kernel panics with RPCSEC_GSS

[Clinton Adams]

Hi,

On 8.2-RELEASE-p2, kernel occassionaly panics during relatively high
nfs usage (usually morning logins). Frequency of crashes have
decreased as we have reduced the number of clients, about twice a week
with 10 clients versus daily with 15.

Server is running nfsv4 with mit kerberos, clients are linux (ubuntu 10.04).

Backtraces from last 2 cores -

#1  0xffffffff805cbb5e in boot (howto=260)
    at /usr/src/sys/kern/kern_shutdown.c:419
#2  0xffffffff805cbf91 in panic (fmt=Variable "fmt" is not available.
) at /usr/src/sys/kern/kern_shutdown.c:592
#3  0xffffffff808d25c0 in trap_fatal (frame=0xc, eva=Variable "eva" is
not available.
)
    at /usr/src/sys/amd64/amd64/trap.c:783
#4  0xffffffff808d299f in trap_pfault (frame=0xffffff8096bb7790, usermode=0)
    at /usr/src/sys/amd64/amd64/trap.c:699
#5  0xffffffff808d2e7f in trap (frame=0xffffff8096bb7790)
    at /usr/src/sys/amd64/amd64/trap.c:449
#6  0xffffffff808baf74 in calltrap ()
    at /usr/src/sys/amd64/amd64/exception.S:224
#7  0xffffffff807db8d8 in svc_rpc_gss_forget_client (client=0x0)
    at /usr/src/sys/rpc/rpcsec_gss/svc_rpcsec_gss.c:616
#8  0xffffffff807dc1c3 in svc_rpc_gss (rqst=0xffffff005708c000,
    msg=0xffffff8096bb7b20) at /usr/src/sys/rpc/rpcsec_gss/svc_rpcsec_gss.c:642
#9  0xffffffff807d49d3 in svc_run_internal (pool=0xffffff003d03d600,
    ismaster=0) at /usr/src/sys/rpc/svc.c:837
#10 0xffffffff807d518b in svc_thread_start (arg=Variable "arg" is not available.
)
    at /usr/src/sys/rpc/svc.c:1200
#11 0xffffffff805a2798 in fork_exit (
    callout=0xffffffff807d5180 <svc_thread_start>, arg=0xffffff003d03d600,
    frame=0xffffff8096bb7c40) at /usr/src/sys/kern/kern_fork.c:845
#12 0xffffffff808bb43e in fork_trampoline ()
    at /usr/src/sys/amd64/amd64/exception.S:565


#1  0xffffffff805cbabe in boot (howto=260)
    at /usr/src/sys/kern/kern_shutdown.c:419
#2  0xffffffff805cbed3 in panic (fmt=0x0)
    at /usr/src/sys/kern/kern_shutdown.c:592
#3  0xffffffff808d239d in trap_fatal (frame=0xffffff0004c89460,
eva=Variable "eva" is not available.
)
    at /usr/src/sys/amd64/amd64/trap.c:783
#4  0xffffffff808d275f in trap_pfault (frame=0xffffff8096c0d790, usermode=0)
    at /usr/src/sys/amd64/amd64/trap.c:699
#5  0xffffffff808d2b5f in trap (frame=0xffffff8096c0d790)
    at /usr/src/sys/amd64/amd64/trap.c:449
#6  0xffffffff808bada4 in calltrap ()
    at /usr/src/sys/amd64/amd64/exception.S:224
#7  0xffffffff807db856 in svc_rpc_gss_forget_client (client=0xffffff001c015200)
    at atomic.h:158
#8  0xffffffff807dc0e3 in svc_rpc_gss (rqst=0xffffff0004a24000,
    msg=0xffffff8096c0db20) at /usr/src/sys/rpc/rpcsec_gss/svc_rpcsec_gss.c:642
#9  0xffffffff807d48f3 in svc_run_internal (pool=0xffffff0004ca6200,
    ismaster=0) at /usr/src/sys/rpc/svc.c:837
#10 0xffffffff807d50ab in svc_thread_start (arg=Variable "arg" is not available.
)
    at /usr/src/sys/rpc/svc.c:1200
#11 0xffffffff805a26f8 in fork_exit (
    callout=0xffffffff807d50a0 <svc_thread_start>, arg=0xffffff0004ca6200,
    frame=0xffffff8096c0dc40) at /usr/src/sys/kern/kern_fork.c:845
#12 0xffffffff808bb26e in fork_trampoline ()
    at /usr/src/sys/amd64/amd64/exception.S:565

Kernel is generic except for
device crypto
options KGSSAPI.

Ash /etc/make.conf
WITHOUT_X11=yes
KRB5_HOME=/usr/local
KRB5_IMPL=mit
# added by use.perl 2011-09-02 11:38:57
PERL_VERSION=5.10.1

I'm happy to provide any additional info.

Thanks for any help,
Clinton