[dpdk-dev] [PATCH v14 5/6] lib: added new library for latency stats

Thomas Monjalon thomas.monjalon at 6wind.com
Wed Apr 5 16:24:57 CEST 2017


2017-03-30 22:01, Remy Horton:
> +               /*
> +                * The jitter is calculated as statistical mean of interpacket
> +                * delay variation. The "jitter estimate" is computed by taking
> +                * the absolute values of the ipdv sequence and applying an
> +                * exponential filter with parameter 1/16 to generate the
> +                * estimate. i.e J=J+(|D(i-1,i)|-J)/16. Where J is jitter,
> +                * D(i-1,i) is difference in latency of two consecutive packets
> +                * i-1 and i.
> +                * Reference: Calculated as per RFC 5481, sec 4.1,
> +                * RFC 3393 sec 4.5, RFC 1889 sec.
> +                */
> +               glob_stats->jitter +=  (abs(prev_latency - latency[i])
> +                                       - glob_stats->jitter)/16;
> 

lib/librte_latencystats/rte_latencystats.c:204:27: fatal error:
using integer absolute value function 'abs'
when argument is of floating point type [-Wabsolute-value]
                glob_stats->jitter +=  (abs(prev_latency - latency[i])
                                        ^
note: use function 'fabsf' instead

I am a bit sad to see such error at v14.
Do you want I fix it for you?


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