[v8,3/8] perf tests: Add testcase for auxiliary evlist

Message ID 1466419645-75551-4-git-send-email-wangnan0@huawei.com
State New
Headers show

Commit Message

Wang Nan June 20, 2016, 10:47 a.m.
Improve test backward-ring-buffer, trace both enter and exit event of
prctl() syscall, utilize auxiliary evlist to mmap enter and exit event
into separated mmaps.

Signed-off-by: Wang Nan <wangnan0@huawei.com>

Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: He Kuang <hekuang@huawei.com>
---
 tools/perf/tests/backward-ring-buffer.c | 87 ++++++++++++++++++++++++++-------
 1 file changed, 68 insertions(+), 19 deletions(-)

-- 
1.8.3.4

Comments

Wang Nan June 22, 2016, 4:10 a.m. | #1
On 2016/6/22 5:05, Arnaldo Carvalho de Melo wrote:
> Em Mon, Jun 20, 2016 at 10:47:20AM +0000, Wang Nan escreveu:

>> Improve test backward


[SNIP]

>>

>> diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c

>> index d9ba991..76e34c0 100644

>> --- a/tools/perf/tests/backward-ring-buffer.c

>> +++ b/tools/perf/tests/backward-ring-buffer.c

>> @@ -31,16 +31,19 @@ static int count_samples(struct perf_evlist *evlist, int *sample_count,

>>   	for (i = 0; i < evlist->nr_mmaps; i++) {

>>   		union perf_event *event;

>>   

>> -		perf_evlist__mmap_read_catchup(evlist, i);

>> -		while ((event = perf_evlist__mmap_read_backward(evlist, i)) != NULL) {

>> +		if (evlist->backward)

>> +			perf_evlist__mmap_read_catchup(evlist, i);

> So, shouldn't this be done at perf_evlist__mmap_read_catchup()? I.e. you

> will use this only when you know that one of the evlists count_samples()

> will deal with can be a backwards one...

>

> I.e. do with perf_evlist__mmap_read_catchup the same thing you did in

> perf_evlist__mmap_read, checking there this evlist->backward.


I can make the code clearer, but I don't agree hiding evlist->backward 
checker in
perf_evlist__mmap_read_catchup():

1. If we make perf_evlist__mmap_read_catchup() implicitly ignore 
non-backward evlist,
    then we are creating a new rule for reading from mmaps that, before 
calling
    perf_evlist__mmap_read() we need to call 
perf_evlist__mmap_read_catchup() first.
    Theoretically, existing code should be adjusted to satisify this new 
rule, but
    actually most of catchup does nothing.

    If we don't require existing code be adjusted, then we are still 
required to
    clarify when catchup() is required, so evlist->backward is still 
exposed.

2. I think we don't need to restrict perf_evlist__mmap_read_catchup() 
for backward
    ring buffer. It is a generic operations, can be used for a normal 
evlist to
    consume existing data in ring buffer.


> This can be done on top, so I'll continue tentatively merging this.

>

>> +		while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {

>>   			const u32 type = event->header.type;

>>   

>>   			switch (type) {

>>   			case PERF_RECORD_SAMPLE:

>> -				(*sample_count)++;

>> +				if (sample_count)

>> +					(*sample_count)++;

>>   				break;

>>   			case PERF_RECORD_COMM:

>> -				(*comm_count)++;

>> +				if (comm_count)

>> +					(*comm_count)++;

> You could've avoided all this by passing some dummy integer pointer for

> the enter_sample_count case. Making the patch smaller helps reviewing

> :-)


Will do.

Thank you.

Patch

diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c
index d9ba991..76e34c0 100644
--- a/tools/perf/tests/backward-ring-buffer.c
+++ b/tools/perf/tests/backward-ring-buffer.c
@@ -31,16 +31,19 @@  static int count_samples(struct perf_evlist *evlist, int *sample_count,
 	for (i = 0; i < evlist->nr_mmaps; i++) {
 		union perf_event *event;
 
-		perf_evlist__mmap_read_catchup(evlist, i);
-		while ((event = perf_evlist__mmap_read_backward(evlist, i)) != NULL) {
+		if (evlist->backward)
+			perf_evlist__mmap_read_catchup(evlist, i);
+		while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
 			const u32 type = event->header.type;
 
 			switch (type) {
 			case PERF_RECORD_SAMPLE:
-				(*sample_count)++;
+				if (sample_count)
+					(*sample_count)++;
 				break;
 			case PERF_RECORD_COMM:
-				(*comm_count)++;
+				if (comm_count)
+					(*comm_count)++;
 				break;
 			default:
 				pr_err("Unexpected record of type %d\n", type);
@@ -51,34 +54,53 @@  static int count_samples(struct perf_evlist *evlist, int *sample_count,
 	return TEST_OK;
 }
 
