From 17c38b7490b3f0300c7812aefdae2ddda7ab4112 Mon Sep 17 00:00:00 2001 From: john stultz Date: Tue, 24 Jul 2007 18:38:34 -0700 Subject: Cache xtime every call to update_wall_time This avoids xtime lag seen with dynticks, because while 'xtime' itself is still not updated often, we keep a 'xtime_cache' variable around that contains the approximate real-time that _is_ updated each time we do a 'update_wall_time()', and is thus never off by more than one tick. IOW, this restores the original semantics for 'xtime' users, as long as you use the proper abstraction functions (ie 'current_kernel_time()' or 'get_seconds()' depending on whether you want a timespec or just the seconds field). [ Updated Patch. As penance for my sins I've also yanked another #ifdef that was added to avoid the xtime lag w/ hrtimers. ] Signed-off-by: John Stultz Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Linus Torvalds --- kernel/hrtimer.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'kernel/hrtimer.c') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index a7bb05e6cb63..c21ca6bfaa66 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -141,11 +141,7 @@ static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) do { seq = read_seqbegin(&xtime_lock); -#ifdef CONFIG_NO_HZ - getnstimeofday(&xts); -#else xts = current_kernel_time(); -#endif tom = wall_to_monotonic; } while (read_seqretry(&xtime_lock, seq)); -- cgit v1.2.3