Date: Thu, 19 Nov 2015 10:40:00 +0000
From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        LKML <linux-kernel@vger.kernel.org>, Mans Rullgard <mans@mansr.com>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Nicolas Pitre <nico@linaro.org>, Tony Lindgren <tony@atomide.com>,
        Sebastian Frias <sebastian_frias@sigmadesigns.com>
Subject: Re: [PATCH] clocksource: Store reg field within struct clocksource
Message-ID: <20151119104000.GW8644@n2100.arm.linux.org.uk>
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On Thu, Nov 19, 2015 at 11:36:53AM +0100, Thomas Gleixner wrote:
> On Thu, 19 Nov 2015, Russell King - ARM Linux wrote:
> > Maybe the ____cacheline_aligned is inappropriate then, because it means
> > any wrapping of struct clocksource has exactly the same problem.
> 
> We could do that, but that does not necessarily solve the cache
> footprint issue. Aside of that we'd need to add ____cacheline_aligned
> to quite some of the statically allocated clocksource declarations.

Sorry, but it does solve the cache footprint issue, because it would
have the effect of moving 'reg' right into the same cache line as
the 'read' pointer.

Yes, we'd need ____cacheline_aligned at the static declarations, but
surely that's better than constantly having to stuff implementation
specific data into struct clocksource.

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