2014-04-14 14:04:05

by Antonio Quartulli

[permalink] [raw]
Subject: [PATCH 1/7] cfg80211: export expected throughput through get_station()

From: Antonio Quartulli <[email protected]>

Users may need information about the expected throughput
towards a given peer computed by the RC algorithm.
Export such value in Mbps/100 through the get_station() API.
This unit has been chosen because it is the same of the
throughput returned by MinstrelHT.

This information will be useful to the batman-adv module
which will use it for its new metric computation.

Signed-off-by: Antonio Quartulli <[email protected]>
---

Changes since the RFC:
- Change all the station_info_flags to use BIT()
- Properly comment about the unit used by the throughput value
- added new ieee80211_ops.get_expected_throughput() API (to support drivers
having HW RC)
- improved doc about new cfg80211_get_station() function
- minor cleanups


include/net/cfg80211.h | 63 ++++++++++++++++++++++++++++----------------------
1 file changed, 35 insertions(+), 28 deletions(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 9496fe5..d4b85f7 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -862,36 +862,38 @@ int cfg80211_check_station_change(struct wiphy *wiphy,
* @STATION_INFO_NONPEER_PM: @nonpeer_pm filled
* @STATION_INFO_CHAIN_SIGNAL: @chain_signal filled
* @STATION_INFO_CHAIN_SIGNAL_AVG: @chain_signal_avg filled
+ * @STATION_INFO_EXPECTED_THROUGHPUT: @expected_throughput filled
*/
enum station_info_flags {
- STATION_INFO_INACTIVE_TIME = 1<<0,
- STATION_INFO_RX_BYTES = 1<<1,
- STATION_INFO_TX_BYTES = 1<<2,
- STATION_INFO_LLID = 1<<3,
- STATION_INFO_PLID = 1<<4,
- STATION_INFO_PLINK_STATE = 1<<5,
- STATION_INFO_SIGNAL = 1<<6,
- STATION_INFO_TX_BITRATE = 1<<7,
- STATION_INFO_RX_PACKETS = 1<<8,
- STATION_INFO_TX_PACKETS = 1<<9,
- STATION_INFO_TX_RETRIES = 1<<10,
- STATION_INFO_TX_FAILED = 1<<11,
- STATION_INFO_RX_DROP_MISC = 1<<12,
- STATION_INFO_SIGNAL_AVG = 1<<13,
- STATION_INFO_RX_BITRATE = 1<<14,
- STATION_INFO_BSS_PARAM = 1<<15,
- STATION_INFO_CONNECTED_TIME = 1<<16,
- STATION_INFO_ASSOC_REQ_IES = 1<<17,
- STATION_INFO_STA_FLAGS = 1<<18,
- STATION_INFO_BEACON_LOSS_COUNT = 1<<19,
- STATION_INFO_T_OFFSET = 1<<20,
- STATION_INFO_LOCAL_PM = 1<<21,
- STATION_INFO_PEER_PM = 1<<22,
- STATION_INFO_NONPEER_PM = 1<<23,
- STATION_INFO_RX_BYTES64 = 1<<24,
- STATION_INFO_TX_BYTES64 = 1<<25,
- STATION_INFO_CHAIN_SIGNAL = 1<<26,
- STATION_INFO_CHAIN_SIGNAL_AVG = 1<<27,
+ STATION_INFO_INACTIVE_TIME = BIT(0),
+ STATION_INFO_RX_BYTES = BIT(1),
+ STATION_INFO_TX_BYTES = BIT(2),
+ STATION_INFO_LLID = BIT(3),
+ STATION_INFO_PLID = BIT(4),
+ STATION_INFO_PLINK_STATE = BIT(5),
+ STATION_INFO_SIGNAL = BIT(6),
+ STATION_INFO_TX_BITRATE = BIT(7),
+ STATION_INFO_RX_PACKETS = BIT(8),
+ STATION_INFO_TX_PACKETS = BIT(9),
+ STATION_INFO_TX_RETRIES = BIT(10),
+ STATION_INFO_TX_FAILED = BIT(11),
+ STATION_INFO_RX_DROP_MISC = BIT(12),
+ STATION_INFO_SIGNAL_AVG = BIT(13),
+ STATION_INFO_RX_BITRATE = BIT(14),
+ STATION_INFO_BSS_PARAM = BIT(15),
+ STATION_INFO_CONNECTED_TIME = BIT(16),
+ STATION_INFO_ASSOC_REQ_IES = BIT(17),
+ STATION_INFO_STA_FLAGS = BIT(18),
+ STATION_INFO_BEACON_LOSS_COUNT = BIT(19),
+ STATION_INFO_T_OFFSET = BIT(20),
+ STATION_INFO_LOCAL_PM = BIT(21),
+ STATION_INFO_PEER_PM = BIT(22),
+ STATION_INFO_NONPEER_PM = BIT(23),
+ STATION_INFO_RX_BYTES64 = BIT(24),
+ STATION_INFO_TX_BYTES64 = BIT(25),
+ STATION_INFO_CHAIN_SIGNAL = BIT(26),
+ STATION_INFO_CHAIN_SIGNAL_AVG = BIT(27),
+ STATION_INFO_EXPECTED_THROUGHPUT = BIT(28),
};

