I have a recurring hang on FreeBSD 7.1 roughly-RC1 (releng_7_1 checkout
as of 2008-12-08) on a dual-CPU hyperthreaded Xeon i386. I've dropped
into the kernel debugger on the VGA console and transcribed the
following information (if I omit anything critical, let me know -- the
machine is still sitting at the debugger prompt) :
> where
pid 20 tid 100018 td 0xc45008c0
kdb_enter_why
scgetc
sckdbevent
kdbmux_intr
kdbmux_kdb_intr
taskqueue_run
taskqueue_swi_giant_run
ithread_loop
fork_exit(c063cce0, c44ac590, e4a36d38) at 0xc063a624 = fork_exit+0x94
fork_trampoline() at 0xc07e41a0 = fork_trampoline+0x8
> show allpcpu
cpuid 0 in idle
cpuid 1: proc 23457
cpuid 2: idle
cpuid 3: swi6 proc 20
> show alllocks
pid 23708 vmstat: shared sx allproc, exclusive sx sysctl
pid 23675 php: exclusive sx user map
pid 4630 tcsh: shared sx proctree
pid 3838 sshd: shared sx proctree
pid 2139 icapd: shared sx proctree
pid 1425 postgres: shared sx proctree
pid 20 swi6: exclusive sleep mtx Giant
> show sleepchain 23708
thread 100050 (pid 23708, vmstat) blocked on sx "user map" XLOCK
thread 100056 (pid 23675, initial thread) is on a run queue
> show sleepchain 4630
thread 100093 (pid 4630, tcsh) blocked on sx "allproc" SLOCK (count 1)
> show sleepchain 3838
thread 100065 (pid 3838, sshd) blocked on sx "allproc" SLOCK (count 1)
> show sleepchain 2139
thread 100136 (pid 2139, icapd) blocked on sx "allproc" SLOCK (count
1)
> show sleepchain 1425
thread 100140 (pid 1425, initial thread) blocked on sx "allproc" SLOCK
(count 1)
> where 23708
...
syscall 202 sysctl
> where 23675
...
trap 0xc
> where 4630
...
syscall 66 vfork
> where 3838
...
syscall 2 fork
> where 2139
...
syscall 2 fork
> where 1425
...
syscall 2 fork
Kernel configuration file:
ident PALISADE-DEBUG
options MUTEX_DEBUG
options WITNESS
options WITNESS_KDB
options WITNESS_SKIPSPIN
options KDB
options KDB_TRACE
options DDB
options DDB_NUMSYM
options GDB
cpu I686_CPU
# To statically compile in device wiring instead of /boot/device.hints
#hints "GENERIC.hints" # Default places to look for
devices.
makeoptions DEBUG=-g # Build kernel with gdb(1) debug
symbols
options SCHED_ULE # ULE scheduler
options PREEMPTION # Enable kernel thread preemption
options INET # InterNETworking
#options INET6 # IPv6 communications protocols
#options SCTP # Stream Control Transmission
Protocol
options FFS # Berkeley Fast Filesystem
options SOFTUPDATES # Enable FFS soft updates support
options UFS_ACL # Support for access control lists
options UFS_DIRHASH # Improve performance on big
directories
options UFS_GJOURNAL # Enable gjournal-based UFS
journaling
options MD_ROOT # MD is a potential root device
options NFSCLIENT # Network Filesystem Client
options NFSSERVER # Network Filesystem Server
options NFS_ROOT # NFS usable as /, requires
NFSCLIENT
options MSDOSFS # MSDOS Filesystem
options CD9660 # ISO 9660 Filesystem
options PROCFS # Process filesystem (requires
PSEUDOFS)
options PSEUDOFS # Pseudo-filesystem framework
options GEOM_PART_GPT # GUID Partition Tables.
options GEOM_LABEL # Provides labelization
options COMPAT_43TTY # BSD 4.3 TTY compat [KEEP THIS!]
