Date: Tue, 20 Mar 2012 09:33:06 -0400 From: Gary Palmer <gpalmer@freebsd.org> To: Matt Thyer <matt.thyer@gmail.com> Cc: freebsd-stable@freebsd.org, Ivan Voras <ivoras@freebsd.org> Subject: Re: 157k interrupts per second causing 60% CPU load on idle system Message-ID: <20120320133306.GA5044@in-addr.com> In-Reply-To: <CACM2%2B-79tricaEJfpvsi-vETR1UGWYjKQU__DYYZvW=eGgmKOw@mail.gmail.com> References: <CACM2%2B-46zHafjZo0O1dNNvEJm%2B2sUcYboBWwhJ8NxVhXyvpBZQ@mail.gmail.com> <jk9mv3$n6k$2@dough.gmane.org> <CACM2%2B-6-_ocDL=4-kz31ejOB2jDb9_hjXUYKJ0-xqNfK2esorg@mail.gmail.com> <CAF-QHFWT4urs_JsXExEph94OyXU2ZHhDtitgwzUjvKciBLPgwQ@mail.gmail.com> <CACM2%2B-79tricaEJfpvsi-vETR1UGWYjKQU__DYYZvW=eGgmKOw@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, Mar 20, 2012 at 11:10:10PM +1030, Matt Thyer wrote: > On 20 March 2012 22:24, Ivan Voras <ivoras@freebsd.org> wrote: > > > On 20 March 2012 12:52, Matt Thyer <matt.thyer@gmail.com> wrote: > > > On 20 March 2012 21:12, Ivan Voras <ivoras@freebsd.org> wrote: > > >> > > >> 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". > > >> > > >> > > > interrupt total rate > > > irq16: uhci0+ 3392184862 126692 > > > > Ok, something's probably wrong with USB. Can you disable it in BIOS? > > > > > > > cpu0: timer 53549677 1999 > > > irq256: mps0 2643187 98 > > > irq257: re0 5508108 205 > > > irq258: ahci0 160717 6 > > > cpu1: timer 53525300 1999 > > > cpu2: timer 53525300 1999 > > > cpu3: timer 53525296 1999 > > > Total 3614622447 134999 > > > > > > > I did just update the BIOS at about the same time so the difference may be > due to that change. > > I'll try a few things such as: > > - Unplugging any USB things (I've only got a keyboard plugged in). > - Downgrade BIOS. > > I'll get back to you all soon. It would be interesting to know if there are other devices on irq16 also. grep 'irq 16' /var/run/dmesg.boot I think the '+' on the irq16 line from vmstat means the interrupt is shared, but the man page doesn't mention it so I'm not 100% sure Thanks, Gary
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20120320133306.GA5044>