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 <[EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]> --- 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! -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/