perf diff: Start moving to support matching more than two hists

We want to match more than two hists, so that we can match more than two
perf.data files and moreover, match hist_entries (buckets) in multiple
events in a group.

So the "baseline"/"leader" will instead of a ->pair pointer, use a
list_head, that will link to the pairs and hists__match use it.

Following that perf_evlist__link will link the hists in its evsel
groups.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-2kbmzepoi544ygj9godseqpv@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 12 insertions, 9 deletions

diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 380683de1df3..8a9db38e562f 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -154,7 +154,7 @@ static double get_period_percent(struct hist_entry *he, u64 period)
 
 double perf_diff__compute_delta(struct hist_entry *he)
 {
-        struct hist_entry *pair = he->pair;
+        struct hist_entry *pair = hist_entry__next_pair(he);
         double new_percent = get_period_percent(he, he->stat.period);
         double old_percent = pair ? get_period_percent(pair, pair->stat.period) : 0.0;
 
@@ -165,7 +165,7 @@ double perf_diff__compute_delta(struct hist_entry *he)
 
 double perf_diff__compute_ratio(struct hist_entry *he)
 {
-        struct hist_entry *pair = he->pair;
+        struct hist_entry *pair = hist_entry__next_pair(he);
         double new_period = he->stat.period;
         double old_period = pair ? pair->stat.period : 0;
 
@@ -176,7 +176,7 @@ double perf_diff__compute_ratio(struct hist_entry *he)
 
 s64 perf_diff__compute_wdiff(struct hist_entry *he)
 {
-        struct hist_entry *pair = he->pair;
+        struct hist_entry *pair = hist_entry__next_pair(he);
         u64 new_period = he->stat.period;
         u64 old_period = pair ? pair->stat.period : 0;
 
@@ -193,7 +193,7 @@ s64 perf_diff__compute_wdiff(struct hist_entry *he)
 
 static int formula_delta(struct hist_entry *he, char *buf, size_t size)
 {
-        struct hist_entry *pair = he->pair;
+        struct hist_entry *pair = hist_entry__next_pair(he);
 
         if (!pair)
                 return -1;
@@ -207,7 +207,7 @@ static int formula_delta(struct hist_entry *he, char *buf, size_t size)
 
 static int formula_ratio(struct hist_entry *he, char *buf, size_t size)
 {
-        struct hist_entry *pair = he->pair;
+        struct hist_entry *pair = hist_entry__next_pair(he);
         double new_period = he->stat.period;
         double old_period = pair ? pair->stat.period : 0;
 
@@ -219,7 +219,7 @@ static int formula_ratio(struct hist_entry *he, char *buf, size_t size)
 
 static int formula_wdiff(struct hist_entry *he, char *buf, size_t size)
 {
-        struct hist_entry *pair = he->pair;
+        struct hist_entry *pair = hist_entry__next_pair(he);
         u64 new_period = he->stat.period;
         u64 old_period = pair ? pair->stat.period : 0;
 
@@ -359,8 +359,11 @@ static void hists__match(struct hists *older, struct hists *newer)
         struct rb_node *nd;
 
         for (nd = rb_first(&newer->entries); nd; nd = rb_next(nd)) {
-                struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node);
-                pos->pair = hists__find_entry(older, pos);
+                struct hist_entry *pos = rb_entry(nd, struct hist_entry, rb_node),
+                                  *pair = hists__find_entry(older, pos);
+
+                if (pair)
+                        hist__entry_add_pair(pos, pair);
         }
 }
 
@@ -402,7 +405,7 @@ static void hists__baseline_only(struct hists *hists)
                 struct hist_entry *he = rb_entry(next, struct hist_entry, rb_node);
 
                 next = rb_next(&he->rb_node);
-                if (!he->pair) {
+                if (!hist_entry__next_pair(he)) {
                         rb_erase(&he->rb_node, &hists->entries);
                         hist_entry__free(he);
                 }