/**
@@ -1013,6 +1015,9 @@ struct sta_bss_parameters {
* @local_pm: local mesh STA power save mode
* @peer_pm: peer mesh STA power save mode
* @nonpeer_pm: non-peer mesh STA power save mode
+ * @expected_throughput: expected throughput in Mbps/100 reported by the RC
+ * algorithm towards this station. The unit of this value has been chosen
+ * because it is the same of the throughput returned by MinstrelHT
*/
struct station_info {
u32 filled;
@@ -1051,6 +1056,8 @@ struct station_info {
enum nl80211_mesh_power_mode peer_pm;
enum nl80211_mesh_power_mode nonpeer_pm;

+ u32 expected_throughput;
+
/*
* Note: Add a new enum station_info_flags value for each new field and
* use it to check which fields are initialized.
--
1.8.3.2



2014-04-25 15:45:35

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH 3/7] mac80211: add new RC API to retrieve expected throughput

On Mon, 2014-04-14 at 16:03 +0200, Antonio Quartulli wrote:
> From: Antonio Quartulli <[email protected]>
>
> In order to make mac80211 export the expected throughput,
> a new API which extracts such information from any mac80211
> SW RC algorithm is needed.
> Therefore add the new get_expected_throughput() member
> to the rate_control_ops structure.
>
> The exported value is expressed in Mbps/100. Such unit has
> been chosen because it is the highest precision that
> MinstrelHT can return.

Same as in patch 2 - and realistically 2/3/4 could just be squashed.

johannes


2014-04-18 00:56:21

by Chun-Yeow Yeoh

[permalink] [raw]
Subject: Re: [B.A.T.M.A.N.] [PATCH 2/7] mac80211: add get_expected_throughput API

Hi, Antonio

Do you know whether the calculation of expected throughput in minstrel
and minstrel_ht are both the same?

Any explanation on how the expected throughput is calculated?

