perf_counter tools: Provide helper to print percents color

Among perf annotate, perf report and perf top, we can find the
common colored printing of percents according to the following
rules:

    High overhead =  > 5%, colored in red
    Mid overhead =  > 0.5%, colored in green
    Low overhead =  < 0.5%, default color

Factorize these multiple checks in a single function named
percent_color_fprintf() and also provide a get_percent_color()
for sites which print percentages and other things at the same
time.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1246558475-10624-2-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/util/color.h b/tools/perf/util/color.h
index 5abfd37..706cec5 100644
--- a/tools/perf/util/color.h
+++ b/tools/perf/util/color.h
@@ -15,6 +15,9 @@
 #define PERF_COLOR_CYAN		"\033[36m"
 #define PERF_COLOR_BG_RED	"\033[41m"
 
+#define MIN_GREEN	0.5
+#define MIN_RED		5.0
+
 /*
  * This variable stores the value of color.ui
  */
@@ -32,5 +35,7 @@
 int color_fprintf(FILE *fp, const char *color, const char *fmt, ...);
 int color_fprintf_ln(FILE *fp, const char *color, const char *fmt, ...);
 int color_fwrite_lines(FILE *fp, const char *color, size_t count, const char *buf);
+int percent_color_fprintf(FILE *fp, const char *fmt, double percent);
+char *get_percent_color(double percent);
 
 #endif /* COLOR_H */