[tip:perf/core] perf report: Show call graph from reference events
From: tip-bot for Kan Liang
Date: Thu Aug 13 2015 - 04:07:54 EST
Commit-ID: 9e207ddfa20781e56465ce9a537f0a377c9d34fb
Gitweb: http://git.kernel.org/tip/9e207ddfa20781e56465ce9a537f0a377c9d34fb
Author: Kan Liang <kan.liang@xxxxxxxxx>
AuthorDate: Tue, 11 Aug 2015 06:30:49 -0400
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 12 Aug 2015 13:20:28 -0300
perf report: Show call graph from reference events
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@xxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1439289050-40510-3-git-send-email-kan.liang@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Documentation/perf-report.txt | 11 +++++++++++
tools/perf/builtin-report.c | 7 +++++++
tools/perf/ui/browsers/hists.c | 9 +++++++--
tools/perf/util/hist.c | 7 ++++++-
tools/perf/util/symbol.h | 3 ++-
5 files changed, 33 insertions(+), 4 deletions(-)
diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index 7b07d19..a18ba75 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -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
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index f301e86..62b285e 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -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 = {
diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index f296b73..10c7ec0 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -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)
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 1cd785b..08b6cd9 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -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);
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index b98ce51..a4cde92 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -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,
--
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