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Date: Wed, 27 Jan 2016 17:38:55 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Andi Kleen <andi@firstfloor.org>
Cc: Waiman Long <Waiman.Long@hpe.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
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	linux-kernel@vger.kernel.org, Scott J Norton <scott.norton@hp.com>,
	Douglas Hatch <doug.hatch@hp.com>
Subject: Re: [RFC PATCH 2/3] lib/list_batch, x86: Enable list
 insertion/deletion batching in x86-64
Message-ID: <20160127163855.GV6357@twins.programming.kicks-ass.net>
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On Tue, Jan 26, 2016 at 01:44:13PM -0800, Andi Kleen wrote:
> Waiman Long <Waiman.Long@hpe.com> writes:
> >
> > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> > index 330e738..443e41d 100644
> > --- a/arch/x86/Kconfig
> > +++ b/arch/x86/Kconfig
> > @@ -42,6 +42,7 @@ config X86
> >  	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
> >  	select ARCH_USE_BUILTIN_BSWAP
> >  	select ARCH_USE_CMPXCHG_LOCKREF		if X86_64
> > +	select ARCH_USE_LIST_BATCHING		if X86_64
> 
> I would make it unconditional. The code is simple enough
> and shouldn't have drawbacks on smaller systems.

I agree with the sentiment but would like to see a benchmark done on a
small system to verify all the same.