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Date: Thu, 22 Sep 2016 15:23:47 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Waiman Long <Waiman.Long@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@kernel.org>,
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        Jason Low <jason.low2@hpe.com>, Scott J Norton <scott.norton@hpe.com>,
        Douglas Hatch <doug.hatch@hpe.com>
Subject: Re: [RFC PATCH v2 3/5] futex: Throughput-optimized (TO) futexes
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On Tue, Sep 20, 2016 at 09:42:41AM -0400, Waiman Long wrote:
> +/*
> + * Spinning threshold before enabling lock handoff.
> + * Each sleep will decrement the threshold by 1/32 of the start value.
> + */
> +#define TO_SPIN_THRESHOLD	(1 << 13)
> +#define TO_SLEEP_DECREMENT	(TO_SPIN_THRESHOLD/32)

Argh, we should really get rid of those stupid numbers. Wasn't there a
patch set working on implementing paravirt functions that would make all
this fixable in a sane way?