Re: [PATCH v2 2/2] powercap/rapl: reduce ipi calls

Jacob Pan
2016-01-13T16:22:28Z

On Wed, 13 Jan 2016 10:47:26 +0100 (CET)
Thomas Gleixner <tglx@linutronix.de> wrote:

> So here you actually use that new (misnomed) function, but for
>
> > +static void power_limit_irq_save_cpu(void *info)
>
> and
>
> > +static void power_limit_irq_restore_cpu(void *info)
>
> you use a bog standard smp function call. What's the benefit of
> adding that rmw function over a bog standard smp function call if you
> can only use it for one instance of the same pattern?
>
> Boris asked you the same question here
>
> https://lkml.kernel.org/r/20151220152749.GA29805@pd.tnic
>
> but you decided to ignore it.
+Borislav,

Thanks for bring this out. I didn't mean to ignore. I thought my point
was stated in the commit message there was no point of going back and
forth. Read-Modify-Write is quite common, not just for RAPL could be
used by future code. Sorry if I wasn't clear.

Jacob