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| author | Peter Zijlstra <peterz@infradead.org> | 2017-03-17 12:48:18 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-03-23 07:31:49 +0100 |
| commit | 698eff6355f735d46d1b7113df8b422874cd7988 (patch) | |
| tree | 77a7207a64ac5c8b87844bc4e91f551bf4102275 /kernel | |
| parent | 71fdb70eb48784c1f28cdf2e67c4c587dd7f2594 (diff) | |
| download | linux-698eff6355f735d46d1b7113df8b422874cd7988.tar.bz2 | |
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>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/clock.c | 22 |
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; |