Commit b7ec15bd authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds

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: default avatarJeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 83ff7df5
...@@ -34,8 +34,8 @@ unsigned long long sched_clock(void) ...@@ -34,8 +34,8 @@ unsigned long long sched_clock(void)
return (unsigned long long)jiffies_64 * (1000000000 / HZ); return (unsigned long long)jiffies_64 * (1000000000 / HZ);
} }
static unsigned long long prev_nsecs[NR_CPUS];
#ifdef CONFIG_UML_REAL_TIME_CLOCK #ifdef CONFIG_UML_REAL_TIME_CLOCK
static unsigned long long prev_nsecs[NR_CPUS];
static long long delta[NR_CPUS]; /* Deviation per interval */ static long long delta[NR_CPUS]; /* Deviation per interval */
#endif #endif
...@@ -94,7 +94,12 @@ irqreturn_t um_timer(int irq, void *dev) ...@@ -94,7 +94,12 @@ irqreturn_t um_timer(int irq, void *dev)
do_timer(1); do_timer(1);
#ifdef CONFIG_UML_REAL_TIME_CLOCK
nsecs = get_time(); 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_sec = nsecs / NSEC_PER_SEC;
xtime.tv_nsec = nsecs - xtime.tv_sec * NSEC_PER_SEC; xtime.tv_nsec = nsecs - xtime.tv_sec * NSEC_PER_SEC;
...@@ -127,13 +132,18 @@ void time_init(void) ...@@ -127,13 +132,18 @@ void time_init(void)
nsecs = os_nsecs(); nsecs = os_nsecs();
set_normalized_timespec(&wall_to_monotonic, -nsecs / BILLION, set_normalized_timespec(&wall_to_monotonic, -nsecs / BILLION,
-nsecs % BILLION); -nsecs % BILLION);
set_normalized_timespec(&xtime, nsecs / BILLION, nsecs % BILLION);
late_time_init = register_timer; late_time_init = register_timer;
} }
void do_gettimeofday(struct timeval *tv) void do_gettimeofday(struct timeval *tv)
{ {
#ifdef CONFIG_UML_REAL_TIME_CLOCK
unsigned long long nsecs = get_time(); 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; tv->tv_sec = nsecs / NSEC_PER_SEC;
/* Careful about calculations here - this was originally done as /* Careful about calculations here - this was originally done as
* (nsecs - tv->tv_sec * NSEC_PER_SEC) / NSEC_PER_USEC * (nsecs - tv->tv_sec * NSEC_PER_SEC) / NSEC_PER_USEC
......
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