RELENG_7: interrupt eating whole cpu core
Dominic Fandrey
kamikaze at bsdforen.de
Wed Feb 6 19:45:05 UTC 2008
Chuck Swiger wrote:
> Hi, Dominic--
>
> On Feb 6, 2008, at 11:12 AM, Dominic Fandrey wrote:
>>> behaviour has changed. This is an HP 6510b GR695EA#ABD, if anyone
>>> thinks it might be helpful, I can supply you with a dmesg and the
>>> output of pciconf -lv.
>>
>> The problem remains with fresh sources:
>>
>> PID USERNAME THR PRI NICE SIZE RES STATE C TIME CPU COMMAND
>> 12 root 1 171 ki31 0K 16K RUN 0 22:04 97.85%
>> idle: cpu0
>> 37 root 1 -64 - 0K 16K CPU1 1 2:35 96.00%
>> irq14: ata0
>> 11 root 1 171 ki31 0K 16K RUN 1 19:32 6.40%
>> idle: cpu1
>>
>> The rip is done by k3b, so the drive is accessed through the cam
>> interface.
>
> What are the values being reported by "sysctl hw.ata"? If you're going
> to be burning CD/DVDs, you really want to make sure hw.ata.atapi_dma is on.
I cannot believe it was so trivial. The sysctl looks all right.
# sysctl hw.ata 0 /root
hw.ata.wc: 1
hw.ata.atapi_dma: 1
hw.ata.ata_dma: 1
But further research revealed:
# atacontrol mode acd0 0 /root
current mode = PIO4
# atacontrol mode acd0 udma33 0 /root
changed the load dramatically:
PID USERNAME THR PRI NICE SIZE RES STATE C TIME WCPU COMMAND
12 root 1 171 ki31 0K 16K RUN 0 52:54 100.00% idle: cpu0
11 root 1 171 ki31 0K 16K CPU1 1 23:36 94.29% idle: cpu1
1087 kamikaze 3 -8 0 133M 36168K physrd 1 1:09 3.17% k3b
37 root 1 -64 - 0K 16K WAIT 1 30:10 0.00% irq14: ata0
Thank you very much! I used to think that UDMA33 was the default for
CD-/DVD-Rom drives. I suppose I should review the BIOS settings or change
something in the hints file.
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