Just had a PWS 433au NFS server hang twice while under
	moderate load.  It has been running fine for a while, but
	the load level increased after friday.

	Common activity in both cases was recompiling some software.

	Machine was non responsive, ddb indicated:

	    --- interrupt [...]
	    pmap_changebit()
	    pmap_emulate_reference()
	    trap()
	    XentMM()
	    ---- memory management fault
	    memcpy()
	    copyout()
	    sys_select()
	    sysacll_plain()
	    XentSys()

	A reboot from ddb looped on

	    pciide0:0:0 lost interrupt.
	    ...

	Power switch on front required.

	Console indicated some tlp transmit underruns. Last one was around
	an hour before failure, setting 'threshold: 160/1024'. One hang
	happpend with built in tulip in use, second with separate card.

	Machine has IDE drive plus advansys (adw) SCSI with disk and tape,
	both disks in active use.

	Anyone have any ideas?

NetBSD 1.6_BETA5 (_TACHYON_) #0: Mon Aug  5 17:23:40 BST 2002
    abs@tachyon:/files/netbsd/1.6/sys/arch/alpha/compile/_TACHYON_
Digital Personal WorkStation 433au, 432MHz, s/n
8192 byte page size, 1 processor.
total memory = 128 MB
(1992 KB reserved for PROM, 126 MB used by NetBSD)
avail memory = 113 MB
using 819 buffers containing 6552 KB of memory
mainbus0 (root)
cpu0 at mainbus0: ID 0 (primary), 21164A-0
cpu0: Architecture extensions: 1<BWX>
cia0 at mainbus0: DECchip 2117x Core Logic Chipset (Pyxis), pass 1
cia0: extended capabilities: 1<BWEN>
cia0: using BWX for PCI config access
cia0: WARNING: Pyxis pass 1 DMA bug; no bets...
pci0 at cia0 bus 0
pci0: i/o space, memory space enabled
tlp0 at pci0 dev 3 function 0: DECchip 21143 Ethernet, pass 3.0
tlp0: interrupting at dec 550 irq 0
tlp0: DEC , Ethernet address 00:00:f8:75:5c:e3
nsphy0 at tlp0 phy 5: DP83840 10/100 media interface, rev. 1
nsphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
tlp0: 10baseT, 10baseT-FDX, 10base2, 10base5
pciide0 at pci0 dev 4 function 0: CMD Technology PCI0646 (rev. 0x01)
pciide0: bus-master DMA support present
pciide0: primary channel wired to compatibility mode
wd0 at pciide0 channel 0 drive 0: <Maxtor 91361U3>
wd0: drive supports 16-sector PIO transfers, LBA addressing
wd0: 12982 MB, 16383 cyl, 16 head, 63 sec, 512 bytes/sect x 26588016 sectors
wd0: 32-bit data port
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 4 (Ultra/66)
pciide0: primary channel interrupting at isa irq 14
wd0(pciide0:0:0): using PIO mode 4, DMA mode 2 (using DMA data transfers)
pciide0: secondary channel wired to compatibility mode
pciide0: secondary channel ignored (disabled)
sio0 at pci0 dev 7 function 0: Intel 82378ZB System I/O (SIO) (rev. 0x43)
ppb0 at pci0 dev 20 function 0: Digital Equipment DECchip 21052 PCI-PCI Bridge (rev. 0x02)
pci1 at ppb0 bus 1
pci1: i/o space, memory space enabled
vga0 at pci1 dev 8 function 0: Cirrus Logic CL-GD5446 (rev. 0x45)
wsdisplay0 at vga0 (kbdmux ignored): console (80x25, vt100 emulation)
tlp1 at pci1 dev 9 function 0: DECchip 21140A Ethernet, pass 2.2
tlp1: interrupting at dec 550 irq 16
tlp1: Ethernet address 00:80:c8:27:02:c2
lxtphy0 at tlp1 phy 0: LXT970 10/100 media interface, rev. 1
lxtphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
adw0 at pci1 dev 10 function 0: AdvanSys ASB-3940U2W-00 SCSI adapter
adw0: interrupting at dec 550 irq 20
scsibus0 at adw0: 16 targets, 7 luns per target
isa0 at sio0
com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
pckbc0 at isa0 port 0x60-0x64
pckbd0 at pckbc0 (kbd slot)
pckbc0: using irq 1 for kbd slot
wskbd0 at pckbd0 (mux ignored): console keyboard, using wsdisplay0
pcppi0 at isa0 port 0x61
midi0 at pcppi0: PC speaker
spkr0 at pcppi0
isabeep0 at pcppi0
fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2
mcclock0 at isa0 port 0x70-0x71: mc146818 or compatible
scsibus0: waiting 2 seconds for devices to settle...
adw0: target 0 using 8-bits wide, asynchronous transfers
adw0: target 0 wide/sync renegotiation pending before next command.
sd0 at scsibus0 target 0 lun 0: <IBM, DNES-309170W, SA30> SCSI3 0/direct fixed
sd0: 8748 MB, 11474 cyl, 5 head, 312 sec, 512 bytes/sect x 17916240 sectors
adw0: target 6 using 8-bits wide, asynchronous transfers
adw0: target 6 wide/sync renegotiation pending before next command.
st0 at scsibus0 target 6 lun 0: <QUANTUM, DLT7000, 1624> SCSI2 1/sequential removable
st0: density code 27, variable blocks, write-enabled
Kernelized RAIDframe activated
root on wd0a dumps on wd0b
root file system type: ffs


-- 
		David/absolute		abs@formula1.com