Re: [PATCH] local_irq_disable removal

From: Ingo Molnar
Date: Mon Jun 13 2005 - 02:56:03 EST



* Sven-Thorsten Dietrich <sdietrich@xxxxxxxxxx> wrote:

> On Sat, 2005-06-11 at 22:03 +0200, Ingo Molnar wrote:
> > * Esben Nielsen <simlo@xxxxxxxxxx> wrote:
> >
> > > > the jury is still out on the accuracy of those numbers. The test had
> > > > RT_DEADLOCK_DETECT (and other -RT debugging features) turned on, which
> > > > mostly work with interrupts disabled. The other question is how were
> > > > interrupt response times measured.
> > > >
> > > You would accept a patch where I made this stuff optional?
> >
> > I'm not sure why. The soft-flag based local_irq_disable() should in fact
> > be a tiny bit faster than the cli based approach, on a fair number of
> > CPUs. But it should definitely not be slower in any measurable way.
> >
>
> Is there any such SMP concept as a local_preempt_disable() ?

preempt_disable() is always 'local'. (has effect only on the current
CPU)

Ingo
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