Changeset 3361

Timestamp:

02/21/08 23:04:34 (4 years ago)

Author:

benoit

Message:

Reformatting.
Fixed a bug where the percentage of look around packets was not correct

Files:

• madwifi/branches/madwifi-dfs/ath_rate/minstrel/minstrel.c (modified) (13 diffs)
• madwifi/branches/madwifi-dfs/ath_rate/minstrel/minstrel.txt (modified) (13 diffs)

madwifi/branches/madwifi-dfs/ath_rate/minstrel/minstrel.c

@@ -125 +125 @@
-#define DPRINTF(sc, _fmt, ...) do {             \
-                if (sc->sc_debug & ATH_DEBUG_RATE)      \
-_fmt, __VA_ARGS__);             
+"%s: " _fmt, SC_DEV_NAME(sc), __VA_ARGS__); 
-} while (0)
-#else
@@ -141 +141 @@
-#define ENABLE_MRR 1
-
-
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+
-static int ath_lookaround_rate = 10;
-static int ath_ewma_level      = 75;
@@ -335 +337 @@
-                        sn->random_n = (sn->a * sn->random_n) + sn->b;
-                        offset = sn->random_n & 0xf;
-
+
+
-                                sn->sample_count++;
-                                sn->is_sampling = 1;
@@ -544 +547 @@
-
-static void
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-                        }
-                }
+        }
+        
+        for (column_index = 0; column_index < MINSTREL_COLUMNS; column_index++) {
+                for (i = 0; i < num_sample_rates && i < IEEE80211_RATE_MAXSIZE; i++) {
+                        DPRINTF(sc, "rs_sampleTable[%2u][%2u] = %2u\n",
+                                i, column_index, sn->rs_sampleTable[i][column_index]);
+                }
+        }
+}
+
+/* Initialize the tables for a node. */
+static void
+ath_rate_ctl_reset(struct ath_softc *sc, struct ieee80211_node *ni)
+{
+        struct ath_node *an = ATH_NODE(ni);
+        struct minstrel_node *sn = ATH_NODE_MINSTREL(an);
+        struct ieee80211vap *vap = ni->ni_vap;
+        const HAL_RATE_TABLE *rt = sc->sc_currates;
+        unsigned int x;
+        int retry_index, tx_time;
+        int srate;
+        int ndx = 0;
+
+        sn->num_rates = 0;
+        sn->max_tp_rate = 0;
+        sn->max_tp_rate2 = 0;
+        sn->max_prob_rate = 0;
+        sn->packet_count = 0;
+        sn->sample_count = 0;
+        sn->is_sampling = 0;
+
+        if (rt == NULL) {
+                DPRINTF(sc, "no rates yet! mode %u\n", sc->sc_curmode);
+                return;
+        }
+        sn->static_rate_ndx = -1;
+
+        sn->num_rates = ni->ni_rates.rs_nrates;
+        for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
+                sn->rs_rateattempts     [x] = 0;
+                sn->rs_thisprob         [x] = 0;
+                sn->rs_ratesuccess      [x] = 0;
+                sn->rs_lastrateattempts [x] = 0;
+                sn->rs_lastratesuccess  [x] = 0;
+                sn->rs_probability      [x] = 0;
+                sn->rs_succ_hist        [x] = 0;
+                sn->rs_att_hist         [x] = 0;
+                sn->rs_this_tp          [x] = 0;
+
+                sn->rates[x].rate = ni->ni_rates.rs_rates[x] & IEEE80211_RATE_VAL;
+                sn->rates[x].rix = sc->sc_rixmap[sn->rates[x].rate];
+                if (sn->rates[x].rix == 0xff) {
+                        DPRINTF(sc, "%s: %s ignore bogus rix at %d\n",
+                                dev_info, __func__, x);
+                        continue;
+                }
+                sn->rates[x].rateCode = rt->info[sn->rates[x].rix].rateCode;
+                sn->rates[x].shortPreambleRateCode =
+                        rt->info[sn->rates[x].rix].rateCode |
+                        rt->info[sn->rates[x].rix].shortPreamble;
+        }
+        
+        ath_fill_sample_table(sc, sn);
+        
+        ni->ni_txrate = 0;
+
+        if (sn->num_rates <= 0) {
+                DPRINTF(sc, "%s: %s " MAC_FMT " no rates (fixed %d) \n",
+                        dev_info, __func__, MAC_ADDR(ni->ni_macaddr),
+                        vap->iv_fixed_rate);
+                /* There are no rates yet; we're done */
+                return;
+        }
+
+        if (vap->iv_fixed_rate != IEEE80211_FIXED_RATE_NONE) {
+                srate = sn->num_rates - 1;
+
+                /* A fixed rate is to be used; ic_fixed_rate is an
+                 * index into the supported rate set.  Convert this
+                 * to the index into the negotiated rate set for
