One-shot-oriented event timers management
mav at FreeBSD.org
Thu Sep 2 10:20:48 UTC 2010
Ian FREISLICH wrote:
> On Wed, Sep 1, 2010 at 2:16 PM, Alexander Motin <mav at freebsd.org> wrote:
>> Brandon Gooch wrote:
>>> This latest patch causes an interrupt storm with the HPET timer on my
>>> system. The machine took about 8 minutes to boot and bring me to a
>>> login prompt. System interactivity (i.e. input from keyboard, output
>>> on console) was fine, but after checking the output of `systat vmstat
>>> -1`, I saw the interrupt rate on each HPET entry was over 120k!
>>> Can I provide any useful detail? Of course, test patches are always welcom
> e :)
>> I was able to reproduce alike storm in some situations.
>> Try new version: http://people.freebsd.org/~mav/timers_oneshot7.patch
> Interrupt rates are definitely reduced.
> [mini] /usr/home/ianf $ vmstat -i
> interrupt total rate
> irq1: atkbd0 1154 1
> irq9: acpi0 10829 15
> irq16: ath0 uhci3+ 16226 23
> irq18: uhci2 16 0
> irq19: uhci1+ 7090 10
> irq20: hpet0 169288 240
> irq23: uhci0 ehci0 64 0
> irq256: hdac0 187 0
> Total 204854 291
Nice. But 240 still quite a lot. Have you applied tm6292_idle.patch and
was this system idle at the moment?
> [mini] /usr/home/ianf $ sysctl dev.cpu |grep usage
> dev.cpu.0.cx_usage: 0.00% 0.04% 0.80% 99.15% last 1601us
> dev.cpu.1.cx_usage: 0.00% 0.00% 0.65% 99.34% last 2078us
It is the first time I see in practice system reporting 4 different ACPI
C-states. What is this system? What CPU is there? Could you show me full
`sysctl dev.cpu` output?
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