Date: Wed, 6 Mar 2013 22:15:52 +0100 (CET)
From: Thomas Gleixner <tglx@linutronix.de>
To: "H. Peter Anvin" <hpa@linux.intel.com>
cc: Feng Tang <feng.tang@intel.com>, John Stultz <john.stultz@linaro.org>,
        Ingo Molnar <mingo@elte.hu>,
        Jason Gunthorpe <jgunthorpe@obsidianresearch.com>, x86@kernel.org,
        Len Brown <lenb@kernel.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        linux-kernel@vger.kernel.org, gong.chen@linux.intel.com
Subject: Re: [PATCH v3 4/5] clocksource: Enable clocksource_cyc2ns() to cover
 big cycles
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On Wed, 6 Mar 2013, H. Peter Anvin wrote:

> On 03/06/2013 06:09 AM, Thomas Gleixner wrote:
> > 
> > This breaks everything which does not have a 64/32bit divide
> > instruction. And you can't replace it with do_div() as that would
> > impose massive overhead on those architectures in the fast path.
> > 
> 
> Could we do the same kind of scaling-by-multiplication that we do in
> kernel/time.c for this?

Not sure what you are referring to. kernel/time.c contains a lot of stuff :)

Thanks,

	tglx
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