---
Chun-Yeow

On Mon, Apr 14, 2014 at 10:03 PM, Antonio Quartulli
<[email protected]> wrote:
> From: Antonio Quartulli <[email protected]>
>
> Add get_expected_throughput() API to mac80211 so that each
> driver can implement its own version based on the RC
> algorithm they are using (might be using an HW RC algo).
> The API returns a value expressed in Mbps/100.
> This unit has been chosen because it is the same of the
> throughput returned by MinstrelHT.
>
> Signed-off-by: Antonio Quartulli <[email protected]>
> ---
> include/net/mac80211.h | 4 ++++
> net/mac80211/driver-ops.h | 13 +++++++++++++
> net/mac80211/trace.h | 32 ++++++++++++++++++++++++++++++++
> 3 files changed, 49 insertions(+)
>
> diff --git a/include/net/mac80211.h b/include/net/mac80211.h
> index a3044e1..0efe37c 100644
> --- a/include/net/mac80211.h
> +++ b/include/net/mac80211.h
> @@ -2761,6 +2761,9 @@ enum ieee80211_roc_type {
> * information in bss_conf is set up and the beacon can be retrieved. A
> * channel context is bound before this is called.
> * @leave_ibss: Leave the IBSS again.
> + *
> + * @get_expected_throughput: extract the expected throughput towards the
> + * specified station. The returned value is expressed in Mbps/100.
> */
> struct ieee80211_ops {
> void (*tx)(struct ieee80211_hw *hw,
> @@ -2954,6 +2957,7 @@ struct ieee80211_ops {
>
> int (*join_ibss)(struct ieee80211_hw *hw, struct ieee80211_vif *vif);
> void (*leave_ibss)(struct ieee80211_hw *hw, struct ieee80211_vif *vif);
> + u32 (*get_expected_throughput)(struct ieee80211_sta *sta);
> };
>
> /**
> diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
> index 5331582..84ee6c2 100644
> --- a/net/mac80211/driver-ops.h
> +++ b/net/mac80211/driver-ops.h
> @@ -1122,4 +1122,17 @@ static inline void drv_leave_ibss(struct ieee80211_local *local,
> trace_drv_return_void(local);
> }
>
> +static inline u32 drv_get_expected_throughput(struct ieee80211_local *local,
> + struct ieee80211_sta *sta)
> +{
> + u32 ret = 0;
> +
> + trace_drv_get_expected_throughput(sta);
> + if (local->ops->get_expected_throughput)
> + ret = local->ops->get_expected_throughput(sta);
> + trace_drv_return_u32(local, ret);
> +
> + return ret;
> +}
> +
> #endif /* __MAC80211_DRIVER_OPS */
> diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h
> index a0b0aea..942f64b 100644
> --- a/net/mac80211/trace.h
> +++ b/net/mac80211/trace.h
> @@ -184,6 +184,20 @@ TRACE_EVENT(drv_return_bool,
> "true" : "false")
> );
>
> +TRACE_EVENT(drv_return_u32,
> + TP_PROTO(struct ieee80211_local *local, u32 ret),
> + TP_ARGS(local, ret),
> + TP_STRUCT__entry(
> + LOCAL_ENTRY
> + __field(u32, ret)
> + ),
> + TP_fast_assign(
> + LOCAL_ASSIGN;
> + __entry->ret = ret;
> + ),
> + TP_printk(LOCAL_PR_FMT " - %u", LOCAL_PR_ARG, __entry->ret)
> +);
> +
> TRACE_EVENT(drv_return_u64,
> TP_PROTO(struct ieee80211_local *local, u64 ret),
> TP_ARGS(local, ret),
> @@ -1499,6 +1513,24 @@ DEFINE_EVENT(local_sdata_evt, drv_leave_ibss,
> TP_ARGS(local, sdata)
> );
>
> +TRACE_EVENT(drv_get_expected_throughput,
> + TP_PROTO(struct ieee80211_sta *sta),
> +
> + TP_ARGS(sta),
> +
> + TP_STRUCT__entry(
> + STA_ENTRY
> + ),
> +
> + TP_fast_assign(
> + STA_ASSIGN;
> + ),
> +
> + TP_printk(
> + STA_PR_FMT, STA_PR_ARG
> + )
> +);
> +
> /*
> * Tracing for API calls that drivers call.
> */
> --
> 1.8.3.2
>

2014-04-14 14:04:05

by Antonio Quartulli

[permalink] [raw]
Subject: [PATCH 4/7] mac80211: export expected throughput in set_sta_info()

From: Antonio Quartulli <[email protected]>

If either the driver or the SW RC algorithm implements the
get_expected_throughput() API fill the related member in the
station_info object when dumping a station.

Signed-off-by: Antonio Quartulli <[email protected]>
---
net/mac80211/cfg.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index aa39381..31d1955 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -472,8 +472,12 @@ static void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
struct ieee80211_local *local = sdata->local;
+ struct rate_control_ref *ref = local->rate_ctrl;
+ struct ieee80211_supported_band *sband;
+ enum ieee80211_band band;
struct timespec uptime;
u64 packets = 0;
+ u32 thr = 0;
int i, ac;

