perf report: Calculate the average cycles of iterations

The branch history code has a loop detection function. With this, we can
get the number of iterations by calculating the removed loops.

While it would be nice for knowing the average cycles of iterations.
This patch adds up the cycles in branch entries of removed loops and
save the result to the next branch entry (e.g. branch entry A).

Finally it will display the iteration number and average cycles at the
"from" of branch entry A.

For example:
perf record -g -j any,save_type ./div
perf report --branch-history --no-children --stdio

--22.63%--main div.c:42 (RET CROSS_2M)
          compute_flag div.c:28 (cycles:2 iter:173115 avg_cycles:2)
          |
           --10.73%--compute_flag div.c:27 (RET CROSS_2M)
                     rand rand.c:28 (cycles:1)
                     rand rand.c:28 (RET CROSS_2M)
                     __random random.c:298 (cycles:1)
                     __random random.c:297 (COND_BWD CROSS_2M)
                     __random random.c:295 (cycles:1)
                     __random random.c:295 (COND_BWD CROSS_2M)
                     __random random.c:295 (cycles:1)
                     __random random.c:295 (RET CROSS_2M)

Signed-off-by: Yao Jin <yao.jin@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1502111115-18305-1-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Jin Yao
2017-08-07 21:05:15 +08:00
committed by Arnaldo Carvalho de Melo
parent 1b2f76d77a
commit c4ee06251d
5 changed files with 85 additions and 79 deletions

View File

@@ -124,12 +124,8 @@ static size_t ipchain__fprintf_graph(FILE *fp, struct callchain_node *node,
str = callchain_list__sym_name(chain, bf, sizeof(bf), false);
if (symbol_conf.show_branchflag_count) {
if (!period)
callchain_list_counts__printf_value(node, chain, NULL,
buf, sizeof(buf));
else
callchain_list_counts__printf_value(NULL, chain, NULL,
buf, sizeof(buf));
callchain_list_counts__printf_value(chain, NULL,
buf, sizeof(buf));
if (asprintf(&alloc_str, "%s%s", str, buf) < 0)
str = "Not enough memory!";
@@ -313,7 +309,7 @@ static size_t callchain__fprintf_graph(FILE *fp, struct rb_root *root,
if (symbol_conf.show_branchflag_count)
ret += callchain_list_counts__printf_value(
NULL, chain, fp, NULL, 0);
chain, fp, NULL, 0);
ret += fprintf(fp, "\n");
if (++entries_printed == callchain_param.print_limit)