Re: Make sure we populate the initroot filesystem late enough

From: Segher Boessenkool <segher@kernel.crashing.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Woodhouse <dwmw2@infradead.org>,
	torvalds@linux-foundation.org, john stultz <johnstul@us.ibm.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linuxppc-dev@ozlabs.org,
	Paul TBBle Hampson <Paul.Hampson@Pobox.com>
Subject: Re: Make sure we populate the initroot filesystem late enough
Date: Tue, 27 Feb 2007 12:58:28 +0100	[thread overview]
Message-ID: <3ac1a55a11baddefb903f24b988566fe@kernel.crashing.org> (raw)
In-Reply-To: <1172558897.11949.43.camel@localhost.localdomain>

>>> I've not been able to reproduce it since, but I know others (BCC'ed 
>>> on
>>> this note) have seen it and might prod them to come forth with 
>>> details
>>> (and broken .config files)
>>
>> In my case, disabling CPU_FREQ_PMAC made the failure go away.
>> After reverting this patch, CPU_FREQ_PMAC is once again operating
>> successfully, so far.
>
> Hrm.. which cpufreq method is used on both your machines ? If it's the
> one involving the PMU, it does involve a full hard reset of the
> processor (with appropriate cache flushes etc...), maybe something's
> going wrong in that area....

It's most likely a red herring, lots of config changes
make the bug go away on some kernel versions (but not
on others); the problem is very sensitive to changes in
memory layout.

Segher