sinfo->generation = sdata->local->sta_generation;
@@ -587,6 +591,23 @@ static void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
sinfo->sta_flags.set |= BIT(NL80211_STA_FLAG_ASSOCIATED);
if (test_sta_flag(sta, WLAN_STA_TDLS_PEER))
sinfo->sta_flags.set |= BIT(NL80211_STA_FLAG_TDLS_PEER);
+
+ /* check if the driver has a SW RC implementation */
+ if (ref && ref->ops->get_expected_throughput) {
+ band = ieee80211_get_sdata_band(sta->sdata);
+ sband = sta->local->hw.wiphy->bands[band];
+
+ thr = ref->ops->get_expected_throughput(ref->priv,
+ sta->rate_ctrl_priv,
+ sband);
+ } else {
+ thr = drv_get_expected_throughput(local, &sta->sta);
+ }
+
+ if (thr != 0) {
+ sinfo->filled |= STATION_INFO_EXPECTED_THROUGHPUT;
+ sinfo->expected_throughput = thr;
+ }
}

static const char ieee80211_gstrings_sta_stats[][ETH_GSTRING_LEN] = {
--
1.8.3.2


2014-04-25 15:48:33

by Antonio Quartulli

[permalink] [raw]
Subject: Re: [PATCH 5/7] mac80211: minstrel - implement get_expected_throughput() API



On 25/04/14 17:46, Johannes Berg wrote:
> On Mon, 2014-04-14 at 16:03 +0200, Antonio Quartulli wrote:
>> From: Antonio Quartulli <[email protected]>
>>
>> Cc: Felix Fietkau <[email protected]>
>> Signed-off-by: Antonio Quartulli <[email protected]>
>> ---
>> net/mac80211/rc80211_minstrel.c | 13 +++++++++++++
>> 1 file changed, 13 insertions(+)
>>
>> diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
>> index 26fd94f..cd40bc0 100644
>> --- a/net/mac80211/rc80211_minstrel.c
>> +++ b/net/mac80211/rc80211_minstrel.c
>> @@ -657,6 +657,18 @@ minstrel_free(void *priv)
>> kfree(priv);
>> }
>>
>> +static u32
>> +minstrel_get_expected_throughput(void *priv, void *priv_sta,
>> + struct ieee80211_supported_band *sband)
>> +{
>> + struct minstrel_sta_info *mi = priv_sta;
>> + int idx = mi->max_tp_rate[0];
>> + u32 bitrate, ret;
>> +
>> + bitrate = sband->bitrates[mi->r[idx].rix].bitrate;
>> + return bitrate * MINSTREL_TRUNC(mi->r[idx].probability * 1000) / 100;
>
> /100? didn't you say minstrel already used your units?

MinstrelHT does, Minstrel does not...

Cheers,

--
Antonio Quartulli


Attachments:
signature.asc (901.00 B)
OpenPGP digital signature

2014-04-14 14:04:06

by Antonio Quartulli

[permalink] [raw]
Subject: [PATCH 6/7] mac80211: minstrel_ht - implement get_expected_throughput() API

From: Antonio Quartulli <[email protected]>

Cc: Felix Fietkau <[email protected]>
Signed-off-by: Antonio Quartulli <[email protected]>
---
net/mac80211/rc80211_minstrel_ht.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index bccaf85..480f657 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -1031,6 +1031,24 @@ minstrel_ht_free(void *priv)
mac80211_minstrel.free(priv);
}

+static u32
+minstrel_ht_get_expected_throughput(void *priv, void *priv_sta,
+ struct ieee80211_supported_band *sband)
+{
+ struct minstrel_ht_sta_priv *msp = priv_sta;
+ struct minstrel_ht_sta *mi = &msp->ht;
+ int i, j;
+
+ if (!msp->is_ht)
+ return mac80211_minstrel.get_expected_throughput(priv, priv_sta,
+ sband);
+
+ i = mi->max_tp_rate / MCS_GROUP_RATES;
+ j = mi->max_tp_rate % MCS_GROUP_RATES;
+
+ return mi->groups[i].rates[j].cur_tp;
+}
+
static const struct rate_control_ops mac80211_minstrel_ht = {
.name = "minstrel_ht",
.tx_status = minstrel_ht_tx_status,
@@ -1045,6 +1063,7 @@ static const struct rate_control_ops mac80211_minstrel_ht = {
.add_sta_debugfs = minstrel_ht_add_sta_debugfs,
.remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
#endif
+ .get_expected_throughput = minstrel_ht_get_expected_throughput,
};


--
1.8.3.2


2014-04-25 15:45:19

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH 2/7] mac80211: add get_expected_throughput API

On Mon, 2014-04-14 at 16:03 +0200, Antonio Quartulli wrote:

> + u32 (*get_expected_throughput)(struct ieee80211_sta *sta);

This isn't nice - it forces drivers to conjure up a value.

