d/numam-dpdk
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

bitrate: fix integer roundoff

Browse Source 
In the absence of traffic, it is possible for the bitrate moving average
to get stuck at a non-zero value, due to the calculated delta being less
than what an integer can represent.

Fixes: 2ad7ba9a65 ("bitrate: add bitrate statistics library")

Signed-off-by: Remy Horton <remy.horton@intel.com>
This commit is contained in:
Remy Horton 2017-04-19 14:26:48 +01:00 committed by Thomas Monjalon
parent 917f49cfd0
commit 0caf728114
1 changed files with 7 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
lib/librte_bitratestats/rte_bitrate.c
View File

@ -118,6 +118,11 @@ rte_stats_bitrate_calc(struct rte_stats_bitrates *bitrate_data,
else
delta = (delta * alpha_percent - 50) / 100;
port_data->ewma_ibits += delta;
/* Integer roundoff prevents EWMA between 0 and (100/alpha_percent)
* ever reaching zero in no-traffic conditions
*/
if (cnt_bits == 0 && delta == 0)
port_data->ewma_ibits = 0;
port_data->mean_ibits = cnt_bits;
/* Outgoing bitrate (also EWMA) */
@ -132,6 +137,8 @@ rte_stats_bitrate_calc(struct rte_stats_bitrates *bitrate_data,
else
delta = (delta * alpha_percent - 50) / 100;
port_data->ewma_obits += delta;
if (cnt_bits == 0 && delta == 0)
port_data->ewma_obits = 0;
port_data->mean_obits = cnt_bits;
values[0] = port_data->ewma_ibits;