repeatable crash with 5.4-RELEASE and PAE

[Brendan White]

We're having crash under load problems using freebsd 5.4-release  
(i386) and PAE kernel.

Machine:
Dual Xeon 3.6 Dell Poweredge 2850
8 gigs of ram
16 gigs of swap
amr raid

The machine will reliably crash under load within an hour or so.
"under load" involves large network transfers being processed by cpu  
and memory intensive processes.

i cant get a crash dump (when it starts dumping, it will stop part  
way thru displaying memory increments.)

I have gotten it to spit out a trace from KDB, which i've copied out  
below.
(i had to do it from a screenshot/by hand- i checked it twice, but if  
things dont make sence, there may be a typo)

kernel config included below the trace.
We've tried turning off hyperthreading.  The problem persists.
We've tried turning off PAE (which brings us from 8 gigs to 3).  The  
problem goes away.
This is obviously not the optimal solution.


---
kdb_enter(c05a1e33) at kdb_enter+0x2b
panic(c05a0a51,fffffffe,c05a0a3b,cb65ed80,fffffffe) at panic+0x127
lockmgr(cbadb7e4,6,cbadb738,0,f1b93a0c) at lockmgr+0x421
vop_stdunlock(f1b93a3c,f1b93a18,c038320f,f1b93a3c,f1b93a59) at  
vop_stdunlock+0x1f
vop_defaultop(f1b93a3c,f1b93a58,c038379c,f1b93a3c,1000) at  
vop_defaultop+0x13
spec_vnoperate(f1b93a3c,1000,7f010000,cba4e100,f1b93aa4) at  
spec_vnoperate+0x13
spec_write(f1b93a84,f1b93ad0,c04fce99,f1b93a84,cb65ed80) at spec_write 
+0x64
spec_vnoperate(f1b93a84) at spec_vnoperate+0x13
vnode_pager_generic_putpages(cbadb738,f1b93be0,1000,0,f1b93b60) at  
vnode_pager_generic_putpages+0x221
vop_stdputpages 
(f1b93b18,f1b93b18,f1b93b04,c038320f,f1b93b18,f1b93b44) at  
vop_stdputpages+0x1a
vop_defaultop(f1b93b18,f1b93b44,c04fcc36,f1b93b18,1000) at  
vop_defaultop+0x13
spec_vnoperate(f1b93b18) at spec_vnoperate+0x13
vnode_pager_putpages(cbb53ad4,f1b93be0,1,0,f1b93b60) at  
vnode_pager_putpages+0xba
vm_pageout_flush(f1b93be0,1,0,cbd7a600,f1b93bb8) at vm_pageout_flush 
+0xcb
vm_pageout_clean(c4254e4c) at vm_pageout_clean+0x2a1
vm_pageout_scan(0) at vm_pageout_scan+0x706
vm_pageout(0,f1b93d38) at vm_pageout+0x312
fork_exit(c04f5e1c,0,f1b93d38) at fork_exit+0x75
fork_trampoline() at fork_trampoline+0x8
--- trap 0x1, eip=0, esp = 0xf1b93d6c, ebp = 0 ---



kernel config:

include GENERIC
ident           PAE-GENERIC
options         KDB_TRACE
options         KDB
options         DDB
makeoptions     DEBUG=-g
options         SMP
options         COMPAT_LINUX
device          acpi
makeoptions     NO_MODULES=yes
nodevice        ahb
nodevice        amd
nodevice        sym
nodevice        trm
nodevice        adv
nodevice        adw
nodevice        aha
nodevice        aic
nodevice        bt
nodevice        ncv
nodevice        nsp
nodevice        stg
nodevice        asr
nodevice        dpt
nodevice        iir
nodevice        mly
nodevice        ida
nodevice        mlx
nodevice        pst
nodevice        agp
nodevice        de
nodevice        txp
nodevice        vx
nodevice        dc
nodevice        pcn
nodevice        rl
nodevice        sf
nodevice        sis
nodevice        ste
nodevice        tl
nodevice        tx
nodevice        vr
nodevice        wb
nodevice        cs
nodevice        ed
nodevice        ex
nodevice        ep
nodevice        fe
nodevice        ie
nodevice        lnc
nodevice        sn
nodevice        xe
nodevice        wlan
nodevice        an
nodevice        awi
nodevice        wi
nodevice        uhci
nodevice        ohci
nodevice        ehci
nodevice        usb
nodevice        ugen
nodevice        uhid
nodevice        ukbd
nodevice        ulpt
nodevice        umass
nodevice        ums
nodevice        urio
nodevice        uscanner
nodevice        aue
nodevice        axe
nodevice        cdce
nodevice        cue
nodevice        kue
nodevice        rue