sched/clock, x86/perf: Fix "perf test tsc"

People reported that commit:

  5680d8094ffa ("sched/clock: Provide better clock continuity")

broke "perf test tsc".

That commit added another offset to the reported clock value; so
take that into account when computing the provided offset values.

Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 5680d8094ffa ("sched/clock: Provide better clock continuity")
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 11 insertions, 11 deletions

diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index fec0f58c8dee..24a3e01bf8cb 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -96,10 +96,10 @@ static DEFINE_STATIC_KEY_FALSE(__sched_clock_stable);
 static int __sched_clock_stable_early = 1;
 
 /*
- * We want: ktime_get_ns() + gtod_offset == sched_clock() + raw_offset
+ * We want: ktime_get_ns() + __gtod_offset == sched_clock() + __sched_clock_offset
  */
-static __read_mostly u64 raw_offset;
-static __read_mostly u64 gtod_offset;
+__read_mostly u64 __sched_clock_offset;
+static __read_mostly u64 __gtod_offset;
 
 struct sched_clock_data {
         u64                     tick_raw;
@@ -131,11 +131,11 @@ static void __set_sched_clock_stable(void)
         /*
          * Attempt to make the (initial) unstable->stable transition continuous.
          */
-        raw_offset = (scd->tick_gtod + gtod_offset) - (scd->tick_raw);
+        __sched_clock_offset = (scd->tick_gtod + __gtod_offset) - (scd->tick_raw);
 
         printk(KERN_INFO "sched_clock: Marking stable (%lld, %lld)->(%lld, %lld)\n",
-                        scd->tick_gtod, gtod_offset,
-                        scd->tick_raw,  raw_offset);
+                        scd->tick_gtod, __gtod_offset,
+                        scd->tick_raw,  __sched_clock_offset);
 
         static_branch_enable(&__sched_clock_stable);
         tick_dep_clear(TICK_DEP_BIT_CLOCK_UNSTABLE);
@@ -161,11 +161,11 @@ static void __clear_sched_clock_stable(void)
          *
          * Still do what we can.
          */
-        gtod_offset = (scd->tick_raw + raw_offset) - (scd->tick_gtod);
+        __gtod_offset = (scd->tick_raw + __sched_clock_offset) - (scd->tick_gtod);
 
         printk(KERN_INFO "sched_clock: Marking unstable (%lld, %lld)<-(%lld, %lld)\n",
-                        scd->tick_gtod, gtod_offset,
-                        scd->tick_raw,  raw_offset);
+                        scd->tick_gtod, __gtod_offset,
+                        scd->tick_raw,  __sched_clock_offset);
 
         tick_dep_set(TICK_DEP_BIT_CLOCK_UNSTABLE);
 
@@ -238,7 +238,7 @@ again:
          *                    scd->tick_gtod + TICK_NSEC);
          */
 
-        clock = scd->tick_gtod + gtod_offset + delta;
+        clock = scd->tick_gtod + __gtod_offset + delta;
         min_clock = wrap_max(scd->tick_gtod, old_clock);
         max_clock = wrap_max(old_clock, scd->tick_gtod + TICK_NSEC);
 
@@ -324,7 +324,7 @@ u64 sched_clock_cpu(int cpu)
         u64 clock;
 
         if (sched_clock_stable())
-                return sched_clock() + raw_offset;
+                return sched_clock() + __sched_clock_offset;
 
         if (unlikely(!sched_clock_running))
                 return 0ull;