Re: [PATCH] local_irq_disable removal

From: Daniel Walker
Date: Sun Jun 12 2005 - 10:48:20 EST




I was just trying to get an idea of the possible slow down if any, and for
x86 I'm convinced that it's not a slowdown..

Daniel

On Sun, 12 Jun 2005, Zwane Mwaikambo wrote:

> On Sat, 11 Jun 2005, Daniel Walker wrote:
>
> > Interesting .. So "cli" takes 7 cycles , "sti" takes 7 cycles. The current
> > method does "lea" which takes 1 cycle, and "or" which takes 1 cycle. I'm
> > not sure if there is any function call overhead .. So the soft replacment
> > of cli/sti is 70% faster on a per instruction level .. So it's at least
> > not any slower .. Does everyone agree on that?
>
> Well you also have to take into account the memory access, so it's not
> always that straightforward.
>
> Zwane
>
>

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