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

Jacob Pan
2016-01-13T17:51:25Z

On Wed, 13 Jan 2016 17:36:10 +0100
Borislav Petkov <bp@alien8.de> wrote:

> On Wed, Jan 13, 2016 at 08:21:13AM -0800, Jacob Pan wrote:
> > 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.
>
> But it also shows that it doesn't suffice for all your needs. So why
> add it?
>
> You can much better define your own functions which do all the MSR
> handling you require and call them with smp_call_function_*.
>
yeah, that is what I did in the original patch.
https://lkml.org/lkml/2015/12/7/1090

Then i was suggested to add a rmw msr api for the common good :), I
think it is a good idea since such operation is not limited to RAPL
driver. Other register access APIs such as regmap have more complete
selections.

Jacob