ath_rate/sample/sample.c

84  * in "Bit-rate Selection in Wireless Networks"
87  * SampleRate chooses the bit-rate it predicts will provide the most
89  * transmission time for each bit-rate.  SampleRate periodically sends
91  * another bit-rate will provide better performance. SampleRate
92  * switches to another bit-rate when its estimated per-packet
93  * transmission time becomes smaller than the current bit-rate's.
96  * currently being used.  SampleRate also stops probing at a bit-rate
174 		if ((mask & 1) == 0)		/* not a supported rate */
177 		/* Don't pick a non-HT rate for a HT node */
197 		/* don't use a bit-rate that has been failing */
202 		 * For HT, Don't use a bit rate that is much more
243  * Pick a good "random" bit-rate to sample other than the current one.
258 		/* no successes yet, send at the lowest bit-rate */
265 	rix = sn->last_sample_rix[size_bin]+1;	/* next sample rate */
266 	mask = sn->ratemask &~ ((uint64_t) 1<<current_rix);/* don't sample current rate */
268 		if ((mask & ((uint64_t) 1<<rix)) == 0) {	/* not a supported rate */
284 		 * selected rate is non-MCS, this won't work.
291 		/* if the node is HT and the rate isn't HT, don't bother sample */
299 		/* this bit-rate is always worse than the current one */
375 		 * A fixed rate is to be used; ucastrate is the IEEE code
376 		 * for this rate (sans basic bit).  Check this against the
377 		 * negotiated rate set for the node.  Note the fixed rate
379 		 * setup the static rate index if the lookup is successful.
388  * Pick a non-HT rate to begin using.
412 		 * Pick the highest rate <= 36 Mbps
427  * Pick a HT rate to begin using.
449 		/* Keep a copy of the last seen HT rate index */
458 		 * Pick a medium-speed rate regardless of stream count
530 		     &an->an_node, "att %d sample_tt %d size %u sample rate %d %s current rate %d %s",
556 			/* let the bit-rate switch quickly during the first few packets */
570 			/* the current bit-rate is twice as slow as the best one */
581 			 * If the node is HT, upgrade it if the MCS rate is
583 			 * the current rate. It can fail a little.
609 "%s: size %d switch rate %d (%d/%d) -> %d (%d/%d) after %d packets mrr %d",
788 			 * bit-rate then a larger one will also.
806 	/* Calculate percentage based on current rate */
828 "%s: size %d %s sample rate %d %s tries (%d/%d) tt %d avg_tt (%d/%d) nfrm %d nbad %d",
878 		    "%s: size %d %s rate/try %d/%d no rates yet",
898 		 * Only one rate was used; optimize work.
901 		     &an->an_node, "%s: size %d (%d bytes) %s rate/short/long %d %s/%d/%d nframes/nbad [%d/%d]",
926 "%s: size %d (%d bytes) finaltsidx %d short %d long %d %s rate/try [%d %s/%d %d %s/%d %d %s/%d %d %s/%d] nframes/nbad [%d/%d]",
1042 	KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
1059 	 * to be ignored for doing rate control.
1086 		    ("rate %u has rix %d", RATE(x), rix));
1093 		ieee80211_note(ni->ni_vap, "[%6D] %s: size 1600 rate/tt",
1112 		/* XXX start with first valid rate */
1117 		 * indexed by the rate code index.
1120 			if ((mask & 1) == 0)		/* not a valid rate */
1147 	/* set the visible bit-rate */
1162  * The main difference here is that we convert the rate indexes
1204 	 * Populate the rate table mapping TLV.
1215 	 * First TLV - rate code mapping
1317 	int rate, error;
1319 	rate = ssc->smoothing_rate;
1320 	error = sysctl_handle_int(oidp, &rate, 0, req);
1323 	if (!(0 <= rate && rate < 100))
1325 	ssc->smoothing_rate = rate;
1326 	ssc->smoothing_minpackets = 100 / (100 - rate);
1334 	int rate, error;
1336 	rate = ssc->sample_rate;
1337 	error = sysctl_handle_int(oidp, &rate, 0, req);
1340 	if (!(2 <= rate && rate <= 100))
1342 	ssc->sample_rate = rate;
1355 	    "sample: smoothing rate for avg tx time (%%)");
1378 	ssc->max_successive_failures = 3;	/* threshold for rate sampling*/