[tip:perf/core] perf evlist: Add can_select_event() method

From: tip-bot for Adrian Hunter
Date: Mon Dec 16 2013 - 10:27:39 EST


Commit-ID: c09ec622629eeb4b7877646a42852e7156363425
Gitweb: http://git.kernel.org/tip/c09ec622629eeb4b7877646a42852e7156363425
Author: Adrian Hunter <adrian.hunter@xxxxxxxxx>
AuthorDate: Wed, 11 Dec 2013 14:36:29 +0200
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 13 Dec 2013 10:30:20 -0300

perf evlist: Add can_select_event() method

Add a function to determine whether an event can be selected.

This function is needed to allow a tool to automatically select
additional events, but only if they are available.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1386765443-26966-18-git-send-email-alexander.shishkin@xxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/evlist.h | 2 ++
tools/perf/util/record.c | 37 +++++++++++++++++++++++++++++++++++++
2 files changed, 39 insertions(+)

diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 649d6ea..8a04aae 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -193,4 +193,6 @@ static inline void perf_mmap__write_tail(struct perf_mmap *md,
pc->data_tail = tail;
}

+bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str);
+
#endif /* __PERF_EVLIST_H */
diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c
index c8845b1..e510453 100644
--- a/tools/perf/util/record.c
+++ b/tools/perf/util/record.c
@@ -177,3 +177,40 @@ int perf_record_opts__config(struct perf_record_opts *opts)
{
return perf_record_opts__config_freq(opts);
}
+
+bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str)
+{
+ struct perf_evlist *temp_evlist;
+ struct perf_evsel *evsel;
+ int err, fd, cpu;
+ bool ret = false;
+
+ temp_evlist = perf_evlist__new();
+ if (!temp_evlist)
+ return false;
+
+ err = parse_events(temp_evlist, str);
+ if (err)
+ goto out_delete;
+
+ evsel = perf_evlist__last(temp_evlist);
+
+ if (!evlist || cpu_map__empty(evlist->cpus)) {
+ struct cpu_map *cpus = cpu_map__new(NULL);
+
+ cpu = cpus ? cpus->map[0] : 0;
+ cpu_map__delete(cpus);
+ } else {
+ cpu = evlist->cpus->map[0];
+ }
+
+ fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
+ if (fd >= 0) {
+ close(fd);
+ ret = true;
+ }
+
+out_delete:
+ perf_evlist__delete(temp_evlist);
+ return ret;
+}
--
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