timekeeping: Increase granularity of read_persistent_clock()
The persistent clock of some architectures (e.g. s390) have a
better granularity than seconds. To reduce the delta between the
host clock and the guest clock in a virtualized system change the
read_persistent_clock function to return a struct timespec.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Daniel Walker <dwalker@fifo99.com>
LKML-Reference: <20090814134811.013873340@de.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/mips/lasat/sysctl.c b/arch/mips/lasat/sysctl.c
index 8f88886..3f04d4c 100644
--- a/arch/mips/lasat/sysctl.c
+++ b/arch/mips/lasat/sysctl.c
@@ -92,10 +92,12 @@
int proc_dolasatrtc(ctl_table *table, int write, struct file *filp,
void *buffer, size_t *lenp, loff_t *ppos)
{
+ struct timespec ts;
int r;
if (!write) {
- rtctmp = read_persistent_clock();
+ read_persistent_clock(&ts);
+ rtctmp = ts.tv_sec;
/* check for time < 0 and set to 0 */
if (rtctmp < 0)
rtctmp = 0;
@@ -134,9 +136,11 @@
void *oldval, size_t *oldlenp,
void *newval, size_t newlen)
{
+ struct timespec ts;
int r;
- rtctmp = read_persistent_clock();
+ read_persistent_clock(&ts);
+ rtctmp = ts.tv_sec;
if (rtctmp < 0)
rtctmp = 0;
r = sysctl_intvec(table, oldval, oldlenp, newval, newlen);