Re: [PATCH V5 12/12] perf tools: add a sample parsing test

From: Adrian Hunter
Date: Wed Jul 17 2013 - 06:55:35 EST


On 16/07/13 15:48, Jiri Olsa wrote:
> On Thu, Jul 11, 2013 at 04:12:21PM +0300, Adrian Hunter wrote:
>> Add a test that checks that sample parsing is correctly
>> implemented.
>
> nice!!! :)
>
>>
>> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
>
> SNIP
>
>> +static int do_test(u64 sample_type, u64 sample_regs_user)
>> +{
>> + struct perf_evsel evsel = {
>> + .needs_swap = false,
>> + .attr = {
>> + .sample_type = sample_type,
>> + .sample_regs_user = sample_regs_user,
>> + },
>> + };
>> + union perf_event event = {
>> + .header = {
>> + .type = PERF_RECORD_SAMPLE,
>> + .size = sizeof(union perf_event),
>> + },
>> + };
>
> maybe I'm missing something but how does event.sample.array get
> allocated? It's used in perf_event__synthesize_sample func.

'union perf_event' is very big because of 'struct mmap_event' which contains
'char filename[PATH_MAX]' and PATH_MAX is 4096.

>
> do we need to use something like in the patch below..

Might as well calculate it correctly.

>
> thanks,
> jirka
>
> ---
> diff --git a/tools/perf/tests/sample-parsing.c b/tools/perf/tests/sample-parsing.c
> index c6e6813..dcbd40d 100644
> --- a/tools/perf/tests/sample-parsing.c
> +++ b/tools/perf/tests/sample-parsing.c
> @@ -111,12 +111,8 @@ static int do_test(u64 sample_type, u64 sample_regs_user)
> .sample_regs_user = sample_regs_user,
> },
> };
> - union perf_event event = {
> - .header = {
> - .type = PERF_RECORD_SAMPLE,
> - .size = sizeof(union perf_event),
> - },
> - };
> + u64 buf[100];
> + union perf_event *event = (union perf_event *) buf;
> union {
> struct ip_callchain callchain;
> u64 data[64];
> @@ -162,10 +158,15 @@ static int do_test(u64 sample_type, u64 sample_regs_user)
> size_t i;
> int err;
>
> + event->sample.header = (struct perf_event_header) {
> + .type = PERF_RECORD_SAMPLE,
> + .size = sizeof(union perf_event),
> + };
> +
> for (i = 0; i < sizeof(user_regs); i++)
> *(u8 *)user_regs = i;
>
> - err = perf_event__synthesize_sample(&event, sample_type,
> + err = perf_event__synthesize_sample(event, sample_type,
> sample_regs_user, &sample, false);
> if (err) {
> pr_debug("%s failed for sample_type %#"PRIx64", error %d\n",
> @@ -175,7 +176,7 @@ static int do_test(u64 sample_type, u64 sample_regs_user)
>
> evsel.sample_size = __perf_evsel__sample_size(sample_type);
>
> - err = perf_evsel__parse_sample(&evsel, &event, &sample_out);
> + err = perf_evsel__parse_sample(&evsel, event, &sample_out);
> if (err) {
> pr_debug("%s failed for sample_type %#"PRIx64", error %d\n",
> "perf_evsel__parse_sample", sample_type, err);
>
>

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