From 9e207ddfa20781e56465ce9a537f0a377c9d34fb Mon Sep 17 00:00:00 2001 From: Kan Liang Date: Tue, 11 Aug 2015 06:30:49 -0400 Subject: [PATCH] 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 Tested-by: Arnaldo Carvalho de Melo Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Link: http://lkml.kernel.org/r/1439289050-40510-3-git-send-email-kan.liang@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- 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 7b07d19e2d54..a18ba757a0ed 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 f301e865001f..62b285e32aa5 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 f296b7348449..10c7ec041039 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 1cd785b5b56e..08b6cd945f1e 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 b98ce51af142..a4cde92afbad 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,