Messages in this thread Patch in this message | | | Date | Tue, 4 Aug 2015 01:55:58 -0700 | From | tip-bot for Andi Kleen <> | Subject | [tip:perf/core] perf/x86: Add a native_perf_sched_clock_from_tsc( ) |
| |
Commit-ID: a94cab2376cb35f236be14e2833cef63a8762a31 Gitweb: http://git.kernel.org/tip/a94cab2376cb35f236be14e2833cef63a8762a31 Author: Andi Kleen <ak@linux.intel.com> AuthorDate: Sun, 10 May 2015 12:22:39 -0700 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Tue, 4 Aug 2015 10:16:55 +0200
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 <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: eranian@google.com Link: http://lkml.kernel.org/r/1431285767-27027-2-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org> --- 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 7437b41..88e9a38 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
| |