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

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Message-ID: <20160113163610.GH12897@pd.tnic>
Date:	Wed, 13 Jan 2016 17:36:10 +0100
From:	Borislav Petkov <bp@...en8.de>
To:	Jacob Pan <jacob.jun.pan@...ux.intel.com>
Cc:	Thomas Gleixner <tglx@...utronix.de>,
	LKML <linux-kernel@...r.kernel.org>,
	Linux PM <linux-pm@...r.kernel.org>,
	Rafael Wysocki <rafael.j.wysocki@...el.com>,
	"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...hat.com>,
	X86 Kernel <x86@...nel.org>,
	Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
	Peter Zijlstra <peterz@...radead.org>
Subject: Re: [PATCH v2 2/2] powercap/rapl: reduce ipi calls

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_*.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.