@John Stultz I also backported this patch to 2.6.31.2-rt13, could you please look it over and see if it looks okay to you? @Thomas Same as the previous patch, please consider queuing this for -rt14 and we can drop it in the future because John Stultz submitted it upstream. Thanks >From 868ee3f7346a90ae3b529ac24996f059cc322a82 Mon Sep 17 00:00:00 2001 From: tip-bot for john stultz <johnstul@xxxxxxxxxx> Date: Mon, 5 Oct 2009 11:54:53 +0000 Subject: [PATCH] time: Remove xtime_cache Commit-ID: 7bc7d637452383d56ba4368d4336b0dde1bb476d Gitweb: http://git.kernel.org/tip/7bc7d637452383d56ba4368d4336b0dde1bb476d Author: john stultz <johnstul@xxxxxxxxxx> AuthorDate: Fri, 2 Oct 2009 16:24:15 -0700 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Mon, 5 Oct 2009 13:52:02 +0200 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@xxxxxxxxxx> Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Reviewed-by: John Kacur <jkacur@xxxxxxxxxx> Cc: Clark Williams <williams@xxxxxxxxxx> Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> LKML-Reference: <1254525855.7741.95.camel@xxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> Signed-off-by: John Kacur <jkacur@xxxxxxxxxx> --- kernel/time.c | 1 - kernel/time/timekeeping.c | 20 ++------------------ 2 files changed, 2 insertions(+), 19 deletions(-) diff --git a/kernel/time.c b/kernel/time.c index 35d1aaa..01944b5 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -136,7 +136,6 @@ static inline void warp_clock(void) write_atomic_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_atomic_sequnlock_irq(&xtime_lock); clock_was_set(); } diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 4630874..4a0920d 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -48,16 +48,8 @@ static unsigned long total_sleep_time; /* seconds */ /* 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); -} - struct clocksource *clock; - #ifdef CONFIG_GENERIC_TIME /** * clocksource_forward_now - update clock to the current time @@ -233,7 +225,6 @@ int do_settimeofday(struct timespec *tv) xtime = *tv; - update_xtime_cache(0); clock->error = 0; ntp_clear(); @@ -435,7 +426,6 @@ void __init timekeeping_init(void) xtime.tv_nsec = 0; set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec); - update_xtime_cache(0); total_sleep_time = 0; write_atomic_sequnlock_irqrestore(&xtime_lock, flags); } @@ -467,7 +457,6 @@ static int timekeeping_resume(struct sys_device *dev) wall_to_monotonic.tv_sec -= sleep_length; total_sleep_time += sleep_length; } - update_xtime_cache(0); /* re-base the last cycle value */ clock->cycle_last = 0; clock->cycle_last = clocksource_read(clock); @@ -608,7 +597,6 @@ static void clocksource_adjust(s64 offset) (NTP_SCALE_SHIFT - clock->shift); } - /** * logarithmic_accumulation - shifted accumulation of cycles * @@ -652,7 +640,6 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) return offset; } - /** * update_wall_time - Uses the current clocksource to increment the wall time * @@ -661,7 +648,6 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) void update_wall_time(void) { cycle_t offset; - u64 nsecs; int shift = 0, maxshift; /* Make sure we're fully resumed: */ @@ -725,8 +711,6 @@ void update_wall_time(void) clock->xtime_nsec -= (s64)xtime.tv_nsec << clock->shift; clock->error += clock->xtime_nsec << (NTP_SCALE_SHIFT - clock->shift); - update_xtime_cache(cyc2ns(clock, offset)); - /* check to see if there is a new clocksource to use */ change_clocksource(); update_vsyscall(&xtime, clock); @@ -761,7 +745,7 @@ 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); @@ -774,7 +758,7 @@ struct timespec current_kernel_time(void) do { seq = read_atomic_seqbegin(&xtime_lock); - now = xtime_cache; + now = xtime; } while (read_atomic_seqretry(&xtime_lock, seq)); return now; -- 1.6.0.6 -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
