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authorAdrian Hunter <adrian.hunter@intel.com>2013-06-28 16:22:18 +0300
committerIngo Molnar <mingo@kernel.org>2013-07-23 12:17:45 +0200
commitc73deb6aecda2955716f31572516f09d930ef450 (patch)
tree037f7945cb4289545d5ffbe9506e071a83d6c1a6 /arch/x86/include/asm/tsc.h
parent860f085b74e9f0075de8140ed3a1e5b5e3e39aa8 (diff)
perf/x86: Add ability to calculate TSC from perf sample timestamps
For modern CPUs, perf clock is directly related to TSC. TSC can be calculated from perf clock and vice versa using a simple calculation. Two of the three componenets of that calculation are already exported in struct perf_event_mmap_page. This patch exports the third. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "H. Peter Anvin" <hpa@zytor.com> Link: http://lkml.kernel.org/r/1372425741-1676-3-git-send-email-adrian.hunter@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/tsc.h')
-rw-r--r--arch/x86/include/asm/tsc.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h
index c91e8b9d588b..235be70d5bb4 100644
--- a/arch/x86/include/asm/tsc.h
+++ b/arch/x86/include/asm/tsc.h
@@ -49,6 +49,7 @@ extern void tsc_init(void);
extern void mark_tsc_unstable(char *reason);
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 int tsc_clocksource_reliable;