2012-03-18 21:58:29

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v2 1/3] cfg80211: use compare_ether_addr on MAC addresses instead of memcmp

Because of the constant size and guaranteed 16 bit alignment, the inline
compare_ether_addr function is much cheaper than calling memcmp.

Signed-off-by: Felix Fietkau <[email protected]>
---
net/wireless/mlme.c | 32 +++++++++++++++++---------------
net/wireless/scan.c | 2 +-
2 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index f5a7ac3..e14fdcc 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -6,6 +6,7 @@

#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/etherdevice.h>
#include <linux/netdevice.h>
#include <linux/nl80211.h>
#include <linux/slab.h>
@@ -100,7 +101,7 @@ void __cfg80211_send_deauth(struct net_device *dev,
ASSERT_WDEV_LOCK(wdev);

if (wdev->current_bss &&
- memcmp(wdev->current_bss->pub.bssid, bssid, ETH_ALEN) == 0) {
+ compare_ether_addr(wdev->current_bss->pub.bssid, bssid) == 0) {
cfg80211_unhold_bss(wdev->current_bss);
cfg80211_put_bss(&wdev->current_bss->pub);
wdev->current_bss = NULL;
@@ -115,7 +116,7 @@ void __cfg80211_send_deauth(struct net_device *dev,

reason_code = le16_to_cpu(mgmt->u.deauth.reason_code);

- from_ap = memcmp(mgmt->sa, dev->dev_addr, ETH_ALEN) != 0;
+ from_ap = compare_ether_addr(mgmt->sa, dev->dev_addr) != 0;
__cfg80211_disconnected(dev, NULL, 0, reason_code, from_ap);
} else if (wdev->sme_state == CFG80211_SME_CONNECTING) {
__cfg80211_connect_result(dev, mgmt->bssid, NULL, 0, NULL, 0,
@@ -154,7 +155,7 @@ void __cfg80211_send_disassoc(struct net_device *dev,
return;

if (wdev->current_bss &&
- memcmp(wdev->current_bss->pub.bssid, bssid, ETH_ALEN) == 0) {
+ compare_ether_addr(wdev->current_bss->pub.bssid, bssid) == 0) {
cfg80211_sme_disassoc(dev, wdev->current_bss);
cfg80211_unhold_bss(wdev->current_bss);
cfg80211_put_bss(&wdev->current_bss->pub);
@@ -165,7 +166,7 @@ void __cfg80211_send_disassoc(struct net_device *dev,

reason_code = le16_to_cpu(mgmt->u.disassoc.reason_code);

- from_ap = memcmp(mgmt->sa, dev->dev_addr, ETH_ALEN) != 0;
+ from_ap = compare_ether_addr(mgmt->sa, dev->dev_addr) != 0;
__cfg80211_disconnected(dev, NULL, 0, reason_code, from_ap);
}
EXPORT_SYMBOL(__cfg80211_send_disassoc);
@@ -285,7 +286,7 @@ int __cfg80211_mlme_auth(struct cfg80211_registered_device *rdev,
return -EINVAL;

if (wdev->current_bss &&
- memcmp(bssid, wdev->current_bss->pub.bssid, ETH_ALEN) == 0)
+ compare_ether_addr(bssid, wdev->current_bss->pub.bssid) == 0)
return -EALREADY;

memset(&req, 0, sizeof(req));
@@ -362,7 +363,7 @@ int __cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
memset(&req, 0, sizeof(req));

if (wdev->current_bss && prev_bssid &&
- memcmp(wdev->current_bss->pub.bssid, prev_bssid, ETH_ALEN) == 0) {
+ compare_ether_addr(wdev->current_bss->pub.bssid, prev_bssid) == 0) {
/*
* Trying to reassociate: Allow this to proceed and let the old
* association to be dropped when the new one is completed.
@@ -446,7 +447,8 @@ int __cfg80211_mlme_deauth(struct cfg80211_registered_device *rdev,

