perf diff: Add ratio computation way to compare hist entries

Adding -c option to select computation method with the current 'Delta'
computation as default. Current possible values are of this option are:
'delta' and 'ratio'.

Adding 'ratio' as new computation way to compare hist entries.  If
specified the 'Ratio' column is displayed with value 'r' computed as:

  r = A->period / B->period

with:
  - A/B being matching hist entry from first/second file specified
    (or perf.data/perf.data.old) respectively.
  - period being the hist entry period value

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1349448287-18919-3-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/tools/perf/ui/hist.c b/tools/perf/ui/hist.c
index f5a1e4f65263..1b633a4b5c45 100644
--- a/tools/perf/ui/hist.c
+++ b/tools/perf/ui/hist.c
@@ -266,6 +266,33 @@ static int hpp__entry_delta(struct perf_hpp *hpp, struct hist_entry *he)
         return scnprintf(hpp->buf, hpp->size, fmt, buf);
 }
 
+static int hpp__header_ratio(struct perf_hpp *hpp)
+{
+        const char *fmt = symbol_conf.field_sep ? "%s" : "%14s";
+
+        return scnprintf(hpp->buf, hpp->size, fmt, "Ratio");
+}
+
+static int hpp__width_ratio(struct perf_hpp *hpp __maybe_unused)
+{
+        return 14;
+}
+
+static int hpp__entry_ratio(struct perf_hpp *hpp, struct hist_entry *he)
+{
+        struct hist_entry *pair = he->pair;
+        double new_period = he->stat.period;
+        double old_period = pair ? pair->stat.period : 0;
+        double ratio = pair ? new_period / old_period : 0;
+        const char *fmt = symbol_conf.field_sep ? "%s" : "%14s";
+        char buf[32] = " ";
+
+        if (ratio > 0.0)
+                scnprintf(buf, sizeof(buf), "%+14.6F", ratio);
+
+        return scnprintf(hpp->buf, hpp->size, fmt, buf);
+}
+
 static int hpp__header_displ(struct perf_hpp *hpp)
 {
         return scnprintf(hpp->buf, hpp->size, "Displ.");
@@ -311,6 +338,7 @@ struct perf_hpp_fmt perf_hpp__format[] = {
         { .cond = false, HPP__PRINT_FNS(samples) },
         { .cond = false, HPP__PRINT_FNS(period) },
         { .cond = false, HPP__PRINT_FNS(delta) },
+        { .cond = false, HPP__PRINT_FNS(ratio) },
         { .cond = false, HPP__PRINT_FNS(displ) }
 };