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Re: [PATCH] x86: set_cyc2ns_scale() remove tsc_now and ns_now

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To: Andi Kleen <andi@...>
Cc: Karsten Wiese <fzu@...>, <linux-kernel@...>
Date: Friday, April 11, 2008 - 3:55 am

* Andi Kleen <andi@firstfloor.org> wrote:


recent CPUs have constant-freq TSCs so it's mostly a legacy issue, but 
the affected installed base is still significant to warrant a fix.

we dont really have to worry about complications like grace periods - 
higher layers in the scheduler protect against temporary sched_clock() 
outliers. So i think this can all be done much simpler. Just get rid of 
the global cpu_khz notion, sched_clock() should simply follow the ->freq 
value - and that's it.

	Ingo
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Messages in current thread:
[PATCH] x86: set_cyc2ns_scale() remove tsc_now and ns_now, Karsten Wiese, (Thu Apr 10, 5:31 pm)
Re: [PATCH] x86: set_cyc2ns_scale() remove tsc_now and ns_now, Ingo Molnar, (Fri Apr 11, 3:55 am)
Re: [PATCH] x86: set_cyc2ns_scale() remove tsc_now and ns_now, Guillaume Chazarain, (Fri Apr 11, 4:25 am)
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