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

> 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


I'll apply the patch this weekend.

If I get time I'll also try to reproduce your panic.


Thanks,
Kip









>
> 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.
>



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