Messages in this thread |  | | Subject | Re: [PATCH 2/4]: CPUIDLE: Introduce architecture independent cpuidle_pm_idle in drivers/cpuidle/cpuidle.c | | From | Peter Zijlstra <> | | Date | Fri, 28 Aug 2009 09:01:12 +0200 |
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On Fri, 2009-08-28 at 08:48 +0200, Peter Zijlstra wrote: > > > void cpuidle_install_idle_handler(void) > > { > > ......... > > ......... > > cpuidle_pm_idle = cpuidle_idle_call; > > } > > All I'm seeing here is a frigging mess. > > How on earths can something called: cpuidle_install_idle_handler() have > a void argument, _WHAT_ handler is it going to install?
Argh, now I see, it installs itself as the platform idle handler.
so cpuidle_install_idle_handler() pokes at the unmanaged pm_idle pointer to make cpuidle take control.
On module load it does:
pm_idle_old = pm_idle;
then in the actual idle loop it does:
if (!dev || !dev->enabled) { if (pm_idle_old) pm_idle_old();
who is to say that the pointer stored at module init time is still around at that time?
So cpuidle recognised the pm_idle stuff was a flaky, but instead of fixing it, they build a whole new layer on top of it. Brilliant.
/me goes mark this whole thread read, I've got enough things to do.
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