Re: [PATCH] x86: fix idle notifier not being called in CONFIG_X86_32

From: Ingo Molnar
Date: Wed Mar 06 2013 - 05:36:37 EST



* Mansoor, Illyas <illyas.mansoor@xxxxxxxxx> wrote:

> > * Illyas Mansoor <illyas.mansoor@xxxxxxxxx> wrote:
> >
> > > Idle notifier not registered if CONFIG_X86_32 is defined, those
> > > callbacks are empty for X86_32 platform.
> > >
> > > ifdef CONFIG_X86_64
> > > void enter_idle(void);
> > > void exit_idle(void);
> > > else
> > > static inline void enter_idle(void) { } static inline void
> > > exit_idle(void) { } static inline void __exit_idle(void) { } endif
> > >
> > > Make this work on X86_32 platforms by
> > > removing the restriction for X86_64
> >
> > What will they be used for?
>
> It's being used by interactive governor, and since the idle notifications are not
> received It breaks the governor functionality on X86_32

But we never allowed idle notifiers on 32-bit and wanted to phase them out even on
x86-64 as well.

There's ongoing work to improve power saving in the scheduler - see Alex Shi's
patchset on lkml: I think the two pieces of code should cooperate within the
scheduler instead of going in two directions, duplicating effort and getting in each
other's way ...

Thanks,

Ingo
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