[PATCH 14/15] perf report: Use srcline from callchain for hist entries

Arnaldo Carvalho de Melo
2017-10-25T16:01:18Z

This also removes the symbol name from the srcline column, more on this
below.

This ensures we use the correct srcline, which could originate from a
potentially inlined function. The hist entries used to query for the
srcline based purely on the IP, which leads to wrong results for inlined
entries.

Before:

~~~~~
perf report --inline -s srcline -g none --stdio
...
# Children Self Source:Line
# ........ ........ ..................................................................................................................................
#
94.23% 0.00% __libc_start_main+18446603487898210537
94.23% 0.00% _start+41
44.58% 0.00% main+100
44.58% 0.00% std::_Norm_helper<true>::_S_do_it<double>+100
44.58% 0.00% std::__complex_abs+100
44.58% 0.00% std::abs<double>+100
44.58% 0.00% std::norm<double>+100
36.01% 0.00% hypot+18446603487892193300
25.81% 0.00% main+41
25.81% 0.00% std::__detail::_Adaptor<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul>, double>::operator()+41
25.81% 0.00% std::uniform_real_distribution<double>::operator()<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul> >+41
25.75% 25.75% random.h:143
18.39% 0.00% main+57
18.39% 0.00% std::__detail::_Adaptor<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul>, double>::operator()+57
18.39% 0.00% std::uniform_real_distribution<double>::operator()<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul> >+57
13.80% 13.80% random.tcc:3330
5.64% 0.00% ??:0
4.13% 4.13% __hypot_finite+163
4.13% 0.00% __hypot_finite+18446603487892193443
...
~~~~~

After:

~~~~~
perf report --inline -s srcline -g none --stdio
...
# Children Self Source:Line
# ........ ........ ...........................................
#
94.30% 1.19% main.cpp:39
94.23% 0.00% __libc_start_main+18446603487898210537
94.23% 0.00% _start+41
48.44% 1.70% random.h:1823
48.44% 0.00% random.h:1814
46.74% 2.53% random.h:185
44.68% 0.10% complex:589
44.68% 0.00% complex:597
44.68% 0.00% complex:654
44.68% 0.00% complex:664
40.61% 13.80% random.tcc:3330
36.01% 0.00% hypot+18446603487892193300
26.81% 0.00% random.h:151
26.81% 0.00% random.h:332
25.75% 25.75% random.h:143
5.64% 0.00% ??:0
4.13% 4.13% __hypot_finite+163
4.13% 0.00% __hypot_finite+18446603487892193443
...
~~~~~

Note that this change removes the symbol from the source:line hist
column. If this information is desired, users should explicitly query
for it if needed. I.e. run this command instead:

~~~~~
perf report --inline -s sym,srcline -g none --stdio
...
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 1K of event 'cycles:uppp'
# Event count (approx.): 1381229476
#
# Children Self Symbol Source:Line
# ........ ........ ................................................................................................................................... ...........................................
#
94.30% 1.19% [.] main main.cpp:39
94.23% 0.00% [.] __libc_start_main __libc_start_main+18446603487898210537
94.23% 0.00% [.] _start _start+41
48.44% 0.00% [.] std::uniform_real_distribution<double>::operator()<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul> > (inlined) random.h:1814
48.44% 0.00% [.] std::uniform_real_distribution<double>::operator()<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul> > (inlined) random.h:1823
46.74% 0.00% [.] std::__detail::_Adaptor<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul>, double>::operator() (inlined) random.h:185
44.68% 0.00% [.] std::_Norm_helper<true>::_S_do_it<double> (inlined) complex:654
44.68% 0.00% [.] std::__complex_abs (inlined) complex:589
44.68% 0.00% [.] std::abs<double> (inlined) complex:597
44.68% 0.00% [.] std::norm<double> (inlined) complex:664
39.80% 13.59% [.] std::generate_canonical<double, 53ul, std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul> > random.tcc:3330
36.01% 0.00% [.] hypot hypot+18446603487892193300
26.81% 0.00% [.] std::__detail::__mod<unsigned long, 2147483647ul, 16807ul, 0ul> (inlined) random.h:151
26.81% 0.00% [.] std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul>::operator() (inlined) random.h:332
25.75% 0.00% [.] std::__detail::_Mod<unsigned long, 2147483647ul, 16807ul, 0ul, true, true>::__calc (inlined) random.h:143
25.19% 25.19% [.] std::generate_canonical<double, 53ul, std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul> > random.h:143
4.13% 4.13% [.] __hypot_finite __hypot_finite+163
4.13% 0.00% [.] __hypot_finite __hypot_finite+18446603487892193443
...
~~~~~

