Re: [PATCH V3 04/25] perf tools: Add AUX area tracing index

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

On 28/04/15 15:07, Jiri Olsa wrote:
> On Fri, Apr 24, 2015 at 10:29:46PM +0300, Adrian Hunter wrote:
> 
> SNIP
> 
>> +
>> +int auxtrace_index__process(int fd, u64 size, struct perf_session *session,
>> +			    bool needs_swap)
>> +{
>> +	struct list_head *head = &session->auxtrace_index;
>> +	u64 nr;
>> +
>> +	if (readn(fd, &nr, sizeof(u64)) != sizeof(u64))
>> +		return -1;
>> +
>> +	if (needs_swap)
>> +		nr = bswap_64(nr);
>> +
>> +	if (sizeof(u64) + nr * sizeof(struct auxtrace_index_entry) != size)
>> +		return -1;
> 
> so the total nr is only used to double check the data size is correct,
> it could be omited and you could use just the size of the section..
> also the auxtrace_index__write would be shorter of one loop
> 
> but no big deal.. just asking ;-)

I would like to have it as a check that the file structure is the way it is
meant to be.

Also I will change it to " > size" so that more stuff can be added to the
section in the future.