+                 * the node.  We know the rate is there because the
+                 * rate set is checked when the station associates. */
+                /* NB: the rate set is assumed sorted */
+                for (; (srate >= 0) && (ni->ni_rates.rs_rates[srate] & IEEE80211_RATE_VAL) != vap->iv_fixed_rate; srate--);
+
+                KASSERT(srate >= 0,
+                        ("fixed rate %d not in rate set", vap->iv_fixed_rate));
+
+                sn->static_rate_ndx = srate;
+                ni->ni_txrate = srate;
+                DPRINTF(sc, "%s: %s " MAC_FMT " fixed rate %d%sMbps\n",
+                        dev_info, __func__, MAC_ADDR(ni->ni_macaddr),
+                        sn->rates[srate].rate / 2,
+                        (sn->rates[srate].rate % 2) ? ".5 " : " ");
+                return;
+        }
+
+        for (x = 0; x < ni->ni_rates.rs_nrates; x++) {
+                if (sn->rates[x].rix == 0xff) {
+                        DPRINTF(sc, "%s: %s ignore bogus rix at %d\n",
+                                dev_info, __func__, x);
+                        continue;
+                }
+
+                sn->rs_rateattempts     [x] = 0;
+                sn->rs_thisprob         [x] = 0;
+                sn->rs_ratesuccess      [x] = 0;
+                sn->rs_probability      [x] = 0;
+                sn->rs_lastrateattempts [x] = 0;
+                sn->rs_lastratesuccess  [x] = 0;
+                sn->rs_succ_hist        [x] = 0;
+                sn->rs_att_hist         [x] = 0;
+                sn->perfect_tx_time     [x] =
+                        calc_usecs_unicast_packet(sc, 1200,
+                                                  sn->rates[x].rix,
+                                                  0, 0);
+                sn->retry_count         [x] = 1;
+                sn->retry_adjusted_count[x] = 1;
+
+                for (retry_index = 2; retry_index < ATH_TXMAXTRY; retry_index++) {
+                        tx_time = calc_usecs_unicast_packet(sc, 1200, sn->rates[x].rix, 0, retry_index);
+                        if (tx_time > ath_segment_size)
+                                break;
+                        sn->retry_count[x] = retry_index;
+                        sn->retry_adjusted_count[x] = retry_index;
+                }
+        }
-
-#if 0
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+
-#endif
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-}
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@@ -749 +748 @@
-ath_timer_function(unsigned long data)
-{
-       
-       
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-}
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@@ -793 +792 @@
-ath_rate_statistics(void *arg, struct ieee80211_node *ni)
-{
-       
-       
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-}
-
@@ -879 +878 @@
-ath_rate_attach(struct ath_softc *sc)
-{
-       
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-           
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-        osc->sc          = sc;
-       
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-}
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@@ -919 +918 @@
-ath_proc_read_nodes(struct ieee80211vap *vap, char *buf, int space)
-{
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@@ -986 +985 @@
-ath_proc_ratesample_open(struct inode *inode, struct file *file)
-{
-       
-       
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-                         
-           
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-static struct file_operations ath_proc_ratesample_ops = {
-       
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-};
-
@@ -1029 +1028 @@
-ath_rate_dynamic_proc_register(struct ieee80211vap *vap)
-{
-       
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-}
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@@ -1036 +1035 @@
-
-static struct ieee80211_rate_ops ath_rate_ops = {
-       
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@@ -1060 +1059 @@
-static int __init ath_rate_minstrel_init(void)
-{
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-}
-module_init(ath_rate_minstrel_init);
@@ -1074 +1073 @@
-static void __exit ath_rate_minstrel_exit(void)
-{
-       
-       
+
+
-}
-module_exit(ath_rate_minstrel_exit);

