Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 28/50] mac80211: minstrel: Change expected throughput unit back to Kbps | Date | Mon, 14 Mar 2016 10:50:46 -0700 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Sven Eckelmann <sven.eckelmann@open-mesh.com>
commit 212c5a5e6ba61678be6b5fee576e38bccb50b613 upstream.
The change from cur_tp to the function minstrel_get_tp_avg/minstrel_ht_get_tp_avg changed the unit used for the current throughput. For example in minstrel_ht the correct conversion between them would be:
mrs->cur_tp / 10 == minstrel_ht_get_tp_avg(..).
This factor 10 must also be included in the calculation of minstrel_get_expected_throughput and minstrel_ht_get_expected_throughput to return values with the unit [Kbps] instead of [10Kbps]. Otherwise routing algorithms like B.A.T.M.A.N. V will make incorrect decision based on these values. Its kernel based implementation expects expected_throughput always to have the unit [Kbps] and not sometimes [10Kbps] and sometimes [Kbps].
The same requirement has iw or olsrdv2's nl80211 based statistics module which retrieve the same data via NL80211_STA_INFO_TX_BITRATE.
Fixes: 6a27b2c40b48 ("mac80211: restructure per-rate throughput calculation into function") Signed-off-by: Sven Eckelmann <sven@open-mesh.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- net/mac80211/rc80211_minstrel.c | 2 +- net/mac80211/rc80211_minstrel_ht.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-)
--- a/net/mac80211/rc80211_minstrel.c +++ b/net/mac80211/rc80211_minstrel.c @@ -711,7 +711,7 @@ static u32 minstrel_get_expected_through * computing cur_tp */ tmp_mrs = &mi->r[idx].stats; - tmp_cur_tp = minstrel_get_tp_avg(&mi->r[idx], tmp_mrs->prob_ewma); + tmp_cur_tp = minstrel_get_tp_avg(&mi->r[idx], tmp_mrs->prob_ewma) * 10; tmp_cur_tp = tmp_cur_tp * 1200 * 8 / 1024; return tmp_cur_tp; --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -1334,7 +1334,8 @@ static u32 minstrel_ht_get_expected_thro prob = mi->groups[i].rates[j].prob_ewma; /* convert tp_avg from pkt per second in kbps */ - tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * AVG_PKT_SIZE * 8 / 1024; + tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10; + tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024; return tp_avg; }
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