if (local_state_change) {
if (wdev->current_bss &&
- memcmp(wdev->current_bss->pub.bssid, bssid, ETH_ALEN) == 0) {
+ compare_ether_addr(wdev->current_bss->pub.bssid, bssid)
+ == 0) {
cfg80211_unhold_bss(wdev->current_bss);
cfg80211_put_bss(&wdev->current_bss->pub);
wdev->current_bss = NULL;
@@ -495,7 +497,7 @@ static int __cfg80211_mlme_disassoc(struct cfg80211_registered_device *rdev,
req.local_state_change = local_state_change;
req.ie = ie;
req.ie_len = ie_len;
- if (memcmp(wdev->current_bss->pub.bssid, bssid, ETH_ALEN) == 0)
+ if (compare_ether_addr(wdev->current_bss->pub.bssid, bssid) == 0)
req.bss = &wdev->current_bss->pub;
else
return -ENOTCONN;
@@ -758,8 +760,8 @@ int cfg80211_mlme_mgmt_tx(struct cfg80211_registered_device *rdev,
break;
}

- if (memcmp(wdev->current_bss->pub.bssid,
- mgmt->bssid, ETH_ALEN)) {
+ if (compare_ether_addr(wdev->current_bss->pub.bssid,
+ mgmt->bssid)) {
err = -ENOTCONN;
break;
}
@@ -772,8 +774,8 @@ int cfg80211_mlme_mgmt_tx(struct cfg80211_registered_device *rdev,
break;

/* for station, check that DA is the AP */
- if (memcmp(wdev->current_bss->pub.bssid,
- mgmt->da, ETH_ALEN)) {
+ if (compare_ether_addr(wdev->current_bss->pub.bssid,
+ mgmt->da)) {
err = -ENOTCONN;
break;
}
@@ -781,11 +783,11 @@ int cfg80211_mlme_mgmt_tx(struct cfg80211_registered_device *rdev,
case NL80211_IFTYPE_AP:
case NL80211_IFTYPE_P2P_GO:
case NL80211_IFTYPE_AP_VLAN:
- if (memcmp(mgmt->bssid, dev->dev_addr, ETH_ALEN))
+ if (compare_ether_addr(mgmt->bssid, dev->dev_addr))
err = -EINVAL;
break;
case NL80211_IFTYPE_MESH_POINT:
- if (memcmp(mgmt->sa, mgmt->bssid, ETH_ALEN)) {
+ if (compare_ether_addr(mgmt->sa, mgmt->bssid)) {
err = -EINVAL;
break;
}
@@ -804,7 +806,7 @@ int cfg80211_mlme_mgmt_tx(struct cfg80211_registered_device *rdev,
return err;
}

- if (memcmp(mgmt->sa, dev->dev_addr, ETH_ALEN) != 0)
+ if (compare_ether_addr(mgmt->sa, dev->dev_addr) != 0)
return -EINVAL;

/* Transmit the Action frame as requested by user space */
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 70faadf..fdbcfe6 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -378,7 +378,7 @@ static int cmp_bss_core(struct cfg80211_bss *a,
b->len_information_elements);
}

- return memcmp(a->bssid, b->bssid, ETH_ALEN);
+ return compare_ether_addr(a->bssid, b->bssid);
}

static int cmp_bss(struct cfg80211_bss *a,
--
1.7.3.2



2012-03-18 21:58:18

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v2 2/3] mac80211: reduce code duplication in debugfs code

Signed-off-by: Felix Fietkau <[email protected]>
---
net/mac80211/debugfs_netdev.c | 71 +++++++---------------------------------
1 files changed, 13 insertions(+), 58 deletions(-)

diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c
index a32eeda..6ed0455 100644
--- a/net/mac80211/debugfs_netdev.c
+++ b/net/mac80211/debugfs_netdev.c
@@ -499,26 +499,23 @@ IEEE80211_IF_FILE(dot11MeshForwarding, u.mesh.mshcfg.dot11MeshForwarding, DEC);
IEEE80211_IF_FILE(rssi_threshold, u.mesh.mshcfg.rssi_threshold, DEC);
#endif

