diff options
author | john stultz <johnstul@us.ibm.com> | 2009-10-02 16:24:15 -0700 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2009-10-05 13:52:02 +0200 |
commit | 7bc7d637452383d56ba4368d4336b0dde1bb476d (patch) | |
tree | f1c8e1e103a900850342d46de27ebdf1e7d07f78 | |
parent | a092ff0f90cae22b2ac8028ecd2c6f6c1a9e4601 (diff) | |
download | linux-7bc7d637452383d56ba4368d4336b0dde1bb476d.tar.bz2 |
time: Remove xtime_cache
With the prior logarithmic time accumulation patch, xtime will now
always be within one "tick" of the current time, instead of
possibly half a second off.
This removes the need for the xtime_cache value, which always
stored the time at the last interrupt, so this patch cleans that up
removing the xtime_cache related code.
This is a bit simpler, but still could use some wider testing.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: John Kacur <jkacur@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1254525855.7741.95.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r-- | kernel/time.c | 1 | ||||
-rw-r--r-- | kernel/time/timekeeping.c | 27 |
2 files changed, 4 insertions, 24 deletions
diff --git a/kernel/time.c b/kernel/time.c index 2e2e469a7fec..2ef4fe2079b6 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -136,7 +136,6 @@ static inline void warp_clock(void) write_seqlock_irq(&xtime_lock); wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60; xtime.tv_sec += sys_tz.tz_minuteswest * 60; - update_xtime_cache(0); write_sequnlock_irq(&xtime_lock); clock_was_set(); } diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 5fdd78e0858a..96b3f0dfa5dc 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -164,13 +164,6 @@ struct timespec raw_time; /* flag for if timekeeping is suspended */ int __read_mostly timekeeping_suspended; -static struct timespec xtime_cache __attribute__ ((aligned (16))); -void update_xtime_cache(u64 nsec) -{ - xtime_cache = xtime; - timespec_add_ns(&xtime_cache, nsec); -} - /* must hold xtime_lock */ void timekeeping_leap_insert(int leapsecond) { @@ -331,8 +324,6 @@ int do_settimeofday(struct timespec *tv) xtime = *tv; - update_xtime_cache(0); - timekeeper.ntp_error = 0; ntp_clear(); @@ -547,7 +538,6 @@ void __init timekeeping_init(void) } set_normalized_timespec(&wall_to_monotonic, -boot.tv_sec, -boot.tv_nsec); - update_xtime_cache(0); total_sleep_time.tv_sec = 0; total_sleep_time.tv_nsec = 0; write_sequnlock_irqrestore(&xtime_lock, flags); @@ -581,7 +571,6 @@ static int timekeeping_resume(struct sys_device *dev) wall_to_monotonic = timespec_sub(wall_to_monotonic, ts); total_sleep_time = timespec_add_safe(total_sleep_time, ts); } - update_xtime_cache(0); /* re-base the last cycle value */ timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); timekeeper.ntp_error = 0; @@ -721,7 +710,6 @@ static void timekeeping_adjust(s64 offset) timekeeper.ntp_error_shift; } - /** * logarithmic_accumulation - shifted accumulation of cycles * @@ -765,7 +753,6 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) return offset; } - /** * update_wall_time - Uses the current clocksource to increment the wall time * @@ -775,7 +762,6 @@ void update_wall_time(void) { struct clocksource *clock; cycle_t offset; - u64 nsecs; int shift = 0, maxshift; /* Make sure we're fully resumed: */ @@ -841,9 +827,6 @@ void update_wall_time(void) timekeeper.ntp_error += timekeeper.xtime_nsec << timekeeper.ntp_error_shift; - nsecs = clocksource_cyc2ns(offset, timekeeper.mult, timekeeper.shift); - update_xtime_cache(nsecs); - /* check to see if there is a new clocksource to use */ update_vsyscall(&xtime, timekeeper.clock); } @@ -880,13 +863,13 @@ void monotonic_to_bootbased(struct timespec *ts) unsigned long get_seconds(void) { - return xtime_cache.tv_sec; + return xtime.tv_sec; } EXPORT_SYMBOL(get_seconds); struct timespec __current_kernel_time(void) { - return xtime_cache; + return xtime; } struct timespec current_kernel_time(void) @@ -896,8 +879,7 @@ struct timespec current_kernel_time(void) do { seq = read_seqbegin(&xtime_lock); - - now = xtime_cache; + now = xtime; } while (read_seqretry(&xtime_lock, seq)); return now; @@ -911,8 +893,7 @@ struct timespec get_monotonic_coarse(void) do { seq = read_seqbegin(&xtime_lock); - - now = xtime_cache; + now = xtime; mono = wall_to_monotonic; } while (read_seqretry(&xtime_lock, seq)); |