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perf report: Show call graph from reference events

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Introduce --show-ref-call-graph for perf report to print reference
callgraph for no callgraph event.

Here is an example.

 perf report --show-ref-call-graph --stdio

 # To display the perf.data header info, please use
 --header/--header-only options.
 #
 #
 # Total Lost Samples: 0
 #
 # Samples: 5  of event 'cpu/cpu-cycles,call-graph=fp/'
 # Event count (approx.): 144985
 #
 # Children      Self  Command  Shared Object     Symbol
 # ........  ........  .......  ................  ........................................
 #
    72.30%     0.00%  sleep    [kernel.vmlinux]  [k] entry_SYSCALL_64_fastpath
              |
              ---entry_SYSCALL_64_fastpath
                 |
                 |--22.62%-- __GI___libc_nanosleep
                  --77.38%-- [...]

......

 # Samples: 6  of event 'cpu/instructions,call-graph=no/', show reference callgraph
 # Event count (approx.): 172780
 #
 # Children      Self  Command  Shared Object     Symbol
 # ........  ........  .......  ................  ........................................
 #
    73.16%     0.00%  sleep    [kernel.vmlinux]  [k] entry_SYSCALL_64_fastpath
              |
              ---entry_SYSCALL_64_fastpath
                 |
                 |--31.44%-- __GI___libc_nanosleep
                  --68.56%-- [...]

Signed-off-by: Kan Liang <kan.liang@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1439289050-40510-3-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Kan Liang 2015-08-11 06:30:49 -04:00 • committed by Arnaldo Carvalho de Melo
parent f9db0d0f1b
commit 9e207ddfa2
5 changed files with 33 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

11
tools/perf/Documentation/perf-report.txt
View file

@ -359,6 +359,17 @@ OPTIONS
--full-source-path::
Show the full path for source files for srcline output.
--show-ref-call-graph::
When multiple events are sampled, it may not be needed to collect
callgraphs for all of them. The sample sites are usually nearby,
and it's enough to collect the callgraphs on a reference event.
So user can use "call-graph=no" event modifier to disable callgraph
for other events to reduce the overhead.
However, perf report cannot show callgraphs for the event which
disable the callgraph.
This option extends the perf report to show reference callgraphs,
which collected by reference event, in no callgraph event.
include::callchain-overhead-calculation.txt[]
SEE ALSO

7
tools/perf/builtin-report.c
View file

@ -316,6 +316,11 @@ static size_t hists__fprintf_nr_sample_events(struct hists *hists, struct report
if (evname != NULL)
ret += fprintf(fp, " of event '%s'", evname);
if (symbol_conf.show_ref_callgraph &&
strstr(evname, "call-graph=no")) {
ret += fprintf(fp, ", show reference callgraph");
}
if (rep->mem_mode) {
ret += fprintf(fp, "\n# Total weight : %" PRIu64, nr_events);
ret += fprintf(fp, "\n# Sort order : %s", sort_order ? : default_mem_sort_order);
@ -740,6 +745,8 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
itrace_parse_synth_opts),
OPT_BOOLEAN(0, "full-source-path", &srcline_full_filename,
"Show full source file name path for source lines"),
OPT_BOOLEAN(0, "show-ref-call-graph", &symbol_conf.show_ref_callgraph,
"Show callgraph from reference event"),
OPT_END()
};
struct perf_data_file file = {

9
tools/perf/ui/browsers/hists.c
View file

@ -1267,6 +1267,8 @@ static int hists__browser_title(struct hists *hists,
const char *ev_name = perf_evsel__name(evsel);
char buf[512];
size_t buflen = sizeof(buf);
char ref[30] = " show reference callgraph, ";
bool enable_ref = false;
if (symbol_conf.filter_relative) {
nr_samples = hists->stats.nr_non_filtered_samples;
@ -1292,10 +1294,13 @@ static int hists__browser_title(struct hists *hists,
}
}
if (symbol_conf.show_ref_callgraph &&
strstr(ev_name, "call-graph=no"))
enable_ref = true;
nr_samples = convert_unit(nr_samples, &unit);
printed = scnprintf(bf, size,
"Samples: %lu%c of event '%s', Event count (approx.): %" PRIu64,
nr_samples, unit, ev_name, nr_events);
"Samples: %lu%c of event '%s',%sEvent count (approx.): %" PRIu64,
nr_samples, unit, ev_name, enable_ref ? ref : " ", nr_events);
if (hists->uid_filter_str)

7
tools/perf/util/hist.c
View file

@ -1141,7 +1141,12 @@ void hists__output_resort(struct hists *hists, struct ui_progress *prog)
struct hist_entry *n;
u64 min_callchain_hits;
struct perf_evsel *evsel = hists_to_evsel(hists);
bool use_callchain = evsel ? (evsel->attr.sample_type & PERF_SAMPLE_CALLCHAIN) : symbol_conf.use_callchain;
bool use_callchain;
if (evsel && !symbol_conf.show_ref_callgraph)
use_callchain = evsel->attr.sample_type & PERF_SAMPLE_CALLCHAIN;
else
use_callchain = symbol_conf.use_callchain;
min_callchain_hits = hists->stats.total_period * (callchain_param.min_percent / 100);

3
tools/perf/util/symbol.h
View file

@ -106,7 +106,8 @@ struct symbol_conf {
filter_relative,
show_hist_headers,
branch_callstack,
has_filter;
has_filter,
show_ref_callgraph;
const char *vmlinux_name,
*kallsyms_name,
*source_prefix,