rc80211-pid: fix rate adjustment (1d60ab05) · Commits · 戴 / test

net/mac80211/rc80211_pid_algo.c

+43 −49

Original line number	Diff line number	Diff line
		@@ -2,7 +2,7 @@
		* Copyright 2002-2005, Instant802 Networks, Inc.
		* Copyright 2005, Devicescape Software, Inc.
		* Copyright 2007, Mattias Nissler <mattias.nissler@gmx.de>
		* Copyright 2007, Stefano Brivio <stefano.brivio@polimi.it>
		* Copyright 2007-2008, Stefano Brivio <stefano.brivio@polimi.it>
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 as
		@@ -63,72 +63,66 @@
		* RC_PID_ARITH_SHIFT.
		*/


		/* Shift the adjustment so that we won't switch to a lower rate if it exhibited
		* a worse failed frames behaviour and we'll choose the highest rate whose
		* failed frames behaviour is not worse than the one of the original rate
		* target. While at it, check that the adjustment is within the ranges. Then,
		* provide the new rate index. */
		static int rate_control_pid_shift_adjust(struct rc_pid_rateinfo *r,
		int adj, int cur, int l)
		{
		int i, j, k, tmp;

		j = r[cur].rev_index;
		i = j + adj;

		if (i < 0)
		return r[0].index;
		if (i >= l - 1)
		return r[l - 1].index;

		tmp = i;

		if (adj < 0) {
		for (k = j; k >= i; k--)
		if (r[k].diff <= r[j].diff)
		tmp = k;
		} else {
		for (k = i + 1; k + i < l; k++)
		if (r[k].diff <= r[i].diff)
		tmp = k;
		}

		return r[tmp].index;
		}

		/* Adjust the rate while ensuring that we won't switch to a lower rate if it
		* exhibited a worse failed frames behaviour and we'll choose the highest rate
		* whose failed frames behaviour is not worse than the one of the original rate
		* target. While at it, check that the new rate is valid. */
		static void rate_control_pid_adjust_rate(struct ieee80211_local *local,
		struct sta_info *sta, int adj,
		struct rc_pid_rateinfo *rinfo)
		{
		struct ieee80211_sub_if_data *sdata;
		struct ieee80211_hw_mode *mode;
		int newidx;
		int maxrate;
		int back = (adj > 0) ? 1 : -1;
		int cur_sorted, new_sorted, probe, tmp, n_bitrates;
		int cur = sta->txrate;

		sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);

		mode = local->oper_hw_mode;
		maxrate = sdata->bss ? sdata->bss->max_ratectrl_rateidx : -1;
		n_bitrates = mode->num_rates;

		newidx = rate_control_pid_shift_adjust(rinfo, adj, sta->txrate,
		mode->num_rates);
		/* Map passed arguments to sorted values. */
		cur_sorted = rinfo[cur].rev_index;
		new_sorted = cur_sorted + adj;

		while (newidx != sta->txrate) {
		if (rate_supported(sta, mode, newidx) &&
		(maxrate < 0 \|\| newidx <= maxrate)) {
		sta->txrate = newidx;
		break;
		/* Check limits. */
		if (new_sorted < 0)
		new_sorted = rinfo[0].rev_index;
		else if (new_sorted >= n_bitrates)
		new_sorted = rinfo[n_bitrates - 1].rev_index;

		tmp = new_sorted;

		if (adj < 0) {
		/* Ensure that the rate decrease isn't disadvantageous. */
		for (probe = cur_sorted; probe >= new_sorted; probe--)
		if (rinfo[probe].diff <= rinfo[cur_sorted].diff &&
		rate_supported(sta, mode, rinfo[probe].index))
		tmp = probe;
		} else {
		/* Look for rate increase with zero (or below) cost. */
		for (probe = new_sorted + 1; probe < n_bitrates; probe++)
		if (rinfo[probe].diff <= rinfo[new_sorted].diff &&
		rate_supported(sta, mode, rinfo[probe].index))
		tmp = probe;
		}

		newidx += back;
		/* Fit the rate found to the nearest supported rate. */
		do {
		if (rate_supported(sta, mode, rinfo[tmp].index)) {
		sta->txrate = rinfo[tmp].index;
		break;
		}
		if (adj < 0)
		tmp--;
		else
		tmp++;
		} while (tmp < n_bitrates && tmp >= 0);

		#ifdef CONFIG_MAC80211_DEBUGFS
		rate_control_pid_event_rate_change(
		&((struct rc_pid_sta_info *)sta->rate_ctrl_priv)->events,
		newidx, mode->rates[newidx].rate);
		cur, mode->rates[cur].rate);
		#endif
		}

Admin message