options COMPAT_FREEBSD4 # Compatible with FreeBSD4
options COMPAT_FREEBSD5 # Compatible with FreeBSD5
options COMPAT_FREEBSD6 # Compatible with FreeBSD6
options SCSI_DELAY=5000 # Delay (in ms) before probing SCSI
options KTRACE # ktrace(1) support
options SYSVSHM # SYSV-style shared memory
options SYSVMSG # SYSV-style message queues
options SYSVSEM # SYSV-style semaphores
options SHMMAXPGS=4096 # max shared mem pages (4k on i386)
options SHMSEG=256 # max shared mem segments per
process
options SEMMNI=256 # number of semaphore identifiers
options SEMMNS=512 # number of semaphores
options SEMMNU=256 # number of undo structures
options SEMMAP=256 # entries in semaphore map
options _KPOSIX_PRIORITY_SCHEDULING # POSIX P1003_1B real-time
extensions
options KBD_INSTALL_CDEV # install a CDEV entry in /dev
options ADAPTIVE_GIANT # Giant mutex is adaptive.
options STOP_NMI # Stop CPUS using NMI instead of IPI
options AUDIT # Security event auditing
options DEVICE_POLLING
options MAXDSIZ=(1024UL*1024*1024) # See /sys/conf/NOTES for info
options IPFIREWALL #firewall
options IPFIREWALL_VERBOSE #enable logging to syslogd(8)
options IPFIREWALL_VERBOSE_LIMIT=100 #limit verbosity
options IPFIREWALL_FORWARD #packet destination changes
options DUMMYNET #Packet shaping
# To make an SMP kernel, the next two are needed
options SMP # Symmetric MultiProcessor Kernel
device apic # I/O APIC
# CPU frequency control
device cpufreq
# Bus support.
device eisa
device pci
# Floppy drives
device fdc
# ATA and ATAPI devices
device ata
device atadisk # ATA disk drives
device ataraid # ATA RAID drives
device atapicd # ATAPI CDROM drives
device atapifd # ATAPI floppy drives
device atapist # ATAPI tape drives
options ATA_STATIC_ID # Static device numbering
# SCSI Controllers
#device ahb # EISA AHA1742 family
device ahc # AHA2940 and onboard AIC7xxx devices
options AHC_REG_PRETTY_PRINT # Print register bitfields in debug
# output. Adds ~128k to driver.
device ahd # AHA39320/29320 and onboard AIC79xx devices
options AHD_REG_PRETTY_PRINT # Print register bitfields in debug
# output. Adds ~215k to driver.
#device amd # AMD 53C974 (Tekram DC-390(T))
#device hptiop # Highpoint RocketRaid 3xxx series
#device isp # Qlogic family
#device ispfw # Firmware for QLogic HBAs- normally a
module
device mpt # LSI-Logic MPT-Fusion
#device ncr # NCR/Symbios Logic
#device sym # NCR/Symbios Logic (newer chipsets +
those of `ncr')
#device trm # Tekram DC395U/UW/F DC315U adapters
#device adv # Advansys SCSI adapters
#device adw # Advansys wide SCSI adapters
#device aha # Adaptec 154x SCSI adapters
#device aic # Adaptec 15[012]x SCSI adapters,
AIC-6[23]60.
