r266165: powerd hang sytem on MacbookPro 2013

[Huang Wen Hui]

2014-05-19 21:03 GMT+08:00, Colin Percival <cperciva at freebsd.org>:
> On 05/18/14 15:43, Adrian Chadd wrote:
>> On 18 May 2014 08:32, Huang Wen Hui <huanghwh at gmail.com> wrote:
>>> Hi,
>>> Before r266165, There is no "dev.cpu.0.freq"  on my  MacbookPro 2013, now
>>> I
>>> got:
>>>
>>> #sysctl dev.cpu.0.freq
>>> dev.cpu.0.freq: 2601
>>>
>>> but If start powerd, system will quickly hang, both keyboard and
>>> ethernet
>>> are not respond.
>
> Well, the good news is that r266165 is working: It makes that sysctl
> visible
> in situations where it used to be (accidentally) inoperative.  The bad news
> is that you seem to be running into a problem with the now-functional power
> management code.
>
> I suggest disabling powerd in /etc/rc.conf, and manually adjusting the
> clock
> frequency using dev.cpu.0.freq.  Does it repeatably die at a certain point?
> Does it die immediately at that point, or after some time?  Do you always
> get the same hang?
OK, I use sysctl dev.cpu.0.freq=xxxx many times, all freq change cause
100% hang, detail:
freq 1000, 1200, 1500, 1700, 1900, it hangs after some time.
freq 800, 2100, 2600, it hangs immediately, but not 100%.
freq 2400, it always hangs immediately, I could not see command sysctl
return message.

I think I got the same hang, keyboard and ethernet no respond, but no
panic message.


>
> The most likely problem IMHO is that your CPU isn't actually able to run
> with
> the frequency/voltage pairs that it thinks it can run with, and so reducing
> the clock speed is causing bitflip errors.  But if that's the case you will
> probably see a variety of hangs/panics and they won't always occur
> immediately.
>
> --
> Colin Percival
> Security Officer Emeritus, FreeBSD | The power to serve
> Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid
>
>