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Subject: Re: [PATCH v5 3/7] eal: add lcore variable performance test
To: =?UTF-8?Q?Morten_Br=C3=B8rup?= <mb@smartsharesystems.com>,
 =?UTF-8?Q?Mattias_R=C3=B6nnblom?= <mattias.ronnblom@ericsson.com>,
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Cc: Stephen Hemminger <stephen@networkplumber.org>,
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 <20240917143239.724069-1-mattias.ronnblom@ericsson.com>
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On 2024-09-17 17:40, Morten Brørup wrote:
>> +	start = rte_rdtsc();
>> +
>> +	for (i = 0; i < ITERATIONS; i++)
>> +		update_fun(mods[i & num_mods_mask]);
> 
> This indexing adds more instructions to be executed than just the update function.
> The added overhead is the same for all tested access methods, so the absolute difference in latency (i.e. measured in cycles) is still perfectly valid.
> Just mentioning it; no change required.
> 
>> +
>> +	end = rte_rdtsc();
>> +
>> +	latency = (end - start) / ITERATIONS;
> 
> This calculation is integer; add (double) somewhere to make it floating point.
> 

Indeed, it is. Will fix.

>> +
>> +	return latency;
>> +}
>