perf diff: Add -F option to display formula for computation

Adding -F option to display the formula for specified computation.

This is mainly to facilitate debugging, but can be useful anyway.

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/1349448287-18919-7-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 66 insertions, 1 deletions

diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 2411dd18c556..dd9c064514f2 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -25,6 +25,7 @@ static char	  diff__default_sort_order[] = "dso,symbol";
 static bool  force;
 static bool show_displacement;
 static bool show_period;
+static bool show_formula;
 static bool show_baseline_only;
 static bool sort_compute;
 
@@ -190,6 +191,62 @@ s64 perf_diff__compute_wdiff(struct hist_entry *he)
         return he->diff.wdiff;
 }
 
+static int formula_delta(struct hist_entry *he, char *buf, size_t size)
+{
+        struct hist_entry *pair = he->pair;
+
+        if (!pair)
+                return -1;
+
+        return scnprintf(buf, size,
+                         "(%" PRIu64 " * 100 / %" PRIu64 ") - "
+                         "(%" PRIu64 " * 100 / %" PRIu64 ")",
+                          he->stat.period, he->hists->stats.total_period,
+                          pair->stat.period, pair->hists->stats.total_period);
+}
+
+static int formula_ratio(struct hist_entry *he, char *buf, size_t size)
+{
+        struct hist_entry *pair = he->pair;
+        double new_period = he->stat.period;
+        double old_period = pair ? pair->stat.period : 0;
+
+        if (!pair)
+                return -1;
+
+        return scnprintf(buf, size, "%.0F / %.0F", new_period, old_period);
+}
+
+static int formula_wdiff(struct hist_entry *he, char *buf, size_t size)
+{
+        struct hist_entry *pair = he->pair;
+        u64 new_period = he->stat.period;
+        u64 old_period = pair ? pair->stat.period : 0;
+
+        if (!pair)
+                return -1;
+
+        return scnprintf(buf, size,
+                  "(%" PRIu64 " * " "%" PRId64 ") - (%" PRIu64 " * " "%" PRId64 ")",
+                  new_period, compute_wdiff_w2, old_period, compute_wdiff_w1);
+}
+
+int perf_diff__formula(char *buf, size_t size, struct hist_entry *he)
+{
+        switch (compute) {
+        case COMPUTE_DELTA:
+                return formula_delta(he, buf, size);
+        case COMPUTE_RATIO:
+                return formula_ratio(he, buf, size);
+        case COMPUTE_WEIGHTED_DIFF:
+                return formula_wdiff(he, buf, size);
+        default:
+                BUG_ON(1);
+        }
+
+        return -1;
+}
+
 static int hists__add_entry(struct hists *self,
                             struct addr_location *al, u64 period)
 {
@@ -543,6 +600,8 @@ static const struct option options[] = {
                      setup_compute),
         OPT_BOOLEAN('p', "period", &show_period,
                     "Show period values."),
+        OPT_BOOLEAN('F', "formula", &show_formula,
+                    "Show formula."),
         OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
                     "dump raw trace in ASCII"),
         OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
@@ -571,7 +630,10 @@ static void ui_init(void)
         /* No overhead column. */
         perf_hpp__column_enable(PERF_HPP__OVERHEAD, false);
 
-        /* Display baseline/delta/ratio/displacement/periods columns. */
+        /*
+         * Display baseline/delta/ratio/displacement/
+         * formula/periods columns.
+         */
         perf_hpp__column_enable(PERF_HPP__BASELINE, true);
 
         switch (compute) {
@@ -591,6 +653,9 @@ static void ui_init(void)
         if (show_displacement)
                 perf_hpp__column_enable(PERF_HPP__DISPL, true);
 
+        if (show_formula)
+                perf_hpp__column_enable(PERF_HPP__FORMULA, true);
+
         if (show_period) {
                 perf_hpp__column_enable(PERF_HPP__PERIOD, true);
                 perf_hpp__column_enable(PERF_HPP__PERIOD_BASELINE, true);