-
-#define DEBUGFS_ADD(name) \
- debugfs_create_file(#name, 0400, sdata->debugfs.dir, \
- sdata, &name##_ops);
-
#define DEBUGFS_ADD_MODE(name, mode) \
debugfs_create_file(#name, mode, sdata->debugfs.dir, \
sdata, &name##_ops);

-static void add_sta_files(struct ieee80211_sub_if_data *sdata)
+#define DEBUGFS_ADD(name) DEBUGFS_ADD_MODE(name, 0400)
+
+static void add_common_files(struct ieee80211_sub_if_data *sdata)
{
DEBUGFS_ADD(drop_unencrypted);
- DEBUGFS_ADD(flags);
- DEBUGFS_ADD(state);
- DEBUGFS_ADD(channel_type);
DEBUGFS_ADD(rc_rateidx_mask_2ghz);
DEBUGFS_ADD(rc_rateidx_mask_5ghz);
DEBUGFS_ADD(rc_rateidx_mcs_mask_2ghz);
DEBUGFS_ADD(rc_rateidx_mcs_mask_5ghz);
+}

+static void add_sta_files(struct ieee80211_sub_if_data *sdata)
+{
DEBUGFS_ADD(bssid);
DEBUGFS_ADD(aid);
DEBUGFS_ADD(last_beacon);
@@ -531,15 +528,6 @@ static void add_sta_files(struct ieee80211_sub_if_data *sdata)

static void add_ap_files(struct ieee80211_sub_if_data *sdata)
{
- DEBUGFS_ADD(drop_unencrypted);
- DEBUGFS_ADD(flags);
- DEBUGFS_ADD(state);
- DEBUGFS_ADD(channel_type);
- DEBUGFS_ADD(rc_rateidx_mask_2ghz);
- DEBUGFS_ADD(rc_rateidx_mask_5ghz);
- DEBUGFS_ADD(rc_rateidx_mcs_mask_2ghz);
- DEBUGFS_ADD(rc_rateidx_mcs_mask_5ghz);
-
DEBUGFS_ADD(num_sta_authorized);
DEBUGFS_ADD(num_sta_ps);
DEBUGFS_ADD(dtim_count);
@@ -549,48 +537,14 @@ static void add_ap_files(struct ieee80211_sub_if_data *sdata)

static void add_ibss_files(struct ieee80211_sub_if_data *sdata)
{
- DEBUGFS_ADD(channel_type);
- DEBUGFS_ADD(rc_rateidx_mask_2ghz);
- DEBUGFS_ADD(rc_rateidx_mask_5ghz);
- DEBUGFS_ADD(rc_rateidx_mcs_mask_2ghz);
- DEBUGFS_ADD(rc_rateidx_mcs_mask_5ghz);
-
DEBUGFS_ADD_MODE(tsf, 0600);
}

static void add_wds_files(struct ieee80211_sub_if_data *sdata)
{
- DEBUGFS_ADD(drop_unencrypted);
- DEBUGFS_ADD(flags);
- DEBUGFS_ADD(state);
- DEBUGFS_ADD(channel_type);
- DEBUGFS_ADD(rc_rateidx_mask_2ghz);
- DEBUGFS_ADD(rc_rateidx_mask_5ghz);
- DEBUGFS_ADD(rc_rateidx_mcs_mask_2ghz);
- DEBUGFS_ADD(rc_rateidx_mcs_mask_5ghz);
-
DEBUGFS_ADD(peer);
}

-static void add_vlan_files(struct ieee80211_sub_if_data *sdata)
-{
- DEBUGFS_ADD(drop_unencrypted);
- DEBUGFS_ADD(flags);
- DEBUGFS_ADD(state);
- DEBUGFS_ADD(channel_type);
- DEBUGFS_ADD(rc_rateidx_mask_2ghz);
- DEBUGFS_ADD(rc_rateidx_mask_5ghz);
- DEBUGFS_ADD(rc_rateidx_mcs_mask_2ghz);
- DEBUGFS_ADD(rc_rateidx_mcs_mask_5ghz);
-}
-
-static void add_monitor_files(struct ieee80211_sub_if_data *sdata)
-{
- DEBUGFS_ADD(flags);
- DEBUGFS_ADD(state);
- DEBUGFS_ADD(channel_type);
-}
-
#ifdef CONFIG_MAC80211_MESH

static void add_mesh_files(struct ieee80211_sub_if_data *sdata)
@@ -651,6 +605,13 @@ static void add_files(struct ieee80211_sub_if_data *sdata)
if (!sdata->debugfs.dir)
return;

