9953807c9e
An event group is a critical relationship. There is a -g option that can
display the relationship. But it's hard for a user to know when should
this option be applied.
If there is an event group in the perf record, print a hint to suggest
the user apply the -g to display the group information.
With the patch,
$ perf record -e "{cycles,instructions},instructions" sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.024 MB perf.data (4 samples) ]
$
$ perf evlist
cycles
instructions
instructions
# Tip: use 'perf evlist -g' to show group information
$ perf evlist -g
{cycles,instructions}
instructions
$
Committer testing:
So for a perf.data file _with_ a group:
root@number:~# perf evlist -g
{cpu_core/branch-instructions/pp,cpu_core/branches/}
dummy:u
root@number:~# perf evlist
cpu_core/branch-instructions/pp
cpu_core/branches/
dummy:u
# Tip: use 'perf evlist -g' to show group information
root@number:~#
Then for something _without_ a group, no hint:
root@number:~# perf record ls
<SNIP>
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.035 MB perf.data (7 samples) ]
root@number:~# perf evlist
cpu_atom/cycles/P
cpu_core/cycles/P
dummy:u
root@number:~#
No suggestion, good.
Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Closes: https://lore.kernel.org/lkml/ZttgvduaKsVn1r4p@x1/
Link: https://lore.kernel.org/r/20240908202847.176280-1-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
102 lines
2.8 KiB
C
102 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Builtin evlist command: Show the list of event selectors present
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* in a perf.data file.
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*/
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#include "builtin.h"
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#include <linux/list.h>
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#include "util/evlist.h"
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#include "util/evsel.h"
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#include "util/evsel_fprintf.h"
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#include "util/parse-events.h"
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#include <subcmd/parse-options.h>
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#include "util/session.h"
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#include "util/data.h"
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#include "util/debug.h"
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#include <linux/err.h>
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#include "util/tool.h"
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#include "util/util.h"
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static int process_header_feature(struct perf_session *session __maybe_unused,
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union perf_event *event __maybe_unused)
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{
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session_done = 1;
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return 0;
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}
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static int __cmd_evlist(const char *file_name, struct perf_attr_details *details)
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{
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struct perf_session *session;
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struct evsel *pos;
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struct perf_data data = {
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.path = file_name,
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.mode = PERF_DATA_MODE_READ,
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.force = details->force,
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};
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struct perf_tool tool;
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bool has_tracepoint = false, has_group = false;
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perf_tool__init(&tool, /*ordered_events=*/false);
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/* only needed for pipe mode */
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tool.attr = perf_event__process_attr;
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tool.feature = process_header_feature;
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session = perf_session__new(&data, &tool);
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if (IS_ERR(session))
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return PTR_ERR(session);
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if (data.is_pipe)
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perf_session__process_events(session);
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evlist__for_each_entry(session->evlist, pos) {
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evsel__fprintf(pos, details, stdout);
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if (pos->core.attr.type == PERF_TYPE_TRACEPOINT)
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has_tracepoint = true;
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if (!evsel__is_group_leader(pos))
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has_group = true;
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}
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if (has_tracepoint && !details->trace_fields)
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printf("# Tip: use 'perf evlist --trace-fields' to show fields for tracepoint events\n");
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if (has_group && !details->event_group)
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printf("# Tip: use 'perf evlist -g' to show group information\n");
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perf_session__delete(session);
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return 0;
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}
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int cmd_evlist(int argc, const char **argv)
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{
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struct perf_attr_details details = { .verbose = false, };
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const struct option options[] = {
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OPT_STRING('i', "input", &input_name, "file", "Input file name"),
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OPT_BOOLEAN('F', "freq", &details.freq, "Show the sample frequency"),
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OPT_BOOLEAN('v', "verbose", &details.verbose,
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"Show all event attr details"),
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OPT_BOOLEAN('g', "group", &details.event_group,
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"Show event group information"),
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OPT_BOOLEAN('f', "force", &details.force, "don't complain, do it"),
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OPT_BOOLEAN(0, "trace-fields", &details.trace_fields, "Show tracepoint fields"),
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OPT_END()
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};
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const char * const evlist_usage[] = {
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"perf evlist [<options>]",
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NULL
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};
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argc = parse_options(argc, argv, options, evlist_usage, 0);
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if (argc)
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usage_with_options(evlist_usage, options);
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if (details.event_group && (details.verbose || details.freq)) {
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usage_with_options_msg(evlist_usage, options,
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"--group option is not compatible with other options\n");
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}
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return __cmd_evlist(input_name, &details);
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}
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