Re: [PATCH 14/23] clocksource: increase initcall priority

From: Daniel Walker
Date: Wed Jan 31 2007 - 11:44:43 EST


On Wed, 2007-01-31 at 12:50 +0100, Ingo Molnar wrote:
> * Daniel Walker <dwalker@xxxxxxxxxx> wrote:
>
> > -module_init(init_acpi_pm_clocksource);
> > +/*
> > + * This clocksource is removed from the clocksource_initcall
> > + * macro since it's mandatory for it to be in fs_initcall as the
> > + * highest initcall level, or else it doesn't work properly with
> > + * it's PCI fix ups.
> > + */
> > +fs_initcall(init_acpi_pm_clocksource);
>
> ugh - this bit looks quite interesting.
>
> what's the purpose of this patch? Switching to high-res timers should be
> done late in the bootup - in case there's a problem it's more
> debuggable, etc.

The timekeeping code, and hrt/dynamic tick both wait till after boot up
to switch to high res mode ..

The specific code block you commented on above was added cause acpi_pm
has special pci fixups that don't function properly earlier in boot up.
So it can't be arbitrarily raised to order in the initcall sequence ..

Daniel


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