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

[Adrian Hunter <adrian.hunter@intel.com>]

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@intel.com>
> 
> 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);
> 
>