From: Andi Kleen <[email protected]> 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.
Right now I ignore paravirt for this. It will just get the native clock. But there isn't para virtualized PEBS anyways. Cc: [email protected] Signed-off-by: Andi Kleen <[email protected]> --- 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 94605c0..aad56eb 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 5054497..c16afd5 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 -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
