(9.2) panic under disk load (gam_server / knlist_remove_kq)

[Patrick Lamaiziere]

9.2 PRERELEASE (today) / amd64

Hello,

I'm seeing a panic while trying to build a poudriere repository.

As far I can see it always happens when gam_server is started (ie xfce is
running) and under disk load (poudriere bulk build) :
(That is something new, the box was pretty stable)

the complete crash dump (core.0.txt) is here:
http://user.lamaiziere.net/patrick/panic_gam_server.txt

Fatal trap 12: page fault while in kernel mode
cpuid = 1; apic id = 02
fault virtual address   = 0x58
fault code              = supervisor read data, page not present
Unread portion of the kernel message buffer:

Fatal trap 12: page fault while in kernel mode
cpuid = 1; apic id = 02
fault virtual address   = 0x58
fault code              = supervisor read data, page not present
instruction pointer     = 0x20:0xffffffff808f1bf1
stack pointer           = 0x28:0xffffff8108e12a40
frame pointer           = 0x28:0xffffff8108e12a70
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         = 23557 (gam_server)
trap number             = 12
panic: page fault
cpuid = 1

...

#0  doadump (textdump=<value optimized out>) at pcpu.h:234
234     pcpu.h: No such file or directory.
        in pcpu.h
(kgdb) #0  doadump (textdump=<value optimized out>) at pcpu.h:234
#1  0xffffffff8092e4d6 in kern_reboot (howto=260)
    at /usr/src/sys/kern/kern_shutdown.c:449
#2  0xffffffff8092e9d7 in panic (fmt=0x1 <Address 0x1 out of bounds>)
    at /usr/src/sys/kern/kern_shutdown.c:637
#3  0xffffffff80d13030 in trap_fatal (frame=0xc, eva=<value optimized out>)
    at /usr/src/sys/amd64/amd64/trap.c:879
#4  0xffffffff80d13391 in trap_pfault (frame=0xffffff8108e12990, usermode=0)
    at /usr/src/sys/amd64/amd64/trap.c:795
#5  0xffffffff80d13944 in trap (frame=0xffffff8108e12990)
    at /usr/src/sys/amd64/amd64/trap.c:463
#6  0xffffffff80cfcc73 in calltrap ()
    at /usr/src/sys/amd64/amd64/exception.S:232
#7  0xffffffff808f1bf1 in knlist_remove_kq (knl=0x30, kn=0xfffffe003b70b280, 
    knlislocked=0, kqislocked=0) at /usr/src/sys/kern/kern_event.c:1847
#8  0xffffffff808f4a5b in knote_fdclose (td=0xfffffe0009a34490, fd=9924)
    at /usr/src/sys/kern/kern_event.c:2065
#9  0xffffffff808ea573 in kern_close (td=0xfffffe0009a34490, fd=9924)
    at /usr/src/sys/kern/kern_descrip.c:1250
#10 0xffffffff80d127da in amd64_syscall (td=0xfffffe0009a34490, traced=0)
    at subr_syscall.c:135
#11 0xffffffff80cfcf57 in Xfast_syscall ()
    at /usr/src/sys/amd64/amd64/exception.S:391
#12 0x00000008019e9a9c in ?? ()
Previous frame inner to this frame (corrupt stack?)
(kgdb) 

Thanks, regards