+ DEBUGFS_ADD(flags);
+ DEBUGFS_ADD(state);
+ DEBUGFS_ADD(channel_type);
+
+ if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
+ add_common_files(sdata);
+
switch (sdata->vif.type) {
case NL80211_IFTYPE_MESH_POINT:
#ifdef CONFIG_MAC80211_MESH
@@ -671,12 +632,6 @@ static void add_files(struct ieee80211_sub_if_data *sdata)
case NL80211_IFTYPE_WDS:
add_wds_files(sdata);
break;
- case NL80211_IFTYPE_MONITOR:
- add_monitor_files(sdata);
- break;
- case NL80211_IFTYPE_AP_VLAN:
- add_vlan_files(sdata);
- break;
default:
break;
}
--
1.7.3.2


2012-03-18 21:58:20

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v2 3/3] mac80211: optimize aggregation session timeout handling

Calling mod_timer from the rx/tx hotpath is somewhat expensive, and the
timeout doesn't need to be so precise.

Switch to a different strategy: Schedule the timer initially, store jiffies
of all last rx/tx activity which would previously modify the timer, and
let the timer re-arm itself after checking the last rx/tx timestamp.
Make the session timers deferrable to avoid causing extra wakeups on systems
running on battery.
This visibly reduces CPU load under high network load on small embedded
systems.

Signed-off-by: Felix Fietkau <[email protected]>
---
net/mac80211/agg-rx.c | 18 ++++++++++++++++--
net/mac80211/agg-tx.c | 18 ++++++++++++++++--
net/mac80211/ieee80211_i.h | 3 ++-
net/mac80211/rx.c | 3 +--
net/mac80211/sta_info.h | 4 ++++
net/mac80211/tx.c | 3 +--
6 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
index 1068f66..9de183f 100644
--- a/net/mac80211/agg-rx.c
+++ b/net/mac80211/agg-rx.c
@@ -141,6 +141,18 @@ static void sta_rx_agg_session_timer_expired(unsigned long data)
u8 *timer_to_id = ptid - *ptid;
struct sta_info *sta = container_of(timer_to_id, struct sta_info,
timer_to_tid[0]);
+ struct tid_ampdu_rx *tid_rx;
+ unsigned long timeout;
+
+ tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]);
+ if (!tid_rx)
+ return;
+
+ timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
+ if (time_is_after_jiffies(timeout)) {
+ mod_timer(&tid_rx->session_timer, timeout);
+ return;
+ }

#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
@@ -290,7 +302,7 @@ void ieee80211_process_addba_request(struct ieee80211_local *local,
/* rx timer */
tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
- init_timer(&tid_agg_rx->session_timer);
+ init_timer_deferrable(&tid_agg_rx->session_timer);

/* rx reorder timer */
tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
@@ -334,8 +346,10 @@ void ieee80211_process_addba_request(struct ieee80211_local *local,
/* activate it for RX */
rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);

- if (timeout)
+ if (timeout) {
mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
+ tid_agg_rx->last_rx = jiffies;
+ }

end:
mutex_unlock(&sta->ampdu_mlme.mtx);
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index 76be617..9628a18 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -417,6 +417,18 @@ static void sta_tx_agg_session_timer_expired(unsigned long data)
u8 *timer_to_id = ptid - *ptid;
struct sta_info *sta = container_of(timer_to_id, struct sta_info,
timer_to_tid[0]);
+ struct tid_ampdu_tx *tid_tx;
+ unsigned long timeout;
+
+ tid_tx = rcu_dereference_protected_tid_tx(sta, *ptid);
+ if (!tid_tx)
+ return;
+
+ timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout);
+ if (time_is_after_jiffies(timeout)) {
+ mod_timer(&tid_tx->session_timer, timeout);
+ return;
+ }

