Regression in -current?

[Attilio Rao]

2010/1/24 Richard Todd <rmtodd at ichotolot.servalan.com>:
> Alexander Logvinov <avl at logvinov.com> writes:
>
>> Hello!
>>
>> On 24.01.2010 10:43 Dima Panov wrote:
>>> I see a strange regression since Friday's kernel, may be it's a kqueue-related.
>>> While building ports, now I never see 100% load of cpu, and portupgrade -fa
>>> takes ~7 hours for ~40 ports. Updating to current state (~3am VLAT) doesn't help.
>>>
>>> KDB and WITNESS/INVARIANTS disablen in kernel config
>
>>  I have a similar problem with r202904 amd64 kernel with interesting CPU
>> statistic:
>>
>> top output:
>>
>> last pid:  1885;  load averages:  2.89,  1.56,  0.66    up 0+00:02:47
>> 09:31:44
>> 72 processes:  3 running, 69 sleeping
>> _CPU:  0.0% user,  0.0% nice,  0.0% system,  0.0% interrupt,  0.0% idle_
>> Mem: 120M Active, 39M Inact, 153M Wired, 6968K Cache, 65M Buf, 3565M Free
>> Swap: 8192M Total, 8192M Free
>
> Yeah, I saw the same thing on my core2duo system (running in amd64 mode,
> dunno if that makes a difference.)  Caused the system to go *really* slow when
> powerd started and decided that since CPU usage was 0.00% it could safely
> throttle the CPU all the way down midway thru all the rc.d/* stuff
> executing. :-)
>
> As near as I can tell, the culprit is this rev (and the SVN #s you quote
> are consistent with this being the case):
>
>  SVN rev 202387 on 2010-01-15 16:04:30Z by attilio
>
>  Handling all the three clocks (hardclock, softclock, profclock) with the
>  LAPIC may lead to aliasing for softclock and profclock because frequencies
>  are sized in order to fit mainly hardclock.
>  atrtc used to take care of the softclock and profclock and it does still
>  do, if the LAPIC can't handle the clocks properly.
>
>  Revert the change when the LAPIC started taking charge of all three of
>  them and let atrtc handle softclock and profclock if not explicitly
>  requested. Such request can be made setting != 0 the new tunable
>  machdep.lapic_allclocks or if the new device ATPIC is not present
>  within the i386 kernel config (atrtc is linked to atpic presence).
>
> As a check, my current post-rev-202387 kernel has working clock if I boot with
>
>  machdep.lapic_allclocks=1

Can you all please do:

% sysctl kern.timecounter

Thanks,
Attilio



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