uml: virtualized time fix
With the current timekeeping, !CONFIG_UML_REAL_TIME_CLOCK has
inconsistent behavior. Previously, gettimeofday could be (and was)
isolated from the clock ticking. Now, it's not, so when
CONFIG_UML_REAL_TIME_CLOCK is disabled, gettimeofday must progress in
lockstep with the clock, making it fully virtual.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
index 9fd80ee..cd7349d 100644
--- a/arch/um/kernel/time.c
+++ b/arch/um/kernel/time.c
@@ -34,8 +34,8 @@
return (unsigned long long)jiffies_64 * (1000000000 / HZ);
}
-static unsigned long long prev_nsecs[NR_CPUS];
#ifdef CONFIG_UML_REAL_TIME_CLOCK
+static unsigned long long prev_nsecs[NR_CPUS];
static long long delta[NR_CPUS]; /* Deviation per interval */
#endif
@@ -94,7 +94,12 @@
do_timer(1);
+#ifdef CONFIG_UML_REAL_TIME_CLOCK
nsecs = get_time();
+#else
+ nsecs = (unsigned long long) xtime.tv_sec * BILLION + xtime.tv_nsec +
+ BILLION / HZ;
+#endif
xtime.tv_sec = nsecs / NSEC_PER_SEC;
xtime.tv_nsec = nsecs - xtime.tv_sec * NSEC_PER_SEC;
@@ -127,13 +132,18 @@
nsecs = os_nsecs();
set_normalized_timespec(&wall_to_monotonic, -nsecs / BILLION,
-nsecs % BILLION);
+ set_normalized_timespec(&xtime, nsecs / BILLION, nsecs % BILLION);
late_time_init = register_timer;
}
void do_gettimeofday(struct timeval *tv)
{
+#ifdef CONFIG_UML_REAL_TIME_CLOCK
unsigned long long nsecs = get_time();
-
+#else
+ unsigned long long nsecs = (unsigned long long) xtime.tv_sec * BILLION +
+ xtime.tv_nsec;
+#endif
tv->tv_sec = nsecs / NSEC_PER_SEC;
/* Careful about calculations here - this was originally done as
* (nsecs - tv->tv_sec * NSEC_PER_SEC) / NSEC_PER_USEC