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authorAndi Kleen2015-05-10 12:22:39 -0700
committerIngo Molnar2015-08-04 10:16:55 +0200
commita94cab2376cb35f236be14e2833cef63a8762a31 (patch)
tree666ded02a83b67d8772bc771d61dd6d1ae863f05 /arch/x86/kernel/tsc.c
parentb1bf72d6691cc33fc7763fc8ec77df42ca1a8702 (diff)
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>
Diffstat (limited to 'arch/x86/kernel/tsc.c')
-rw-r--r--arch/x86/kernel/tsc.c8
1 files changed, 8 insertions, 0 deletions
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