[PATCH 01/11] perf/x86: Fix native_perf_sched_clock_from_tsc() with __sched_clock_offset

From: Adrian Hunter
Date: Wed Feb 09 2022 - 07:00:14 EST


native_perf_sched_clock_from_tsc() is used to produce a time value that can
be consistent with perf_clock(). Consequently, it should be adjusted by
__sched_clock_offset, the same as perf_clock() would be.

Fixes: 698eff6355f735 ("sched/clock, x86/perf: Fix perf test tsc")
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
arch/x86/kernel/tsc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index a698196377be..c1c73fe324cd 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -242,7 +242,8 @@ u64 native_sched_clock(void)
*/
u64 native_sched_clock_from_tsc(u64 tsc)
{
- return cycles_2_ns(tsc);
+ return cycles_2_ns(tsc) +
+ (sched_clock_stable() ? __sched_clock_offset : 0);
}

/* We need to define a real function for sched_clock, to override the
--
2.25.1