Compared to the old behavior, this reduces duplication in the output.
Before we used to print the symbol name in the srcline column even
when the sym column was explicitly requested. I.e. the output was:

~~~~~
perf report --inline -s sym,srcline -g none --stdio
...
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 1K of event 'cycles:uppp'
# Event count (approx.): 1381229476
#
# Children Self Symbol Source:Line
# ........ ........ ................................................................................................................................... ..................................................................................................................................
#
94.23% 0.00% [.] __libc_start_main __libc_start_main+18446603487898210537
94.23% 0.00% [.] _start _start+41
44.58% 0.00% [.] main main+100
44.58% 0.00% [.] std::_Norm_helper<true>::_S_do_it<double> (inlined) std::_Norm_helper<true>::_S_do_it<double>+100
44.58% 0.00% [.] std::__complex_abs (inlined) std::__complex_abs+100
44.58% 0.00% [.] std::abs<double> (inlined) std::abs<double>+100
44.58% 0.00% [.] std::norm<double> (inlined) std::norm<double>+100
36.01% 0.00% [.] hypot hypot+18446603487892193300
25.81% 0.00% [.] main main+41
25.81% 0.00% [.] std::__detail::_Adaptor<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul>, double>::operator() (inlined) std::__detail::_Adaptor<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul>, double>::operator()+41
25.81% 0.00% [.] std::uniform_real_distribution<double>::operator()<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul> > (inlined) std::uniform_real_distribution<double>::operator()<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul> >+41
25.69% 25.69% [.] std::generate_canonical<double, 53ul, std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul> > random.h:143
18.39% 0.00% [.] main main+57
18.39% 0.00% [.] std::__detail::_Adaptor<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul>, double>::operator() (inlined) std::__detail::_Adaptor<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul>, double>::operator()+57
18.39% 0.00% [.] std::uniform_real_distribution<double>::operator()<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul> > (inlined) std::uniform_real_distribution<double>::operator()<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul> >+57
13.80% 13.80% [.] std::generate_canonical<double, 53ul, std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul> > random.tcc:3330
4.13% 4.13% [.] __hypot_finite __hypot_finite+163
4.13% 0.00% [.] __hypot_finite __hypot_finite+18446603487892193443
...
~~~~~

Signed-off-by: Milian Wolff <milian.wolff@kdab.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20171019113836.5548-5-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/callchain.c | 1 +
tools/perf/util/event.c | 1 +
tools/perf/util/hist.c | 2 ++
tools/perf/util/symbol.h | 1 +
4 files changed, 5 insertions(+)

diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index 19bfcadcf891..3a3916934a92 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -1090,6 +1090,7 @@ int fill_callchain_info(struct addr_location *al, struct callchain_cursor_node *
{
al->map = node->map;
al->sym = node->sym;
+ al->srcline = node->srcline;
if (node->map)
al->addr = node->map->map_ip(node->map, node->ip);
else
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 47eff4767edb..3c411e7e36aa 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -1604,6 +1604,7 @@ int machine__resolve(struct machine *machine, struct addr_location *al,
al->sym = NULL;
al->cpu = sample->cpu;
al->socket = -1;
+ al->srcline = NULL;

if (al->cpu >= 0) {
struct perf_env *env = machine->env;
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index b0fa9c217e1c..25d143053ab5 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -596,6 +596,7 @@ __hists__add_entry(struct hists *hists,
.map = al->map,
.sym = al->sym,
},
+ .srcline = al->srcline ? strdup(al->srcline) : NULL,
.socket = al->socket,
.cpu = al->cpu,
.cpumode = al->cpumode,
@@ -950,6 +951,7 @@ iter_add_next_cumulative_entry(struct hist_entry_iter *iter,
.map = al->map,
.sym = al->sym,
},
+ .srcline = al->srcline ? strdup(al->srcline) : NULL,
.parent = iter->parent,
.raw_data = sample->raw_data,
.raw_size = sample->raw_size,
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index d880a059babb..d548ea5cb418 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -209,6 +209,7 @@ struct addr_location {
struct thread *thread;
struct map *map;
struct symbol *sym;
+ const char *srcline;
u64 addr;
char level;
u8 filtered;
--
2.13.6