Revert "sched_clock: prevent scd->clock from moving backwards"

This reverts commit 5b7dba4ff834259a5623e03a565748704a8fe449, which
caused a regression in hibernate, reported by and bisected by Fabio
Comolli.

This revert fixes

 http://bugzilla.kernel.org/show_bug.cgi?id=12155
 http://bugzilla.kernel.org/show_bug.cgi?id=12149

Bisected-by: Fabio Comolli <fabio.comolli@gmail.com>
Requested-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
index 8178724..e8ab096 100644 (file)
--- a/kernel/sched_clock.c
+++ b/kernel/sched_clock.c
@@ -118,13 +118,13 @@ static u64 __update_sched_clock(struct sched_clock_data *scd, u64 now)
 
        /*
         * scd->clock = clamp(scd->tick_gtod + delta,
-        *                    max(scd->tick_gtod, scd->clock),
-        *                    max(scd->clock, scd->tick_gtod + TICK_NSEC));
+        *                    max(scd->tick_gtod, scd->clock),
+        *                    scd->tick_gtod + TICK_NSEC);
         */
 
        clock = scd->tick_gtod + delta;
        min_clock = wrap_max(scd->tick_gtod, scd->clock);
-       max_clock = wrap_max(scd->clock, scd->tick_gtod + TICK_NSEC);
+       max_clock = scd->tick_gtod + TICK_NSEC;
 
        clock = wrap_max(clock, min_clock);
        clock = wrap_min(clock, max_clock);