#device bt # Buslogic/Mylex MultiMaster SCSI adapters
#device ncv # NCR 53C500
#device nsp # Workbit Ninja SCSI-3
#device stg # TMC 18C30/18C50
# SCSI peripherals
device scbus # SCSI bus (required for SCSI)
device ch # SCSI media changers
device da # Direct Access (disks)
device sa # Sequential Access (tape etc)
device cd # CD
device pass # Passthrough device (direct SCSI access)
device ses # SCSI Environmental Services (and SAF-TE)
# RAID controllers interfaced to the SCSI subsystem
#device amr # AMI MegaRAID
#device arcmsr # Areca SATA II RAID
#device asr # DPT SmartRAID V, VI and Adaptec SCSI RAID
#device ciss # Compaq Smart RAID 5*
#device dpt # DPT Smartcache III, IV - See NOTES for
options
#device hptmv # Highpoint RocketRAID 182x
#device hptrr # Highpoint RocketRAID 17xx, 22xx, 23xx,
25xx
#device iir # Intel Integrated RAID
#device ips # IBM (Adaptec) ServeRAID
#device mly # Mylex AcceleRAID/eXtremeRAID
device twa # 3ware 9000 series PATA/SATA RAID
# RAID controllers
device aac # Adaptec FSA RAID
#device aacp # SCSI passthrough for aac (requires CAM)
#device ida # Compaq Smart RAID
device mfi # LSI MegaRAID SAS
#device mlx # Mylex DAC960 family
#device pst # Promise Supertrak SX6000
device twe # 3ware ATA RAID
# atkbdc0 controls both the keyboard and the PS/2 mouse
device atkbdc # AT keyboard controller
device atkbd # AT keyboard
device psm # PS/2 mouse
device kbdmux # keyboard multiplexer
device vga # VGA video card driver
device splash # Splash screen and screen saver support
# syscons is the default console driver, resembling an SCO console
device sc
device agp # support several AGP chipsets
# Power management support (see NOTES for more options)
#device apm
# Add suspend/resume support for the i8254.
device pmtimer
# PCCARD (PCMCIA) support
# PCMCIA and cardbus bridge support
device cbb # cardbus (yenta) bridge
device pccard # PC Card (16-bit) bus
device cardbus # CardBus (32-bit) bus
# Serial (COM) ports
device sio # 8250, 16[45]50 based serial ports
device uart # Generic UART driver
# Parallel port
device ppc
device ppbus # Parallel port bus (required)
device lpt # Printer
device plip # TCP/IP over parallel
device ppi # Parallel port interface device
#device vpo # Requires scbus and da
# If you've got a "dumb" serial or parallel PCI card that is
# supported by the puc(4) glue driver, uncomment the following
# line to enable it (connects to sio, uart and/or ppc drivers):
#device puc
# PCI Ethernet NICs.
device de # DEC/Intel DC21x4x (``Tulip'')
device em # Intel PRO/1000 adapter Gigabit
Ethernet Card
device ixgb # Intel PRO/10GbE Ethernet Card
device le # AMD Am7900 LANCE and Am79C9xx PCnet
device txp # 3Com 3cR990 (``Typhoon'')
device vx # 3Com 3c590, 3c595 (``Vortex'')
# PCI Ethernet NICs that use the common MII bus controller code.
# NOTE: Be sure to keep the 'device miibus' line in order to use these
NICs!
device miibus # MII bus support
device bce # Broadcom BCM5706/BCM5708 Gigabit Ethernet
device bfe # Broadcom BCM440x 10/100 Ethernet
device bge # Broadcom BCM570xx Gigabit Ethernet
device dc # DEC/Intel 21143 and various workalikes
device fxp # Intel EtherExpress PRO/100B (82557, 82558)
device lge # Level 1 LXT1001 gigabit Ethernet
device msk # Marvell/SysKonnect Yukon II Gigabit
Ethernet
device nfe # nVidia nForce MCP on-board Ethernet
device nge # NatSemi DP83820 gigabit Ethernet
#device nve # nVidia nForce MCP on-board Ethernet
Networking
#device pcn # AMD Am79C97x PCI 10/100(precedence
over 'lnc')
device re # RealTek 8139C+/8169/8169S/8110S
device rl # RealTek 8129/8139
#device sf # Adaptec AIC-6915 (``Starfire'')
device sis # Silicon Integrated Systems SiS 900/SiS
7016
device sk # SysKonnect SK-984x & SK-982x gigabit
Ethernet
#device ste # Sundance ST201 (D-Link DFE-550TX)
#device stge # Sundance/Tamarack TC9021 gigabit Ethernet
#device ti # Alteon Networks Tigon I/II gigabit
Ethernet
#device tl # Texas Instruments ThunderLAN
#device tx # SMC EtherPower II (83c170 ``EPIC'')
device vge # VIA VT612x gigabit Ethernet
#device vr # VIA Rhine, Rhine II
#device wb # Winbond W89C840F
device xl # 3Com 3c90x (``Boomerang'',
``Cyclone'')
