From: Chirag Jog <chirag@linux.vnet.ibm.com>
To: Tony Breeds <tony@bakeyournoodle.com>
Cc: linuxppc-dev@ozlabs.org, Sripathi Kodi <sripathik@in.ibm.com>,
paulus@samba.org, linux-kernel@vger.kernel.org,
john stultz <johnstul@us.ibm.com>
Subject: Re: [PATCH] [POWERPC] Use a sensible default for clock_getres() in the vdso.
Date: Tue, 5 Feb 2008 14:37:42 +0530 [thread overview]
Message-ID: <20080205090742.GA11087@linux.vnet.ibm.com> (raw)
In-Reply-To: <20080205051648.GX6887@bakeyournoodle.com>
* Tony Breeds <tony@bakeyournoodle.com> [2008-02-05 16:16:48]:
> 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?
>
> Can you try the attached patch and see it if works for you?
I tried this patch.
It seems to solve the reported problem and give a 1ns resolution.
Thanks.
--
Cheers,
Chirag Jog
WARNING: multiple messages have this Message-ID (diff)
From: Chirag Jog <chirag@linux.vnet.ibm.com>
To: Tony Breeds <tony@bakeyournoodle.com>
Cc: Sripathi Kodi <sripathik@in.ibm.com>,
paulus@samba.org, linux-kernel@vger.kernel.org,
linuxppc-dev@ozlabs.org, john stultz <johnstul@us.ibm.com>
Subject: Re: [PATCH] [POWERPC] Use a sensible default for clock_getres() in the vdso.
Date: Tue, 5 Feb 2008 14:37:42 +0530 [thread overview]
Message-ID: <20080205090742.GA11087@linux.vnet.ibm.com> (raw)
In-Reply-To: <20080205051648.GX6887@bakeyournoodle.com>
* Tony Breeds <tony@bakeyournoodle.com> [2008-02-05 16:16:48]:
> 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?
>
> Can you try the attached patch and see it if works for you?
I tried this patch.
It seems to solve the reported problem and give a 1ns resolution.
Thanks.
--
Cheers,
Chirag Jog
next prev parent reply other threads:[~2008-02-05 9:08 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-27 14:02 [ppc] Disparity between sys_clock_getres and vdso implementation Sripathi Kodi
2008-01-27 14:02 ` Sripathi Kodi
2008-02-04 6:08 ` Tony Breeds
2008-02-04 6:08 ` Tony Breeds
2008-02-05 5:16 ` [PATCH] [POWERPC] Use a sensible default for clock_getres() in the vdso Tony Breeds
2008-02-05 5:16 ` Tony Breeds
2008-02-05 9:07 ` Chirag Jog [this message]
2008-02-05 9:07 ` Chirag Jog
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