Matt Thyer
2012-Mar-20 05:27 UTC
157k interrupts per second causing 60% CPU load on idle system
I've upgraded my FreeBSD-STABLE NAS from r225723 (22nd Sept 2011) to r232477 (4th Mar 2012) and am finding that a system process called "intr" is now constantly using about 60% of 1 CPU starting a short time after reboot (possibly triggered by use of the samba server). When this starts, systat -vm 1 says that the system is 85% idle and 14% interrupt handling. It says that there's around 157k interrupts per second. After a reboot the system is back to it's normal state doing between 3 and 250 or so interrupts per second. The hardware is an Intel Core i3-530 (dual core @ 2.93 GHz with Hyperthreading) with 8 GB RAM (2x4GB) on a Gigabyte H55M-D2H rev 1.3 motherboard running the latest BIOS (F4). The system runs a GENERIC kernel with the following significant items in /boot/loader.conf: zfs_load="YES" aio_load="YES" ahci_load="YES" geom_mirror_load="YES" vfs.root.mountfrom="zfs:zroot" vboxdrv_load="YES" It has 2 x 300 GB disks for the system with GPT partitioning and zmirror for the OS ala http://wiki.freebsd.org/RootOnZFS/GPTZFSBoot/Mirror I have swap on a gmirror as I want swap to survive the loss of one system disk. The NAS data is on a raidz2 pool of 8 disks connected to a SuperMicro AOC-USAS2-L8i (flashed to behave as an AOC-USAS2-L8e). The system is basically a CIFS NAS with ports/net/samba36 built with AIO_SUPPORT and configured like: socket options = SO_RCVBUF=131072 SO_SNDBUF=131072 TCP_NODELAY min receivefile size=16384 use sendfile=true aio read size = 16384 aio write size = 16384 aio write behind = true The only other interesting workload on the box is a java Minecraft server using ports/java/jdk16. I'm going to try to reproduce the problem in a VM and binary search down to the revision where it started as soon as I can work out a reliable way to trigger the behaviour (as it doesn't start at boot time). Any idea what could be the cause ?
Ivan Voras
2012-Mar-20 10:43 UTC
157k interrupts per second causing 60% CPU load on idle system
On 20/03/2012 06:26, Matt Thyer wrote:> I've upgraded my FreeBSD-STABLE NAS from r225723 (22nd Sept 2011) to > r232477 (4th Mar 2012) and am finding that a system process called "intr" > is now constantly using about 60% of 1 CPU starting a short time after > reboot (possibly triggered by use of the samba server). > > When this starts, systat -vm 1 says that the system is 85% idle and 14% > interrupt handling. > It says that there's around 157k interrupts per second. >Ok, but *which* interrupt is getting triggered? Please send the output of "vmstat -i". -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 260 bytes Desc: OpenPGP digital signature Url : http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20120320/5016e47b/signature.pgp
Mike Tancsa
2012-Mar-21 23:44 UTC
157k interrupts per second causing 60% CPU load on idle system
On 3/20/2012 1:26 AM, Matt Thyer wrote:> I've upgraded my FreeBSD-STABLE NAS from r225723 (22nd Sept 2011) to > r232477 (4th Mar 2012) and am finding that a system process called "intr" > is now constantly using about 60% of 1 CPU starting a short time after > reboot (possibly triggered by use of the samba server). > > When this starts, systat -vm 1 says that the system is 85% idle and 14% > interrupt handling. > It says that there's around 157k interrupts per second. > > Any idea what could be the cause ?This sounds like the problem I had with my intel board. BIOS update fixed it. What chipset and MB vendor do you have ? /usr/ports/sysutils/dmidecode is handy for digging up BIOS and chipset info http://lists.freebsd.org/pipermail/freebsd-questions/2012-March/239394.html ---Mike -- ------------------- Mike Tancsa, tel +1 519 651 3400 Sentex Communications, mike@sentex.net Providing Internet services since 1994 www.sentex.net Cambridge, Ontario Canada http://www.tancsa.com/