[tip:perf/core] perf test: Add test for counting open syscalls

tip-bot for Arnaldo Carvalho de Melo
2011-01-04T08:26:47Z

Commit-ID: d854861c4292a4e675a5d3bfd862c5f7421c81e8
Gitweb: http://git.kernel.org/tip/d854861c4292a4e675a5d3bfd862c5f7421c81e8
Author: Arnaldo Carvalho de Melo <acme@redhat.com>
AuthorDate: Tue, 4 Jan 2011 00:16:20 -0200
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 4 Jan 2011 00:32:06 -0200

perf test: Add test for counting open syscalls

To test the use of the perf_evsel class on something other than
the tools from where we refactored code to create it.

It calls open() N times and then checks if the event created to
monitor it returns N events.

[acme@felicio linux]$ perf test
1: vmlinux symtab matches kallsyms: Ok
2: detect open syscall event: Ok
[acme@felicio linux]$

It does.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Han Pingtian <phan@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/builtin-test.c | 83 +++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 83 insertions(+), 0 deletions(-)

diff --git a/tools/perf/builtin-test.c b/tools/perf/builtin-test.c
index e0c3f47..6c99152 100644
--- a/tools/perf/builtin-test.c
+++ b/tools/perf/builtin-test.c
@@ -234,6 +234,85 @@ out:
return err;
}

+#include "util/evsel.h"
+#include <sys/types.h>
+
+static int trace_event__id(const char *event_name)
+{
+ char *filename;
+ int err = -1, fd;
+
+ if (asprintf(&filename,
+ "/sys/kernel/debug/tracing/events/syscalls/%s/id",
+ event_name) < 0)
+ return -1;
+
+ fd = open(filename, O_RDONLY);
+ if (fd >= 0) {
+ char id[16];
+ if (read(fd, id, sizeof(id)) > 0)
+ err = atoi(id);
+ close(fd);
+ }
+
+ free(filename);
+ return err;
+}
+
+static int test__open_syscall_event(void)
+{
+ int err = -1, fd;
+ struct thread_map *threads;
+ struct perf_evsel *evsel;
+ unsigned int nr_open_calls = 111, i;
+ int id = trace_event__id("sys_enter_open");
+
+ if (id < 0) {
+ pr_debug("trace_event__id(\"sys_enter_open\") ");
+ return -1;
+ }
+
+ threads = thread_map__new(-1, getpid());
+ if (threads == NULL) {
+ pr_debug("thread_map__new ");
+ return -1;
+ }
+
+ evsel = perf_evsel__new(PERF_TYPE_TRACEPOINT, id, 0);
+ if (evsel == NULL) {
+ pr_debug("perf_evsel__new ");
+ goto out_thread_map_delete;
+ }
+
+ if (perf_evsel__open_per_thread(evsel, threads) < 0) {
+ pr_debug("perf_evsel__open_per_thread ");
+ goto out_evsel_delete;
+ }
+
+ for (i = 0; i < nr_open_calls; ++i) {
+ fd = open("/etc/passwd", O_RDONLY);
+ close(fd);
+ }
+
+ if (perf_evsel__read_on_cpu(evsel, 0, 0) < 0) {
+ pr_debug("perf_evsel__open_read_on_cpu ");
+ goto out_close_fd;
+ }
+
+ if (evsel->counts->cpu[0].val != nr_open_calls)
+ pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls, got %Ld ",
+ nr_open_calls, evsel->counts->cpu[0].val);
+
+ err = 0;
+out_close_fd:
+ perf_evsel__close_fd(evsel, 1, threads->nr);
+out_evsel_delete:
+ perf_evsel__delete(evsel);
+out_thread_map_delete:
+ thread_map__delete(threads);
+ return err;
+}
+
static struct test {
const char *desc;
int (*func)(void);
@@ -243,6 +322,10 @@ static struct test {
.func = test__vmlinux_matches_kallsyms,
},
{
+ .desc = "detect open syscall event",
+ .func = test__open_syscall_event,
+ },
+ {
.func = NULL,
},
};