strange load problem on freebsd 7.0 amd64

[skynet_tech]

System has dual Xeon quadracore, totally 8 CPU and 16 GB ram.
Problem: load average periodically is somewhere 20-30, and server is freezing. But in same time, only 1cpu is used. Running processes is many small fastcgi/php-cgi, so there is not one resource hungry process.


from top:

last pid: 99483;  load averages: 23.82, 17.13, 14.08    up 6+19:09:32  16:22:11
913 processes: 2 running, 910 sleeping, 1 zombie
CPU states:  9.8% user,  0.0% nice,  8.0% system,  0.4% interrupt, 81.8% idle
Mem: 3006M Active, 10G Inact, 689M Wired, 476M Cache, 214M Buf, 859M Free
Swap: 4096M Total, 12K Used, 4096M Free

suggestions?

[graudeejs]

did you compile your kernel with SMP?
show your kernel config
show output of

uname -a

[skynet_tech]

cpu		HAMMER
ident	 	SUN	

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_IA32		# Compatible with i386 binaries
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 	_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

# Make an SMP-capable kernel by default
options 	SMP			# Symmetric MultiProcessor Kernel

options		QUOTA

# CPU frequency control
device		cpufreq

# Bus support.
device		acpi
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		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		aic		# Adaptec 15[012]x SCSI adapters, AIC-6[23]60.
device		bt		# Buslogic/Mylex MultiMaster SCSI adapters


# SCSI peripherals
device		scbus		# SCSI bus (required for SCSI)
device		ch		# SCSI media changers
device		da		# Direct Access (disks)
device		cd		# CD
device		pass		# Passthrough device (direct SCSI access)
device		ses		# SCSI Environmental Services (and SAF-TE)

# 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


# Serial (COM) ports
device		sio		# 8250, 16[45]50 based serial ports
device		uart		# Generic UART driver

# PCI Ethernet NICs.
device		em		# Intel PRO/1000 Gigabit Ethernet Family

# 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

I got load average around 0.5, and top show something like this

1021 processes: 1 running, 1020 sleeping

then once in 2-5 minutes, there for 2-3 seconds are:

1029 processes:67 running, 921 sleeping, 1 zombie, 40 lock

after this load average is 20-30 and dropping in 2-3min to 0.5

similar problem here: http://unix.derkeiler.com/Mailing-Li.../msg00551.html
and sadly, looks like there is no patch for FreeBSD 7

[skynet_tech]

and uname:

FreeBSD xxxxxx  7.0-RELEASE-p4 FreeBSD 7.0-RELEASE-p4 #4: Tue Sep 3 22:08:16 EEST 2008     xxxxxx:/usr/obj/usr/src/sys/SUN  amd64