[patch 01/55] tile: Convert VDSO timekeeping to the precise mechanism

From: Thomas Gleixner
Date: Fri Jul 11 2014 - 09:44:08 EST


The code was only halfarsed converted to the new VSDO update mechanism
and still uses the inaccurate base value which lacks the fractional
part of xtime_nsec. Fix it up.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/tile/kernel/time.c | 9 ++++-----
arch/tile/kernel/vdso/vgettimeofday.c | 7 ++++---
2 files changed, 8 insertions(+), 8 deletions(-)

Index: tip/arch/tile/kernel/time.c
===================================================================
--- tip.orig/arch/tile/kernel/time.c
+++ tip/arch/tile/kernel/time.c
@@ -260,7 +260,6 @@ void update_vsyscall_tz(void)

void update_vsyscall(struct timekeeper *tk)
{
- struct timespec wall_time = tk_xtime(tk);
struct timespec *wtm = &tk->wall_to_monotonic;
struct clocksource *clock = tk->clock;

@@ -271,12 +270,12 @@ void update_vsyscall(struct timekeeper *
++vdso_data->tb_update_count;
smp_wmb();
vdso_data->xtime_tod_stamp = clock->cycle_last;
- vdso_data->xtime_clock_sec = wall_time.tv_sec;
- vdso_data->xtime_clock_nsec = wall_time.tv_nsec;
+ vdso_data->xtime_clock_sec = tk->xtime_sec;
+ vdso_data->xtime_clock_nsec = tk->xtime_nsec;
vdso_data->wtom_clock_sec = wtm->tv_sec;
vdso_data->wtom_clock_nsec = wtm->tv_nsec;
- vdso_data->mult = clock->mult;
- vdso_data->shift = clock->shift;
+ vdso_data->mult = tk->mult;
+ vdso_data->shift = tk->shift;
smp_wmb();
++vdso_data->tb_update_count;
}
Index: tip/arch/tile/kernel/vdso/vgettimeofday.c
===================================================================
--- tip.orig/arch/tile/kernel/vdso/vgettimeofday.c
+++ tip/arch/tile/kernel/vdso/vgettimeofday.c
@@ -83,10 +83,11 @@ int __vdso_gettimeofday(struct timeval *
if (count & 1)
continue;

- cycles = (get_cycles() - vdso_data->xtime_tod_stamp);
- ns = (cycles * vdso_data->mult) >> vdso_data->shift;
sec = vdso_data->xtime_clock_sec;
- ns += vdso_data->xtime_clock_nsec;
+ cycles = get_cycles() - vdso_data->xtime_tod_stamp;
+ ns = (cycles * vdso_data->mult) + vdso_data->xtime_clock_nsec;
+ ns >>= vdso_data->shift;
+
if (ns >= NSEC_PER_SEC) {
ns -= NSEC_PER_SEC;
sec += 1;


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