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Commit d854861c authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 4eed11d5

tools/perf/builtin-test.c

+83 −0
Original line number Diff line number Diff line
@@ -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);
@@ -242,6 +321,10 @@ static struct test { 
		.desc = "vmlinux symtab matches kallsyms",

		.func = test__vmlinux_matches_kallsyms,

	},

	{

		.desc = "detect open syscall event",

		.func = test__open_syscall_event,

	},

	{

		.func = NULL,

	},