linux-kernel - Re: [RFC] change non-atomic bitops method

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Date:	Mon, 02 Feb 2015 10:53:16 -0800
From:	Laura Abbott <lauraa@...eaurora.org>
To:	"Wang, Yalin" <Yalin.Wang@...ymobile.com>,
	"'arnd@...db.de'" <arnd@...db.de>,
	"'linux-arch@...r.kernel.org'" <linux-arch@...r.kernel.org>,
	"'linux-kernel@...r.kernel.org'" <linux-kernel@...r.kernel.org>,
	"'linux@....linux.org.uk'" <linux@....linux.org.uk>,
	"'linux-arm-kernel@...ts.infradead.org'" 
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [RFC] change non-atomic bitops method

On 2/1/2015 7:55 PM, Wang, Yalin wrote:
> This patch change non-atomic bitops,
> add a if() condition to test it, before set/clear the bit.
> so that we don't need dirty the cache line, if this bit
> have been set or clear. On SMP system, dirty cache line will
> need invalidate other processors cache line, this will have
> some impact on SMP systems.
>

Any actual numbers to give an idea of the impact?

Thanks,
Laura


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