You should probably at least allow returning 0 for "no idea" or
something.

johannes



2014-04-14 14:04:07

by Antonio Quartulli

[permalink] [raw]
Subject: [PATCH 7/7] cfg80211: implement cfg80211_get_station cfg80211 API

From: Antonio Quartulli <[email protected]>

Implement and export the new cfg80211_get_station() API.
This utility can be used by other kernel modules to obtain
detailed information about a given wireless station.

It will be in particular useful to batman-adv which will
implement a wireless rate based metric.

Signed-off-by: Antonio Quartulli <[email protected]>
---
include/net/cfg80211.h | 13 +++++++++++++
net/wireless/util.c | 18 ++++++++++++++++++
2 files changed, 31 insertions(+)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index d4b85f7..c890244 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1065,6 +1065,19 @@ struct station_info {
};

/**
+ * cfg80211_get_station - retrieve information about a given station
+ * @dev: the device where the station is supposed to be connected to
+ * @mac_addr: the mac address of the station of interest
+ * @sinfo: pointer to the structure to fill with the information
+ *
+ * Returns 0 on success and sinfo is filled with the available information
+ * otherwise returns a negative error code and the content of sinfo has to be
+ * considered undefined.
+ */
+int cfg80211_get_station(struct net_device *dev, const u8 *mac_addr,
+ struct station_info *sinfo);
+
+/**
* enum monitor_flags - monitor flags
*
* Monitor interface configuration flags. Note that these must be the bits
diff --git a/net/wireless/util.c b/net/wireless/util.c
index d032a31..d84d61a 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1498,6 +1498,24 @@ unsigned int ieee80211_get_num_supported_channels(struct wiphy *wiphy)
}
EXPORT_SYMBOL(ieee80211_get_num_supported_channels);

+int cfg80211_get_station(struct net_device *dev, const u8 *mac_addr,
+ struct station_info *sinfo)
+{
+ struct cfg80211_registered_device *rdev;
+ struct wireless_dev *wdev;
+
+ wdev = dev->ieee80211_ptr;
+ if (!wdev)
+ return -EOPNOTSUPP;
+
+ rdev = wiphy_to_dev(wdev->wiphy);
+ if (!rdev->ops->get_station)
+ return -EOPNOTSUPP;
+
+ return rdev_get_station(rdev, dev, mac_addr, sinfo);
+}
+EXPORT_SYMBOL(cfg80211_get_station);
+
/* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
const unsigned char rfc1042_header[] __aligned(2) =
--
1.8.3.2


2014-04-14 14:04:05

by Antonio Quartulli

[permalink] [raw]
Subject: [PATCH 3/7] mac80211: add new RC API to retrieve expected throughput

From: Antonio Quartulli <[email protected]>

In order to make mac80211 export the expected throughput,
a new API which extracts such information from any mac80211
SW RC algorithm is needed.
Therefore add the new get_expected_throughput() member
to the rate_control_ops structure.

The exported value is expressed in Mbps/100. Such unit has
been chosen because it is the highest precision that
MinstrelHT can return.

Signed-off-by: Antonio Quartulli <[email protected]>
---
include/net/mac80211.h | 3 +++
1 file changed, 3 insertions(+)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 0efe37c..47b891a 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -4480,6 +4480,9 @@ struct rate_control_ops {
void (*add_sta_debugfs)(void *priv, void *priv_sta,
struct dentry *dir);
void (*remove_sta_debugfs)(void *priv, void *priv_sta);
+
+ u32 (*get_expected_throughput)(void *priv, void *priv_sta,
+ struct ieee80211_supported_band *sband);
};

static inline int rate_supported(struct ieee80211_sta *sta,
--
1.8.3.2


2014-04-25 15:47:16

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH 7/7] cfg80211: implement cfg80211_get_station cfg80211 API


> + rdev = wiphy_to_dev(wdev->wiphy);

That's _to_rdev() now.

johannes



2014-04-14 17:54:53

by Bastian Bittorf

[permalink] [raw]
Subject: Re: [B.A.T.M.A.N.] [PATCH 2/7] mac80211: add get_expected_throughput API

* Antonio Quartulli <[email protected]> [14.04.2014 16:53]:
> From: Antonio Quartulli <[email protected]>
>
> Add get_expected_throughput() API to mac80211 so that each
> driver can implement its own version based on the RC

Without understanding this fully: thank you.

What is not clear to me: the function returns Mbps/100.
Why not simply kilobit/second?

Also: does it return expected_goodput or "only" throughput?
Because we want to use this value not internally only it should
reflect the real usecase (and should also be human-readable).

For a meshnet it is important to know, that a 10mbit ethernet line
is faster than a 60 mbit wireless link with a low tx-probability.

bye, Bastian Bittorf

2014-04-25 15:44:27

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH 1/7] cfg80211: export expected throughput through get_station()

On Mon, 2014-04-14 at 16:03 +0200, Antonio Quartulli wrote:
> From: Antonio Quartulli <[email protected]>
>
> Users may need information about the expected throughput

I think this "expected throughput" should be a bit clarified.

Are you talking about "expected PHY rate" or rather "expected (payload)
throughput"?

> towards a given peer computed by the RC algorithm.
> Export such value in Mbps/100 through the get_station() API.

"units of 10Kbps" might be a better description :-)

> This unit has been chosen because it is the same of the
> throughput returned by MinstrelHT.

Since it's unlikely we'll ever reach the limit of a u32, maybe just
multiply by 10 to get the nicer Kbps?

> + * @expected_throughput: expected throughput in Mbps/100 reported by the RC
> + * algorithm towards this station. The unit of this value has been chosen
> + * because it is the same of the throughput returned by MinstrelHT

I think the rationale shouldn't be here now.

johannes


2014-04-18 06:20:08

by Antonio Quartulli

[permalink] [raw]
Subject: Re: [B.A.T.M.A.N.] [PATCH 2/7] mac80211: add get_expected_throughput API



On 18/04/14 02:56, Yeoh Chun-Yeow wrote:
> Hi, Antonio
>
> Do you know whether the calculation of expected throughput in minstrel
> and minstrel_ht are both the same?

not really the same, but they are similar.

>
> Any explanation on how the expected throughput is calculated?

Just check patch 5 and 6 :)

Cheers,


--
Antonio Quartulli


Attachments:
signature.asc (901.00 B)
OpenPGP digital signature

2014-04-25 15:46:28

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH 5/7] mac80211: minstrel - implement get_expected_throughput() API

On Mon, 2014-04-14 at 16:03 +0200, Antonio Quartulli wrote:
> From: Antonio Quartulli <[email protected]>
>
> Cc: Felix Fietkau <[email protected]>
> Signed-off-by: Antonio Quartulli <[email protected]>
> ---
> net/mac80211/rc80211_minstrel.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
> index 26fd94f..cd40bc0 100644
> --- a/net/mac80211/rc80211_minstrel.c
> +++ b/net/mac80211/rc80211_minstrel.c
> @@ -657,6 +657,18 @@ minstrel_free(void *priv)
> kfree(priv);
> }
>
> +static u32
> +minstrel_get_expected_throughput(void *priv, void *priv_sta,
> + struct ieee80211_supported_band *sband)
> +{
> + struct minstrel_sta_info *mi = priv_sta;
> + int idx = mi->max_tp_rate[0];
> + u32 bitrate, ret;
> +
> + bitrate = sband->bitrates[mi->r[idx].rix].bitrate;
> + return bitrate * MINSTREL_TRUNC(mi->r[idx].probability * 1000) / 100;

/100? didn't you say minstrel already used your units?

johannes


2014-04-14 14:04:05

by Antonio Quartulli

[permalink] [raw]
Subject: [PATCH 2/7] mac80211: add get_expected_throughput API

From: Antonio Quartulli <[email protected]>

Add get_expected_throughput() API to mac80211 so that each
driver can implement its own version based on the RC
algorithm they are using (might be using an HW RC algo).
The API returns a value expressed in Mbps/100.
This unit has been chosen because it is the same of the
throughput returned by MinstrelHT.

Signed-off-by: Antonio Quartulli <[email protected]>
---
include/net/mac80211.h | 4 ++++
net/mac80211/driver-ops.h | 13 +++++++++++++
net/mac80211/trace.h | 32 ++++++++++++++++++++++++++++++++
3 files changed, 49 insertions(+)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index a3044e1..0efe37c 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2761,6 +2761,9 @@ enum ieee80211_roc_type {
* information in bss_conf is set up and the beacon can be retrieved. A
* channel context is bound before this is called.
* @leave_ibss: Leave the IBSS again.
+ *
+ * @get_expected_throughput: extract the expected throughput towards the
+ * specified station. The returned value is expressed in Mbps/100.
*/
struct ieee80211_ops {
void (*tx)(struct ieee80211_hw *hw,
@@ -2954,6 +2957,7 @@ struct ieee80211_ops {

int (*join_ibss)(struct ieee80211_hw *hw, struct ieee80211_vif *vif);
void (*leave_ibss)(struct ieee80211_hw *hw, struct ieee80211_vif *vif);
+ u32 (*get_expected_throughput)(struct ieee80211_sta *sta);
};

/**
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index 5331582..84ee6c2 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -1122,4 +1122,17 @@ static inline void drv_leave_ibss(struct ieee80211_local *local,
trace_drv_return_void(local);
}

+static inline u32 drv_get_expected_throughput(struct ieee80211_local *local,
+ struct ieee80211_sta *sta)
+{
+ u32 ret = 0;
+
+ trace_drv_get_expected_throughput(sta);
+ if (local->ops->get_expected_throughput)
+ ret = local->ops->get_expected_throughput(sta);
+ trace_drv_return_u32(local, ret);
+
+ return ret;
+}
+
#endif /* __MAC80211_DRIVER_OPS */
diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h
index a0b0aea..942f64b 100644
--- a/net/mac80211/trace.h
+++ b/net/mac80211/trace.h
@@ -184,6 +184,20 @@ TRACE_EVENT(drv_return_bool,
"true" : "false")
);

+TRACE_EVENT(drv_return_u32,
+ TP_PROTO(struct ieee80211_local *local, u32 ret),
+ TP_ARGS(local, ret),
+ TP_STRUCT__entry(
+ LOCAL_ENTRY
+ __field(u32, ret)
+ ),
+ TP_fast_assign(
+ LOCAL_ASSIGN;
+ __entry->ret = ret;
+ ),
+ TP_printk(LOCAL_PR_FMT " - %u", LOCAL_PR_ARG, __entry->ret)
+);
+
TRACE_EVENT(drv_return_u64,
TP_PROTO(struct ieee80211_local *local, u64 ret),
TP_ARGS(local, ret),
@@ -1499,6 +1513,24 @@ DEFINE_EVENT(local_sdata_evt, drv_leave_ibss,
TP_ARGS(local, sdata)
);

+TRACE_EVENT(drv_get_expected_throughput,
+ TP_PROTO(struct ieee80211_sta *sta),
+
+ TP_ARGS(sta),
+
+ TP_STRUCT__entry(
+ STA_ENTRY
+ ),
+
+ TP_fast_assign(
+ STA_ASSIGN;
+ ),
+
+ TP_printk(
+ STA_PR_FMT, STA_PR_ARG
+ )
+);
+
/*
* Tracing for API calls that drivers call.
*/
--
1.8.3.2


2014-04-14 14:04:06

by Antonio Quartulli

[permalink] [raw]
Subject: [PATCH 5/7] mac80211: minstrel - implement get_expected_throughput() API

From: Antonio Quartulli <[email protected]>

Cc: Felix Fietkau <[email protected]>
Signed-off-by: Antonio Quartulli <[email protected]>
---
net/mac80211/rc80211_minstrel.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index 26fd94f..cd40bc0 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -657,6 +657,18 @@ minstrel_free(void *priv)
kfree(priv);
}

+static u32
+minstrel_get_expected_throughput(void *priv, void *priv_sta,
+ struct ieee80211_supported_band *sband)
+{
+ struct minstrel_sta_info *mi = priv_sta;
+ int idx = mi->max_tp_rate[0];
+ u32 bitrate, ret;
+
+ bitrate = sband->bitrates[mi->r[idx].rix].bitrate;
+ return bitrate * MINSTREL_TRUNC(mi->r[idx].probability * 1000) / 100;
+}
+
const struct rate_control_ops mac80211_minstrel = {
.name = "minstrel",
.tx_status = minstrel_tx_status,
@@ -670,6 +682,7 @@ const struct rate_control_ops mac80211_minstrel = {
.add_sta_debugfs = minstrel_add_sta_debugfs,
.remove_sta_debugfs = minstrel_remove_sta_debugfs,
#endif
+ .get_expected_throughput = minstrel_get_expected_throughput,
};

int __init
--
1.8.3.2


2014-05-14 21:16:06

by Antonio Quartulli

[permalink] [raw]
Subject: Re: [PATCH 3/7] mac80211: add new RC API to retrieve expected throughput



On 25/04/14 17:45, Johannes Berg wrote:
> On Mon, 2014-04-14 at 16:03 +0200, Antonio Quartulli wrote:
>> From: Antonio Quartulli <[email protected]>
>>
>> In order to make mac80211 export the expected throughput,
>> a new API which extracts such information from any mac80211
>> SW RC algorithm is needed.
>> Therefore add the new get_expected_throughput() member
>> to the rate_control_ops structure.
>>
>> The exported value is expressed in Mbps/100. Such unit has
>> been chosen because it is the highest precision that
>> MinstrelHT can return.
>
> Same as in patch 2 - and realistically 2/3/4 could just be squashed.
>

Yeah, I will specify the 0 value as "I don't know what to provide" and I
think it is fine to have just one patch.

--
Antonio Quartulli


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2014-05-14 21:16:33

by Antonio Quartulli

[permalink] [raw]
Subject: Re: [PATCH 7/7] cfg80211: implement cfg80211_get_station cfg80211 API



On 25/04/14 17:46, Johannes Berg wrote:
>
>> + rdev = wiphy_to_dev(wdev->wiphy);
>
> That's _to_rdev() now.

Thanks, will fix that.

--
Antonio Quartulli


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2014-05-14 21:29:04

by Antonio Quartulli

[permalink] [raw]
Subject: Re: [PATCH 1/7] cfg80211: export expected throughput through get_station()

On 25/04/14 17:44, Johannes Berg wrote:
> On Mon, 2014-04-14 at 16:03 +0200, Antonio Quartulli wrote:
>> From: Antonio Quartulli <[email protected]>
>>
>> Users may need information about the expected throughput
>
> I think this "expected throughput" should be a bit clarified.
>
> Are you talking about "expected PHY rate" or rather "expected (payload)
> throughput"?

It is not payload throughput because in this "number" we also consider
the bytes being part of the 802.11 Header. Maybe we can call it
"expected MAC throughput" ?


>
>> towards a given peer computed by the RC algorithm.
>> Export such value in Mbps/100 through the get_station() API.
>
> "units of 10Kbps" might be a better description :-)
>
>> This unit has been chosen because it is the same of the
>> throughput returned by MinstrelHT.
>
> Since it's unlikely we'll ever reach the limit of a u32, maybe just
> multiply by 10 to get the nicer Kbps?

At least we are safe in the near future :) Ok, I can change it to Kbps
because it seems that a lot of people will be happier :)

>
>> + * @expected_throughput: expected throughput in Mbps/100 reported by the RC
>> + * algorithm towards this station. The unit of this value has been chosen
>> + * because it is the same of the throughput returned by MinstrelHT
>
> I think the rationale shouldn't be here now.
>

I think I will just remove the last sentence.


Thanks a lot!

--
Antonio Quartulli


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2014-05-14 21:11:03

by Antonio Quartulli

[permalink] [raw]
Subject: Re: [PATCH 2/7] mac80211: add get_expected_throughput API

On 25/04/14 17:44, Johannes Berg wrote:
> On Mon, 2014-04-14 at 16:03 +0200, Antonio Quartulli wrote:
>
>> + u32 (*get_expected_throughput)(struct ieee80211_sta *sta);
>
> This isn't nice - it forces drivers to conjure up a value.
>
> You should probably at least allow returning 0 for "no idea" or
> something.

Yeah, I think so too. Returning 0 as "I don't know what to provide"
should be fine. I will specify this in the doc.


Cheers,

--
Antonio Quartulli


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