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Date: Mon, 25 Jan 2016 12:13:05 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Huang Rui <ray.huang@amd.com>
Cc: Borislav Petkov <bp@suse.de>, Ingo Molnar <mingo@kernel.org>,
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        Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>,
        Borislav Petkov <bp@alien8.de>, Fengguang Wu <fengguang.wu@intel.com>,
        Aaron Lu <aaron.lu@intel.com>
Subject: Re: [PATCH v3] perf/x86/amd/power: Add AMD accumulated power
 reporting mechanism
Message-ID: <20160125111305.GU6357@twins.programming.kicks-ass.net>
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On Mon, Jan 25, 2016 at 04:32:03PM +0800, Huang Rui wrote:
> +struct power_pmu {
> +	raw_spinlock_t		lock;
> +	struct list_head	active_list;

Maybe a dumb question, but what is that list for?

You only ever add/del events to/from it, you never iterate it. So why
keep it?

If you drop the list, the lock can go too I think, making all this stuff
simpler.