* [ppc] Disparity between sys_clock_getres and vdso implementation @ 2008-01-27 14:02 ` Sripathi Kodi 0 siblings, 0 replies; 8+ messages in thread From: Sripathi Kodi @ 2008-01-27 14:02 UTC (permalink / raw) To: paulus; +Cc: linuxppc-dev, linux-kernel, john stultz 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? Thanks, Sripathi. ^ permalink raw reply [flat|nested] 8+ messages in thread
* [ppc] Disparity between sys_clock_getres and vdso implementation @ 2008-01-27 14:02 ` Sripathi Kodi 0 siblings, 0 replies; 8+ messages in thread From: Sripathi Kodi @ 2008-01-27 14:02 UTC (permalink / raw) To: paulus; +Cc: linux-kernel, linuxppc-dev, john stultz 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? Thanks, Sripathi. ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [ppc] Disparity between sys_clock_getres and vdso implementation 2008-01-27 14:02 ` Sripathi Kodi @ 2008-02-04 6:08 ` Tony Breeds -1 siblings, 0 replies; 8+ messages in thread From: Tony Breeds @ 2008-02-04 6:08 UTC (permalink / raw) To: Sripathi Kodi; +Cc: linuxppc-dev, paulus, linux-kernel, john stultz 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 linux.conf.au http://linux.conf.au/ || http://lca2008.linux.org.au/ Jan 28 - Feb 02 2008 The Australian Linux Technical Conference! ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [ppc] Disparity between sys_clock_getres and vdso implementation @ 2008-02-04 6:08 ` Tony Breeds 0 siblings, 0 replies; 8+ messages in thread From: Tony Breeds @ 2008-02-04 6:08 UTC (permalink / raw) To: Sripathi Kodi; +Cc: paulus, linux-kernel, linuxppc-dev, john stultz 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 linux.conf.au http://linux.conf.au/ || http://lca2008.linux.org.au/ Jan 28 - Feb 02 2008 The Australian Linux Technical Conference! ^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH] [POWERPC] Use a sensible default for clock_getres() in the vdso. 2008-01-27 14:02 ` Sripathi Kodi @ 2008-02-05 5:16 ` Tony Breeds -1 siblings, 0 replies; 8+ messages in thread From: Tony Breeds @ 2008-02-05 5:16 UTC (permalink / raw) To: Sripathi Kodi; +Cc: linuxppc-dev, paulus, linux-kernel, john stultz 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! ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH] [POWERPC] Use a sensible default for clock_getres() in the vdso. @ 2008-02-05 5:16 ` Tony Breeds 0 siblings, 0 replies; 8+ messages in thread From: Tony Breeds @ 2008-02-05 5:16 UTC (permalink / raw) To: Sripathi Kodi; +Cc: paulus, linux-kernel, linuxppc-dev, john stultz 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! ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH] [POWERPC] Use a sensible default for clock_getres() in the vdso. 2008-02-05 5:16 ` Tony Breeds @ 2008-02-05 9:07 ` Chirag Jog -1 siblings, 0 replies; 8+ messages in thread From: Chirag Jog @ 2008-02-05 9:07 UTC (permalink / raw) To: Tony Breeds Cc: linuxppc-dev, Sripathi Kodi, paulus, linux-kernel, john stultz * 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 ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] [POWERPC] Use a sensible default for clock_getres() in the vdso. @ 2008-02-05 9:07 ` Chirag Jog 0 siblings, 0 replies; 8+ messages in thread From: Chirag Jog @ 2008-02-05 9:07 UTC (permalink / raw) To: Tony Breeds Cc: Sripathi Kodi, paulus, linux-kernel, linuxppc-dev, john stultz * 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 ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2008-02-05 9:08 UTC | newest] Thread overview: 8+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 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 2008-02-05 9:07 ` Chirag Jog
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