[RFC patch 02/15] get_cycles() : x86 HAVE_GET_CYCLES

Mathieu Desnoyers
2008-10-16T23:27:31Z

[-- Attachment #1: get-cycles-x86-have-get-cycles.patch --]
[-- Type: text/plain, Size: 1904 bytes --]

This patch selects HAVE_GET_CYCLES and makes sure get_cycles_barrier() and
get_cycles_rate() are implemented.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: David Miller <davem@davemloft.net>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Ingo Molnar <mingo@redhat.com>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: linux-arch@vger.kernel.org
---
arch/x86/Kconfig | 1 +
include/asm-x86/tsc.h | 12 ++++++++++++
2 files changed, 13 insertions(+)

Index: linux-2.6-lttng/arch/x86/Kconfig
===================================================================
--- linux-2.6-lttng.orig/arch/x86/Kconfig 2008-10-16 13:07:04.000000000 -0400
+++ linux-2.6-lttng/arch/x86/Kconfig 2008-10-16 13:07:12.000000000 -0400
@@ -19,6 +19,7 @@ config X86_64
config X86
def_bool y
select HAVE_UNSTABLE_SCHED_CLOCK
+ select HAVE_GET_CYCLES
select HAVE_IDE
select HAVE_OPROFILE
select HAVE_IOREMAP_PROT
Index: linux-2.6-lttng/include/asm-x86/tsc.h
===================================================================
--- linux-2.6-lttng.orig/include/asm-x86/tsc.h 2008-10-16 13:07:04.000000000 -0400
+++ linux-2.6-lttng/include/asm-x86/tsc.h 2008-10-16 13:07:24.000000000 -0400
@@ -50,6 +50,18 @@ extern void mark_tsc_unstable(char *reas
extern int unsynchronized_tsc(void);
int check_tsc_unstable(void);

+static inline cycles_t get_cycles_rate(void)
+{
+ if (check_tsc_unstable())
+ return 0;
+ return tsc_khz;
+}
+
+static inline void get_cycles_barrier(void)
+{
+ rdtsc_barrier();
+}
+
/*
* Boot-time check whether the TSCs are synchronized across
* all CPUs/cores:

--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal