[v5,6/7] batman-adv: ELP - use tp meter to estimate the throughput if otherwise not available

Message ID 20180907095958.30946-7-mareklindner@neomailbox.ch
State New
Delegated to: Simon Wunderlich
Headers show
Series
  • B.A.T.M.A.N. V - fallback to tp meter estimation if throughput otherwise not available
Related show

Commit Message

Marek Lindner Sept. 7, 2018, 9:59 a.m.
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
---
 net/batman-adv/bat_v_elp.c | 67 ++++++++++++++++++++++++++++++++++++--
 net/batman-adv/bat_v_elp.h | 21 ++++++++++++
 net/batman-adv/main.h      |  1 +
 net/batman-adv/tp_meter.c  | 41 ++++++++++++++++++-----
 net/batman-adv/types.h     | 14 ++++++++
 5 files changed, 133 insertions(+), 11 deletions(-)

Comments

Sven Eckelmann Sept. 8, 2018, 5:11 p.m. | #1
On Freitag, 7. September 2018 11:59:57 CEST Marek Lindner wrote:
> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
> ---

Most patches in the patchset have quite long patch summary phrase [1]. And 
this one here (and the patch 3)  doesn't have a commit message at all.

Wouldn't it be better to have some actual message and a more brief+precise 
subject

    batman-adv: ELP - Fall back to tpmeter for throughput estimation

    ... when nothing works ... blablabla .. better than nothing ... blublub
    under following conditions ...
    done every ...
    more text here
    ...

(actual info has to be added and the subject can be better then the example 
one here).

Kind regards,
	Sven

[1] https://www.kernel.org/doc/html/v4.17/process/submitting-patches.html#the-canonical-patch-format

Patch

diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c
index e103c759..6e700fcf 100644
--- a/net/batman-adv/bat_v_elp.c
+++ b/net/batman-adv/bat_v_elp.c
@@ -51,6 +51,7 @@ 
 #include "originator.h"
 #include "routing.h"
 #include "send.h"
+#include "tp_meter.h"
 
 /**
  * batadv_v_elp_start_timer() - restart timer for ELP periodic work
@@ -67,6 +68,42 @@  static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface)
 			   msecs_to_jiffies(msecs));
 }
 
+/**
+ * batadv_v_elp_tp_start() - start a tp meter session for a neighbor
+ * @neigh: neighbor to run tp meter on
+ */
+static void batadv_v_elp_tp_start(struct batadv_hardif_neigh_node *neigh)
+{
+	struct batadv_hard_iface *hard_iface = neigh->if_incoming;
+	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
+
+	neigh->bat_v.tp_meter_running = true;
+	batadv_tp_start(bat_priv, neigh->addr, neigh,
+			1000, NULL, BATADV_TP_ELP);
+}
+
+/**
+ * batadv_v_elp_tp_fail() - handle tp meter session failure
+ * @neigh: neighbor to run tp meter on
+ */
+void batadv_v_elp_tp_fail(struct batadv_hardif_neigh_node *neigh)
+{
+	neigh->bat_v.tp_meter_running = false;
+}
+
+/**
+ * batadv_v_elp_tp_finish() - post-process tp meter results
+ * @neigh: neighbor tp meter on
+ * @throughput: tp meter throughput result
+ */
+void batadv_v_elp_tp_finish(struct batadv_hardif_neigh_node *neigh,
+			    u32 throughput)
+{
+	neigh->bat_v.tp_meter_throughput = throughput;
+	neigh->bat_v.last_tp_meter_run = jiffies;
+	neigh->bat_v.tp_meter_running = false;
+}
+
 /**
  * batadv_v_elp_get_throughput() - get the throughput towards a neighbour
  * @neigh: the neighbour for which the throughput has to be obtained
@@ -112,10 +149,13 @@  static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
 			 */
 			return 0;
 		}
+
+		/* unsupported WiFi driver */
 		if (ret)
-			goto default_throughput;
+			goto fallback_throughput;
+
 		if (!(sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT)))
-			goto default_throughput;
+			goto fallback_throughput;
 
 		return sinfo.expected_throughput / 100;
 	}
@@ -152,6 +192,29 @@  static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
 			return throughput * 10;
 	}
 
+fallback_throughput:
+	/* check the tp_meter_running flag before checking the timestamp to
+	 * avoid a race condition where a new tp meter session is scheduled
+	 * right after the previous tp meter session has completed.
+	 *
+	 * No lock is required because this is the only point where
+	 * batadv_v_elp_tp_start() is invoked and we get here only through a
+	 * periodic timer. This means we will never run this function
+	 * concurrently with itself.
+	 */
+	if (!neigh->bat_v.tp_meter_running &&
+	    batadv_has_timed_out(neigh->bat_v.last_tp_meter_run,
+				 BATADV_ELP_TP_RUN_INTERVAL))
+		batadv_v_elp_tp_start(neigh);
+
+	/* discard too old tp test results */
+	if (batadv_has_timed_out(neigh->bat_v.last_tp_meter_run,
+				 2 * BATADV_ELP_TP_RUN_INTERVAL))
+		neigh->bat_v.tp_meter_throughput = 0;
+
+	if (neigh->bat_v.tp_meter_throughput)
+		return neigh->bat_v.tp_meter_throughput;
+
 default_throughput:
 	if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) {
 		batadv_info(hard_iface->soft_iface,
diff --git a/net/batman-adv/bat_v_elp.h b/net/batman-adv/bat_v_elp.h
index e8c7b7fd..4ffb1fde 100644
--- a/net/batman-adv/bat_v_elp.h
+++ b/net/batman-adv/bat_v_elp.h
@@ -21,6 +21,8 @@ 
 
 #include "main.h"
 
+#include <linux/types.h>
+
 struct sk_buff;
 struct work_struct;
 
@@ -33,4 +35,23 @@  int batadv_v_elp_packet_recv(struct sk_buff *skb,
 			     struct batadv_hard_iface *if_incoming);
 void batadv_v_elp_throughput_metric_update(struct work_struct *work);
 
+#ifdef CONFIG_BATMAN_ADV_BATMAN_V
+
+void batadv_v_elp_tp_fail(struct batadv_hardif_neigh_node *neigh);
+void batadv_v_elp_tp_finish(struct batadv_hardif_neigh_node *neigh,
+			    u32 throughput);
+
+#else
+
+static inline void batadv_v_elp_tp_fail(struct batadv_hardif_neigh_node *neigh)
+{
+}
+
+static inline void
+batadv_v_elp_tp_finish(struct batadv_hardif_neigh_node *neigh, u32 throughput)
+{
+}
+
+#endif /* CONFIG_BATMAN_ADV_BATMAN_V */
+
 #endif /* _NET_BATMAN_ADV_BAT_V_ELP_H_ */
diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h
index 89dfaf87..ed4ae913 100644
--- a/net/batman-adv/main.h
+++ b/net/batman-adv/main.h
@@ -69,6 +69,7 @@ 
 #define BATADV_ELP_MIN_PROBE_SIZE 200 /* bytes */
 #define BATADV_ELP_PROBE_MAX_TX_DIFF 100 /* milliseconds */
 #define BATADV_ELP_MAX_AGE 64
+#define BATADV_ELP_TP_RUN_INTERVAL 60000 /* milliseconds */
 #define BATADV_OGM_MAX_ORIGDIFF 5
 #define BATADV_OGM_MAX_AGE 64
 
diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c
index f23bb847..96e03da0 100644
--- a/net/batman-adv/tp_meter.c
+++ b/net/batman-adv/tp_meter.c
@@ -24,7 +24,7 @@ 
 #include <linux/byteorder/generic.h>
 #include <linux/cache.h>
 #include <linux/compiler.h>
-#include <linux/err.h>
+#include <linux/errno.h>
 #include <linux/etherdevice.h>
 #include <linux/gfp.h>
 #include <linux/if_ether.h>
@@ -33,9 +33,9 @@ 
 #include <linux/kernel.h>
 #include <linux/kref.h>
 #include <linux/list.h>
+#include <linux/log2.h>
 #include <linux/netdevice.h>
 #include <linux/param.h>
-#include <linux/printk.h>
 #include <linux/random.h>
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
@@ -51,6 +51,7 @@ 
 #include <uapi/linux/batadv_packet.h>
 #include <uapi/linux/batman_adv.h>
 
+#include "bat_v_elp.h"
 #include "hard-interface.h"
 #include "log.h"
 #include "netlink.h"
@@ -224,7 +225,7 @@  static void batadv_tp_caller_notify(struct batadv_priv *bat_priv,
 				    struct batadv_tp_vars *tp_vars,
 				    enum batadv_tp_meter_reason reason)
 {
-	u32 total_bytes;
+	u64 total_bytes;
 	u32 test_time;
 	u32 cookie;
 	bool reason_is_error;
@@ -251,6 +252,24 @@  static void batadv_tp_caller_notify(struct batadv_priv *bat_priv,
 
 		break;
 	case BATADV_TP_ELP:
+		if (reason_is_error) {
+			batadv_v_elp_tp_fail(tp_vars->hardif_neigh);
+			return;
+		}
+
+		test_time = jiffies_to_msecs(jiffies - tp_vars->start_time);
+		if (!test_time) {
+			batadv_v_elp_tp_fail(tp_vars->hardif_neigh);
+			return;
+		}
+
+		/* The following calculation includes these steps:
+		 * - divide bytes by the test length (msecs)
+		 * - convert result from bits/ms to 0.1Mb/s (1Mb/s==1000000b/s)
+		 */
+		total_bytes = atomic64_read(&tp_vars->tot_sent);
+		do_div(total_bytes, test_time * 125);
+		batadv_v_elp_tp_finish(tp_vars->hardif_neigh, total_bytes);
 		break;
 	default:
 		break;
@@ -264,11 +283,14 @@  static void batadv_tp_caller_notify(struct batadv_priv *bat_priv,
  * @reason: reason for tp meter session stop
  * @dst: destination of tp_meter session
  * @cookie: cookie of tp_meter session
+ * @hardif_neigh: neighbor towards which the test was ran (for one-hop test)
  */
-static void batadv_tp_caller_init_error(struct batadv_priv *bat_priv,
-					enum batadv_tp_meter_caller caller,
-					enum batadv_tp_meter_reason reason,
-					const u8 *dst, u32 cookie)
+static void
+batadv_tp_caller_init_error(struct batadv_priv *bat_priv,
+			    enum batadv_tp_meter_caller caller,
+			    enum batadv_tp_meter_reason reason, const u8 *dst,
+			    u32 cookie,
+			    struct batadv_hardif_neigh_node *hardif_neigh)
 {
 	switch (caller) {
 	case BATADV_TP_USERSPACE:
@@ -276,6 +298,7 @@  static void batadv_tp_caller_init_error(struct batadv_priv *bat_priv,
 					      cookie);
 		break;
 	case BATADV_TP_ELP:
+		batadv_v_elp_tp_fail(hardif_neigh);
 		break;
 	default:
 		break;
@@ -971,7 +994,7 @@  void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst,
 			   "Meter: too many ongoing sessions, aborting (SEND)\n");
 		batadv_tp_caller_init_error(bat_priv, caller,
 					    BATADV_TP_REASON_TOO_MANY, dst,
-					    session_cookie);
+					    session_cookie, neigh);
 		return;
 	}
 
@@ -979,7 +1002,7 @@  void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst,
 	if (!tp_vars) {
 		batadv_tp_caller_init_error(bat_priv, caller,
 					    BATADV_TP_REASON_MEMORY_ERROR, dst,
-					    session_cookie);
+					    session_cookie, neigh);
 		return;
 	}
 
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index f72db6cf..fe763410 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -584,6 +584,20 @@  struct batadv_hardif_neigh_node_bat_v {
 
 	/** @metric_work: work queue callback item for metric update */
 	struct work_struct metric_work;
+
+	/**
+	 * @tp_meter_running: tp meter measurements towards this neighbor in
+	 * progress
+	 */
+	unsigned char tp_meter_running:1;
+
+	/**
+	 * @last_tp_meter_run: timestamp of last tp meter measurement completion
+	 */
+	unsigned long last_tp_meter_run;
+
+	/** @tp_meter_throughput: throughput information measured by tp meter */
+	unsigned long tp_meter_throughput;
 };
 
 /**