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Date: Mon, 4 Feb 2008 17:08:30 +1100
To: Sripathi Kodi <sripathik@in.ibm.com>
Subject: Re: [ppc] Disparity between sys_clock_getres and vdso implementation
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From: tony@bakeyournoodle.com (Tony Breeds)
Cc: linuxppc-dev@ozlabs.org, paulus@samba.org, linux-kernel@vger.kernel.org,
	john stultz <johnstul@us.ibm.com>
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On Sun, Jan 27, 2008 at 07:32:59PM +0530, Sripathi Kodi wrote:
> Hi Paul,
> 
> On PPC, I see a disparity between clock_getres implementations in the
> vdso and syscall. I am using a IBM Openpower hardware and 2.6.24 kernel
> with CONFIG_HIGH_RES_TIMERS=y. 
> 
> clock_getres call for CLOCK_REALTIME returns 1 millisecond. However,
> when I edit arch/powerpc/kernel/vdso*/gettimeofday.S to force it to use 
> sys_clock_getres, I get 1 nanosecond resolution. The code in vdso seems
> to be returning some pre-defined (incorrect) variables.
> 
> Could you please let me know the reason for this? Is it something that
> should be fixed in vdso?

Almost certainly It's something I missed when I enabled highres timers
on powerpc.

I'll fix this tomorrow.

Yours Tony

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