffffff0002e34460 in ?? ()
#16 0x0000000000000000 in ?? ()
#17 0x0000000000000000 in ?? ()
#18 0x000000003ea4e570 in ?? ()
#19 0xffffff003533c2d0 in ?? ()
#20 0xffffff803ea4e588 in ?? ()
#21 0xffffff8004619240 in ?? ()
#22 0xffffff00415591c0 in ?? ()
#23 0x0000000000000000 in ?? ()
#24 0x0000000000000000 in ?? ()
#25 0x000000044153f300 in ?? ()
#26 0x0000000000000000 in ?? ()
#27 0xffffff0002e34460 in ?? ()
#28 0x0000000000000005 in ?? ()
#29 0xffffff004153f300 in ?? ()
#30 0x0000000000000000 in ?? ()
#31 0x000000000000da01 in ?? ()
#32 0xffffff803ea4e5c0 in ?? ()
#33 0xffffffff80e963ea in dmu_tx_check_ioerr () from /boot/kernel/zfs.ko

Regards,
Thomas

PS. I have the full core.txt if it'd help. DS.