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Date: Wed, 29 Apr 2015 14:26:34 +0300
From: Adrian Hunter <adrian.hunter@intel.com>
Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki,
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To: Jiri Olsa <jolsa@redhat.com>
CC: Arnaldo Carvalho de Melo <acme@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>, linux-kernel@vger.kernel.org,
        David Ahern <dsahern@gmail.com>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Namhyung Kim <namhyung@gmail.com>,
        Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH V3 04/25] perf tools: Add AUX area tracing index
References: <1429903807-20559-1-git-send-email-adrian.hunter@intel.com> <1429903807-20559-5-git-send-email-adrian.hunter@intel.com> <20150428120746.GA22258@krava.redhat.com>
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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.