-static int do_test(struct perf_evlist *evlist, int mmap_pages,
-		   int *sample_count, int *comm_count)
+static int do_test(struct perf_evlist *evlist,
+		   struct perf_evlist *aux_evlist,
+		   int mmap_pages,
+		   int *enter_sample_count,
+		   int *exit_sample_count,
+		   int *comm_count)
 {
 	int err;
 	char sbuf[STRERR_BUFSIZE];
 
-	err = perf_evlist__mmap(evlist, mmap_pages, true);
+	err = perf_evlist__mmap(evlist, mmap_pages, false);
 	if (err < 0) {
 		pr_debug("perf_evlist__mmap: %s\n",
 			 strerror_r(errno, sbuf, sizeof(sbuf)));
 		return TEST_FAIL;
 	}
 
+	err = perf_evlist__mmap(aux_evlist, mmap_pages, true);
+	if (err < 0) {
+		pr_debug("perf_evlist__mmap for aux_evlist: %s\n",
+			 strerror_r(errno, sbuf, sizeof(sbuf)));
+		return TEST_FAIL;
+	}
+
 	perf_evlist__enable(evlist);
 	testcase();
 	perf_evlist__disable(evlist);
 
-	err = count_samples(evlist, sample_count, comm_count);
+	err = count_samples(aux_evlist, exit_sample_count, comm_count);
+	if (err)
+		goto errout;
+	err = count_samples(evlist, enter_sample_count, NULL);
+	if (err)
+		goto errout;
+errout:
 	perf_evlist__munmap(evlist);
+	perf_evlist__munmap(aux_evlist);
 	return err;
 }
 
 
 int test__backward_ring_buffer(int subtest __maybe_unused)
 {
-	int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0;
+	int ret = TEST_SKIP, err;
+	int enter_sample_count = 0, exit_sample_count = 0, comm_count = 0;
 	char pid[16], sbuf[STRERR_BUFSIZE];
-	struct perf_evlist *evlist;
+	struct perf_evlist *evlist, *aux_evlist = NULL;
 	struct perf_evsel *evsel __maybe_unused;
 	struct parse_events_error parse_error;
 	struct record_opts opts = {
@@ -115,11 +137,22 @@  int test__backward_ring_buffer(int subtest __maybe_unused)
 		goto out_delete_evlist;
 	}
 
-	perf_evlist__config(evlist, &opts, NULL);
+	/*
+	 * Set backward bit, ring buffer should be writing from end. Record
+	 * it in aux evlist
+	 */
+	perf_evlist__last(evlist)->overwrite = true;
+	perf_evlist__last(evlist)->attr.write_backward = 1;
 
-	/* Set backward bit, ring buffer should be writing from end */
-	evlist__for_each(evlist, evsel)
-		evsel->attr.write_backward = 1;
+	err = parse_events(evlist, "syscalls:sys_exit_prctl", &parse_error);
+	if (err) {
+		pr_debug("Failed to parse tracepoint event, try use root\n");
+		ret = TEST_SKIP;
+		goto out_delete_evlist;
+	}
+	/* Don't set backward bit for exit event. Record it in main evlist */
+
+	perf_evlist__config(evlist, &opts, NULL);
 
 	err = perf_evlist__open(evlist);
 	if (err < 0) {
@@ -128,24 +161,40 @@  int test__backward_ring_buffer(int subtest __maybe_unused)
 		goto out_delete_evlist;
 	}
 
+	aux_evlist = perf_evlist__new_aux(evlist);
+	if (!aux_evlist) {
+		pr_debug("perf_evlist__new_aux failed\n");
+		goto out_delete_evlist;
+	}
+	aux_evlist->backward = true;
+
 	ret = TEST_FAIL;
-	err = do_test(evlist, opts.mmap_pages, &sample_count,
+	err = do_test(evlist, aux_evlist, opts.mmap_pages,
+		      &enter_sample_count, &exit_sample_count,
 		      &comm_count);
 	if (err != TEST_OK)
 		goto out_delete_evlist;
 
-	if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) {
-		pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n",
-		       sample_count, comm_count);
+	if (enter_sample_count != exit_sample_count) {
+		pr_err("Unexpected counter: enter_sample_count=%d, exit_sample_count=%d\n",
+		       enter_sample_count, exit_sample_count);
+		goto out_delete_evlist;
+	}
+
+	if ((exit_sample_count != NR_ITERS) || (comm_count != NR_ITERS)) {
+		pr_err("Unexpected counter: exit_sample_count=%d, comm_count=%d\n",
+		       exit_sample_count, comm_count);
 		goto out_delete_evlist;
 	}
 
-	err = do_test(evlist, 1, &sample_count, &comm_count);
+	err = do_test(evlist, aux_evlist, 1, NULL, NULL, NULL);
 	if (err != TEST_OK)
 		goto out_delete_evlist;
 
 	ret = TEST_OK;
 out_delete_evlist:
+	if (aux_evlist)
+		perf_evlist__delete(aux_evlist);
 	perf_evlist__delete(evlist);
 	return ret;
 }