madwifi/branches/madwifi-dfs/ath_rate/minstrel/minstrel.txt

@@ -1 @@
-
-
+
-
-Introduction
-
+
+
-This code is called minstrel, because we have taken a wandering minstrel
-
-
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+
+
+
+
+
+
+
+
-  http://sourceforge.net/mailarchive/forum.php?forum_id=33966&max_rows=25&style=flat&viewmonth=200501&viewday=5
-
-
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-We noted:
-
+
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-    environment.
-
-
-
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-    data rate, and would not move to a higher data rate.
-
-
-rewrite 
+ rewrite
+
-
-Theory of operation
-
-
- 
-
-mega-bits-
-
-
-
- 
+============
+
+
+
+Mega bits 
+-
+ 
+
+
-get the maximum number of data bits through the radio interface. Further, it
-mb/sec
-mb/sec
+ Mbits
+ Mbits
-
-We decided that the module should record the successfulness of all packets
@@ -55 +58 @@
-rates regarded as non optimal.
-
-
-a 
+ a
+
-(described below) are used to process the success history of each rate. On
-completion of the calculation, a decision is made as to the rate which has the
- 
+
-This data is used for populating the retry chain during the next 100 ms.
-
-As stated above, the minstrel algorithm collects statistics from all packet
- 
-
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-ms. Any
-
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+ percentage
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-
-Retry Chain
-
+
+
-The HAL provides a multirate retry chain - which consists of four
-segments. Each segment is an advisement to the HAL to try to send the current
@@ -84 +88 @@
-successfully transmitted, the remainder of the retry chain is
-ignored. Selection of the number of retry attempts was based on the desire to
-
+ 
-ath_segment_size, which has units of microseconds, and specifies the maximum
-duration one segment in the retry chain can last. This module parameter has a
@@ -91 +95 @@
-
-There is some room for movement here - if the traffic is UDP then the limit of
-ms for the retry chain length is "meaningless". 
+ ms for the retry chain length is "meaningless".
-if the packet was not transmitted after some time period, it should
-fail. Further, one does expect UDP packets to fail in transmission. We leave
@@ -116 +120 @@
-After some discussion, we have adjusted the code so that the lowest rate is
-never used for the lookaround packet. Our view is that since this rate is used
-- Alternatively, the link
-
-
-die 
-
-
-
-
-
-probability rates, we 
-
-
-
-ampling the slower rates. Thus, for two nodes adjacent to each other,
-
-
-
-minstrel should immediately sample at 
-
-
-
-rates are 
+Alternatively, the link is
+
+
+
+
+ showed
+
+
+
+
+
+ key
+
+lower rates. Thus, for two nodes adjacent to each other, the throughput
+
+
+
+
+
+ was to
+
+
-
-Try |         Lookaround rate              | Normal rate         
@@ -150 +154 @@
-current best throughput, the randomly selected rate is placed second in the
-chain. If the link is not good, then there will be data collected at the
-mbs,
-
+
+Mbits, 
-transmission. Consequently, if the link is ideal, all packets will be sent at
-mb
+ Mbit
-
-EWMA
-
+============
-
-The EWMA calculation is carried out 10 times a second, and is run for each
-
-
-
-Given 
-
-
+ a
+
+
+
+
+ 
-interval. Old results are the EWMA scaling values from before the just
-
+ 
-
-EWMA scaling is set by the module parameter ath_ewma_level, and defaults to
-
-
-
-
-
+
+
+
-
-The calculation (performed for each rate, at each timer interrupt) of the
-         
+
-
-         Psucces_this_time_interval * (100 - ath_ewma_level) + (Pold * ath_ewma_level)
@@ -193 +195 @@
-inserted), then Pnew is calculated from above with Pold set to 0.
-
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-
-A sudden change in the transmission probabilities will happen when the
@@ -210 +215 @@
-layers.
-
-
-
-Module Parameters
-
+==========================
-The module has three parameters:
-
@@ -226 +229 @@
-
-Test Network
-
-
+
+
+
-atheros cards running in adhoc mode. We used a program that sends a fixed
-number of TCP packets between computers, and reports on the data rate. The
@@ -239 +243 @@
-
-It was from monitoring the results on the third computer that we started to
-
-
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+
+
+
+
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+
-
-We recorded throughputs (with minstrel) that are within 10% of what is
- 
+
-
-
-Notes on Timing
-
-
-M
-
-ransmission time on the radio medium. In these calculations, we assume a
-contention window 
+==========================
+
+m
+ transmission
+ime on the radio medium. In these calculations, we assume a contention window
+
-
-Further, calculation of the transmission time is required so that we can
-
-
-is 
+  The
+
+
-
-Indeed, the card will supply the cwmin/cwmax values directly
- iwpriv if_name get_cwmin <0|1|2|3> <0|1>
-
-
-or future work. Indeed, the cwmin/cwmax determination code could check to
-see if 
-
-
-video 
+ for
+uture work. Indeed, the cwmin/cwmax determination code could check to see if
+
+
+ video
+
-respectively. Currently, minstrel does not check traffic class.
-
-
-variable packet size will significantly complicate the code and requi
-
-
-(but reasonable) 
+ variable
+packet size will significantly complicate the code and require many mo
+
+
+
-
-
@@ -292 +295 @@
-
-Internal variable reporting
-
+
+
-The minstrel algorithm reports to the proc file system its internal
-statistics, which can be viewed as text. A sample output is below:
@@ -326 +330 @@
-T, t, and P respectively.
-
-
+ 
-"this prob" and "this succ/attempt" columns.
-
@@ -335 +339 @@
-analysing reports from the hal. The word "attempt" or "attempts" means the
-count of packets that we transmitted. Thus, the number in the success column
-
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