From a94cab2376cb35f236be14e2833cef63a8762a31 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Sun, 10 May 2015 12:22:39 -0700 Subject: [PATCH] perf/x86: Add a native_perf_sched_clock_from_tsc() PEBSv3 has a raw TSC time stamp in its memory buffer that later needs to to be converted to perf_clock. Add a native_sched_clock_from_tsc() that works the same as native_sched_clock(), but starts with an already given TSC value. Paravirt is ignored, it will just get the native clock. But there isn't a para virtualized PEBS anyway. Signed-off-by: Andi Kleen Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: eranian@google.com Link: http://lkml.kernel.org/r/1431285767-27027-2-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar --- arch/x86/include/asm/tsc.h | 1 + arch/x86/kernel/tsc.c | 8 ++++++++ 2 files changed, 9 insertions(+) diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h index 94605c0e9cee..aad56eb3bbe2 100644 --- a/arch/x86/include/asm/tsc.h +++ b/arch/x86/include/asm/tsc.h @@ -51,6 +51,7 @@ extern int unsynchronized_tsc(void); extern int check_tsc_unstable(void); extern int check_tsc_disabled(void); extern unsigned long native_calibrate_tsc(void); +extern unsigned long long native_sched_clock_from_tsc(u64 tsc); extern int tsc_clocksource_reliable; diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 7437b41f6a47..88e9a38c71a5 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -296,6 +296,14 @@ u64 native_sched_clock(void) return cycles_2_ns(tsc_now); } +/* + * Generate a sched_clock if you already have a TSC value. + */ +u64 native_sched_clock_from_tsc(u64 tsc) +{ + return cycles_2_ns(tsc); +} + /* We need to define a real function for sched_clock, to override the weak default version */ #ifdef CONFIG_PARAVIRT