#ifdef CONFIG_MAC80211_HT_DEBUG
printk(KERN_DEBUG "tx session timer expired on tid %d\n", (u16)*ptid);
@@ -542,7 +554,7 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
/* tx timer */
tid_tx->session_timer.function = sta_tx_agg_session_timer_expired;
tid_tx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
- init_timer(&tid_tx->session_timer);
+ init_timer_deferrable(&tid_tx->session_timer);

/* assign a dialog token */
sta->ampdu_mlme.dialog_token_allocator++;
@@ -884,9 +896,11 @@ void ieee80211_process_addba_resp(struct ieee80211_local *local,

sta->ampdu_mlme.addba_req_num[tid] = 0;

- if (tid_tx->timeout)
+ if (tid_tx->timeout) {
mod_timer(&tid_tx->session_timer,
TU_TO_EXP_TIME(tid_tx->timeout));
+ tid_tx->last_tx = jiffies;
+ }

} else {
___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR,
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index d9798a3..2785976 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -52,7 +52,8 @@ struct ieee80211_local;
* increased memory use (about 2 kB of RAM per entry). */
#define IEEE80211_FRAGMENT_MAX 4

-#define TU_TO_EXP_TIME(x) (jiffies + usecs_to_jiffies((x) * 1024))
+#define TU_TO_JIFFIES(x) (usecs_to_jiffies((x) * 1024))
+#define TU_TO_EXP_TIME(x) (jiffies + TU_TO_JIFFIES(x))

#define IEEE80211_DEFAULT_UAPSD_QUEUES \
(IEEE80211_WMM_IE_STA_QOSINFO_AC_BK | \
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index bcfe8c7..8da3b36 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -793,8 +793,7 @@ static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx)

/* reset session timer */
if (tid_agg_rx->timeout)
- mod_timer(&tid_agg_rx->session_timer,
- TU_TO_EXP_TIME(tid_agg_rx->timeout));
+ tid_agg_rx->last_rx = jiffies;

/* if this mpdu is fragmented - terminate rx aggregation session */
sc = le16_to_cpu(hdr->seq_ctrl);
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index ab05768..e21652b 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -101,6 +101,7 @@ enum ieee80211_sta_info_flags {
* @dialog_token: dialog token for aggregation session
* @timeout: session timeout value to be filled in ADDBA requests
* @state: session state (see above)
+ * @last_tx: jiffies of last tx activity
* @stop_initiator: initiator of a session stop
* @tx_stop: TX DelBA frame when stopping
* @buf_size: reorder buffer size at receiver
@@ -122,6 +123,7 @@ struct tid_ampdu_tx {
struct timer_list addba_resp_timer;
struct sk_buff_head pending;
unsigned long state;
+ unsigned long last_tx;
u16 timeout;
u8 dialog_token;
u8 stop_initiator;
@@ -139,6 +141,7 @@ struct tid_ampdu_tx {
* @reorder_time: jiffies when skb was added
* @session_timer: check if peer keeps Tx-ing on the TID (by timeout value)
* @reorder_timer: releases expired frames from the reorder buffer.
+ * @last_rx: jiffies of last rx activity
* @head_seq_num: head sequence number in reordering buffer.
* @stored_mpdu_num: number of MPDUs in reordering buffer
* @ssn: Starting Sequence Number expected to be aggregated.
@@ -163,6 +166,7 @@ struct tid_ampdu_rx {
unsigned long *reorder_time;
struct timer_list session_timer;
struct timer_list reorder_timer;
+ unsigned long last_rx;
u16 head_seq_num;
u16 stored_mpdu_num;
u16 ssn;
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 782a601..5ad2c40 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1118,8 +1118,7 @@ static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,

/* reset session timer */
if (reset_agg_timer && tid_tx->timeout)
- mod_timer(&tid_tx->session_timer,
- TU_TO_EXP_TIME(tid_tx->timeout));
+ tid_tx->last_tx = jiffies;

return queued;
}
--
1.7.3.2