# ISA Ethernet NICs. pccard NICs included.
#device cs # Crystal Semiconductor CS89x0 NIC
# 'device ed' requires 'device miibus'
#device ed # NE[12]000, SMC Ultra, 3c503, DS8390 cards
#device ex # Intel EtherExpress Pro/10 and Pro/10+
#device ep # Etherlink III based cards
#device fe # Fujitsu MB8696x based cards
#device ie # EtherExpress 8/16, 3C507, StarLAN 10 etc.
#device lnc # NE2100, NE32-VL Lance Ethernet cards
#device sn # SMC's 9000 series of Ethernet chips
#device xe # Xircom pccard Ethernet
# Wireless NIC cards
#device wlan # 802.11 support
#device wlan_wep # 802.11 WEP support
#device wlan_ccmp # 802.11 CCMP support
#device wlan_tkip # 802.11 TKIP support
#device wlan_amrr # AMRR transmit rate control algorithm
#device wlan_scan_ap # 802.11 AP mode scanning
#device wlan_scan_sta # 802.11 STA mode scanning
#device an # Aironet 4500/4800 802.11 wireless NICs.
#device ath # Atheros pci/cardbus NIC's
#device ath_hal # Atheros HAL (Hardware Access Layer)
#device ath_rate_sample # SampleRate tx rate control for ath
#device awi # BayStack 660 and others
#device ral # Ralink Technology RT2500 wireless NICs.
#device wi # WaveLAN/Intersil/Symbol 802.11
wireless NICs.
#device wl # Older non 802.11 Wavelan wireless NIC.
# Pseudo devices.
device loop # Network loopback
device random # Entropy device
device ether # Ethernet support
#device sl # Kernel SLIP
#device ppp # Kernel PPP
device tun # Packet tunnel.
device pty # Pseudo-ttys (telnet etc)
device md # Memory "disks"
#device gif # IPv6 and IPv4 tunneling
#device faith # IPv6-to-IPv4 relaying (translation)
device firmware # firmware assist module
# The `bpf' device enables the Berkeley Packet Filter.
# Be aware of the administrative consequences of enabling this!
# Note that 'bpf' is required for DHCP.
device bpf # Berkeley packet filter
# USB support
device uhci # UHCI PCI->USB interface
device ohci # OHCI PCI->USB interface
device ehci # EHCI PCI->USB interface (USB 2.0)
device usb # USB Bus (required)
#device udbp # USB Double Bulk Pipe devices
device ugen # Generic
device uhid # "Human Interface Devices"
device ukbd # Keyboard
device ulpt # Printer
#device umass # Disks/Mass storage - Requires scbus and da
device ums # Mouse
#device ural # Ralink Technology RT2500USB wireless NICs
#device rum # Ralink Technology RT2501USB wireless NICs
#device urio # Diamond Rio 500 MP3 player
#device uscanner # Scanners
# USB Ethernet, requires miibus
device aue # ADMtek USB Ethernet
device axe # ASIX Electronics USB Ethernet
device cdce # Generic USB over Ethernet
device cue # CATC USB Ethernet
device kue # Kawasaki LSI USB Ethernet
device rue # RealTek RTL8150 USB Ethernet
# FireWire support
#device firewire # FireWire bus code
#device sbp # SCSI over FireWire (Requires scbus and da)
#device fwe # Ethernet over FireWire (non-standard!)
#device fwip # IP over FireWire (RFC 2734,3146)
#device dcons # Dumb console driver
#device dcons_crom # Configuration ROM for dcons