linux-kernel - Re: [PATCH 3/3] perf/x86/rapl: Fix psys-energy event on Intel SPR platform

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Message-ID: <YBq3csfKeH7PaK39@hirez.programming.kicks-ass.net>
Date:   Wed, 3 Feb 2021 15:47:14 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     "Zhang, Rui" <rui.zhang@...el.com>
Cc:     "mingo@...hat.com" <mingo@...hat.com>,
        "acme@...nel.org" <acme@...nel.org>,
        "mark.rutland@....com" <mark.rutland@....com>,
        "alexander.shishkin@...ux.intel.com" 
        <alexander.shishkin@...ux.intel.com>,
        "jolsa@...hat.com" <jolsa@...hat.com>,
        "namhyung@...nel.org" <namhyung@...nel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "x86@...nel.org" <x86@...nel.org>,
        "kan.liang@...ux.intel.com" <kan.liang@...ux.intel.com>,
        "ak@...ux.intel.com" <ak@...ux.intel.com>
Subject: Re: [PATCH 3/3] perf/x86/rapl: Fix psys-energy event on Intel SPR
 platform


FWIW, your email is malformed, please wrap at 78 chars.

On Mon, Jan 25, 2021 at 06:11:14AM +0000, Zhang, Rui wrote:
> In short, the current code does not allow RAPL energy counter to
> return 0. And all the work I do is to allow Psys energy counter to
> return 0.

Ok.

> In this way, the Psys event is "valid" on all CPUs, so we don't need
> to handle the master thing.

So RAPL is mapped to DIEs, and IIRC we can have multiple DIEs per
Package. But the master thing is a Package.

Is this all moot because SPR has one DIE per Package? Because if it
would have more, there's be more interesting problems I suppose.