Re: [PATCH] local_irq_disable removal

Daniel Walker
2005-06-12T04:32:32Z

On Sun, 12 Jun 2005, Karim Yaghmour wrote:

>
> 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?
>
> The proof is in the pudding: it's not for nothing that the results
> we published earlier show that the mere enabling of Adeos actually
> increases Linux's performance under heavy load.

Why do you think that is? Is ADEOS optimized for specific machine
configurations?

> That being said, I'm not sure exactly why you guys are reinventing the
> wheel. Adeos already does this soft-cli/sti stuff for you, it's been
> available for a few years already, tested, and ported to a number of
> architectures, and is generalized, why not just adopt it? After all,
> like I've been saying for some time, it isn't mutually exclusive with
> PREEMPT_RT.

It doesn't seem like one could really merge the two. From what I've read
, it seem like ADEOS is something completly indepedent . It would be linux
and ADEOS , but never just linux .

Daniel