linux-kernel - Re: [RFC] perf/x86/intel/uncore: pmu->type->single

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Message-ID: <20161214113339.GA2960@krava>
Date:   Wed, 14 Dec 2016 12:33:39 +0100
From:   Jiri Olsa <jolsa@...hat.com>
To:     "Liang, Kan" <kan.liang@...el.com>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        "Jiri Olsa (jolsa@...nel.org)" <jolsa@...nel.org>,
        Andi Kleen <andi@...stfloor.org>,
        lkml <linux-kernel@...r.kernel.org>,
        Ingo Molnar <mingo@...nel.org>,
        Michael Petlan <mpetlan@...hat.com>
Subject: Re: [RFC] perf/x86/intel/uncore: pmu->type->single_fixed question

On Mon, Dec 12, 2016 at 02:49:03PM +0000, Liang, Kan wrote:
> 
> 
> > I really would prefer to move the thing to its own PMU.
> 
> The patch as below creates a new PMU to fix the issue.
> 
> Jirka, could you please try the patch on your machine?
> 
> 
> Thanks,
> Kan
> -------
> From 2de8b2eda6b54734e08a608b5fc8c367b94369d3 Mon Sep 17 00:00:00 2001
> From: Kan Liang <kan.liang@...el.com>
> Date: Mon, 12 Dec 2016 09:03:35 -0500
> Subject: [PATCH] perf/x86/intel/uncore: fix nonexistent clockticks event for
>  client uncore
> 
> The clockticks event can only be used by the first Cbox pmu. Other
> Cboxes don't allow to open clockticks event, eventhough it's announced
> via /sys/../events/..
> 
> For client uncore, there is only one clocktick fixed counter. Current
> kernel code forces that only the first box can access the fixed counter
> in uncore_pmu_event_init. But it doesn't take care of the the
> attr_groups. All the pmus of same type share the same attr_groups. If
> the clockticks event is set for the first box, user can also observe the
> event in other boxes.
> 
> The clocktick fixed counter is a standalone counter. It should be
> removed from the Cbox PMUs. A new type of PMU is added which only
> supports fixed counter events.
> 
> User observable changes with the patch.
> clockticks event is removed from Cbox. It will return unsupported, if
> uncore_cbox_0/clockticks/ is accessed. User may need to change their
> script to use uncore_clock/clockticks/ to instead.
> 
> Signed-off-by: Kan Liang <kan.liang@...el.com>

seems ok

Tested-by: Jiri Olsa <jolsa@...hat.com>

thanks,
jirka