From: tony@bakeyournoodle•com (Tony Breeds)
To: Sripathi Kodi <sripathik@in•ibm.com>
Cc: linuxppc-dev@ozlabs•org, paulus@samba•org,
linux-kernel@vger•kernel.org, john stultz <johnstul@us•ibm.com>
Subject: [PATCH] [POWERPC] Use a sensible default for clock_getres() in the vdso.
Date: Tue, 5 Feb 2008 16:16:48 +1100 [thread overview]
Message-ID: <20080205051648.GX6887@bakeyournoodle.com> (raw)
In-Reply-To: <200801271932.59823.sripathik@in.ibm.com>
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?
From: Tony Breeds <tony@bakeyournoodle•com>
Subject: [PATCH] [POWERPC] Use a sensible default for clock_getres() in the vdso.
This ensures that the syscall and the (fast) vdso versions of clock_getres()
will return the same resolution.
Signed-off-by: Tony Breeds <tony@bakeyournoodle•com>
---
arch/powerpc/kernel/asm-offsets.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index ed083fe..e6e4928 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -22,6 +22,7 @@
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/suspend.h>
+#include <linux/hrtimer.h>
#ifdef CONFIG_PPC64
#include <linux/time.h>
#include <linux/hardirq.h>
@@ -312,7 +313,7 @@ int main(void)
DEFINE(CLOCK_REALTIME, CLOCK_REALTIME);
DEFINE(CLOCK_MONOTONIC, CLOCK_MONOTONIC);
DEFINE(NSEC_PER_SEC, NSEC_PER_SEC);
- DEFINE(CLOCK_REALTIME_RES, TICK_NSEC);
+ DEFINE(CLOCK_REALTIME_RES, (KTIME_MONOTONIC_RES).tv64);
#ifdef CONFIG_BUG
DEFINE(BUG_ENTRY_SIZE, sizeof(struct bug_entry));
--
1.5.4
Yours Tony
linux.conf.au http://linux.conf.au/ || http://lca2008.linux.org.au/
Jan 28 - Feb 02 2008 The Australian Linux Technical Conference!
next prev parent reply other threads:[~2008-02-05 5:18 UTC|newest]
Thread overview: 4+ 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
2008-02-04 6:08 ` Tony Breeds
2008-02-05 5:16 ` Tony Breeds [this message]
2008-02-05 9:07 ` [PATCH] [POWERPC] Use a sensible default for clock_getres() in the vdso Chirag Jog
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20080205051648.GX6887@bakeyournoodle.com \
--to=tony@bakeyournoodle$(echo .)com \
--cc=johnstul@us$(echo .)ibm.com \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=linuxppc-dev@ozlabs$(echo .)org \
--cc=paulus@samba$(echo .)org \
--cc=sripathik@in$(echo .)ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox