hrtimers: Reorder clock bases

The ordering of the clock bases is historical due to the
CLOCK_REALTIME and CLOCK_MONOTONIC constants. Now the hrtimer bases
have their own enumeration due to the gap between CLOCK_MONOTONIC and
CLOCK_BOOTTIME. So we can be more clever as most timers end up on the
CLOCK_MONOTONIC base due to the virtue of POSIX declaring that
relative CLOCK_REALTIME timers are not affected by time changes. In
desktop environments this is slowly changing as applications switch to
absolute timers, but I've observed empty CLOCK_REALTIME bases often
enough. There is no performance penalty or overhead when
CLOCK_REALTIME timers are active, but in case they are not we don't
skip over a full cache line.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 771c95802edc..51932e5acf7c 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -153,8 +153,8 @@ struct hrtimer_clock_base {
 };
 
 enum  hrtimer_base_type {
-        HRTIMER_BASE_REALTIME,
         HRTIMER_BASE_MONOTONIC,
+        HRTIMER_BASE_REALTIME,
         HRTIMER_BASE_BOOTTIME,
         HRTIMER_MAX_CLOCK_BASES,
 };