Re: remove cpu hotplug bustification in cpufreq.

From: Dave Jones
Date: Tue Jul 25 2006 - 16:45:35 EST


On Tue, Jul 25, 2006 at 08:54:49PM +0200, Ingo Molnar wrote:
>
> * Linus Torvalds <torvalds@xxxxxxxx> wrote:
>
> > The current -git tree will complain about some of the more obvious
> > problems. If you see a "Lukewarm IQ" message, it's a sign of somebody
> > re-taking a cpu lock that is already held.
> testing on my latest-rawhide laptop (kernel-2.6.17-1.2445.fc6 and later
> rpms have this change) seems to have pushed the problem over to another
> lock:
>
> S06cpuspeed/1580 is trying to acquire lock:
> (&policy->lock){--..}, at: [<c06075f9>] mutex_lock+0x21/0x24
>
> but task is already holding lock:
> (cpu_bitmask_lock){--..}, at: [<c06075f9>] mutex_lock+0x21/0x24
>
> which lock already depends on the new lock.
>
> and we also get the:
>
> Lukewarm IQ detected in hotplug locking
>
> message :-| Find the full bootlog below. And i dont understand the
> cpufreq code well enough to fix this. In fact, does anyone understand
> it? :-/

Things used to be fairly simple until hotplug cpu came along :-/
Each day, I'm getting more of the opinion that my patch just ripping
out this garbage is the right solution.

Dave

--
http://www.codemonkey.org.uk
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