r266165: powerd hang sytem on MacbookPro 2013

[Colin Percival]

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?

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