[Make-wifi-fast] [PATCHv5 3/5] mac80211: add debug knobs for fair queuing
Michal Kazior
michal.kazior at tieto.com
Thu May 19 04:37:50 EDT 2016
This adds a debugfs entry to read and modify some
fq parameters and inroduces a module parameter to
control number of flows mac80211 shuold maintain.
This makes it easy to debug, test and experiment.
Signed-off-by: Michal Kazior <michal.kazior at tieto.com>
---
Notes:
v5:
* expose a single "aqm" debugfs knob to maintain
coherent stat values [Dave]
net/mac80211/debugfs.c | 173 +++++++++++++++++++++++++++++++++++++++++++++++++
net/mac80211/tx.c | 8 ++-
2 files changed, 180 insertions(+), 1 deletion(-)
diff --git a/net/mac80211/debugfs.c b/net/mac80211/debugfs.c
index b251b2f7f8dd..2906c1004e1a 100644
--- a/net/mac80211/debugfs.c
+++ b/net/mac80211/debugfs.c
@@ -10,6 +10,7 @@
#include <linux/debugfs.h>
#include <linux/rtnetlink.h>
+#include <linux/vmalloc.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
#include "rate.h"
@@ -70,6 +71,177 @@ DEBUGFS_READONLY_FILE(wep_iv, "%#08x",
DEBUGFS_READONLY_FILE(rate_ctrl_alg, "%s",
local->rate_ctrl ? local->rate_ctrl->ops->name : "hw/driver");
+struct aqm_info {
+ struct ieee80211_local *local;
+ size_t size;
+ size_t len;
+ unsigned char buf[0];
+};
+
+#define AQM_HDR_LEN 200
+#define AQM_HW_ENTRY_LEN 40
+#define AQM_TXQ_ENTRY_LEN 110
+
+static int aqm_open(struct inode *inode, struct file *file)
+{
+ struct ieee80211_local *local = inode->i_private;
+ struct ieee80211_sub_if_data *sdata;
+ struct sta_info *sta;
+ struct txq_info *txqi;
+ struct fq *fq = &local->fq;
+ struct aqm_info *info = NULL;
+ int len = 0;
+ int i;
+
+ if (!local->ops->wake_tx_queue)
+ return -EOPNOTSUPP;
+
+ len += AQM_HDR_LEN;
+ len += 6 * AQM_HW_ENTRY_LEN;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(sdata, &local->interfaces, list)
+ len += AQM_TXQ_ENTRY_LEN;
+ list_for_each_entry_rcu(sta, &local->sta_list, list)
+ len += AQM_TXQ_ENTRY_LEN * ARRAY_SIZE(sta->sta.txq);
+ rcu_read_unlock();
+
+ info = vmalloc(len);
+ if (!info)
+ return -ENOMEM;
+
+ spin_lock_bh(&local->fq.lock);
+ rcu_read_lock();
+
+ file->private_data = info;
+ info->local = local;
+ info->size = len;
+ len = 0;
+
+ len += scnprintf(info->buf + len, info->size - len,
+ "* hw\n"
+ "access name value\n"
+ "R fq_flows_cnt %u\n"
+ "R fq_backlog %u\n"
+ "R fq_overlimit %u\n"
+ "R fq_collisions %u\n"
+ "RW fq_limit %u\n"
+ "RW fq_quantum %u\n",
+ fq->flows_cnt,
+ fq->backlog,
+ fq->overlimit,
+ fq->collisions,
+ fq->limit,
+ fq->quantum);
+
+ len += scnprintf(info->buf + len,
+ info->size - len,
+ "* vif\n"
+ "ifname addr ac backlog-bytes backlog-packets flows overlimit collisions tx-bytes tx-packets\n");
+
+ list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+ txqi = to_txq_info(sdata->vif.txq);
+ len += scnprintf(info->buf + len, info->size - len,
+ "%s %pM %u %u %u %u %u %u %u %u\n",
+ sdata->name,
+ sdata->vif.addr,
+ txqi->txq.ac,
+ txqi->tin.backlog_bytes,
+ txqi->tin.backlog_packets,
+ txqi->tin.flows,
+ txqi->tin.overlimit,
+ txqi->tin.collisions,
+ txqi->tin.tx_bytes,
+ txqi->tin.tx_packets);
+ }
+
+ len += scnprintf(info->buf + len,
+ info->size - len,
+ "* sta\n"
+ "ifname addr tid ac backlog-bytes backlog-packets flows overlimit collisions tx-bytes tx-packets\n");
+
+ list_for_each_entry_rcu(sta, &local->sta_list, list) {
+ sdata = sta->sdata;
+ for (i = 0; i < ARRAY_SIZE(sta->sta.txq); i++) {
+ txqi = to_txq_info(sta->sta.txq[i]);
+ len += scnprintf(info->buf + len, info->size - len,
+ "%s %pM %d %d %u %u %u %u %u %u %u\n",
+ sdata->name,
+ sta->sta.addr,
+ txqi->txq.tid,
+ txqi->txq.ac,
+ txqi->tin.backlog_bytes,
+ txqi->tin.backlog_packets,
+ txqi->tin.flows,
+ txqi->tin.overlimit,
+ txqi->tin.collisions,
+ txqi->tin.tx_bytes,
+ txqi->tin.tx_packets);
+ }
+ }
+
+ info->len = len;
+
+ rcu_read_unlock();
+ spin_unlock_bh(&local->fq.lock);
+
+ return 0;
+}
+
+static int aqm_release(struct inode *inode, struct file *file)
+{
+ vfree(file->private_data);
+ return 0;
+}
+
+static ssize_t aqm_read(struct file *file,
+ char __user *user_buf,
+ size_t count,
+ loff_t *ppos)
+{
+ struct aqm_info *info = file->private_data;
+
+ return simple_read_from_buffer(user_buf, count, ppos,
+ info->buf, info->len);
+}
+
+static ssize_t aqm_write(struct file *file,
+ const char __user *user_buf,
+ size_t count,
+ loff_t *ppos)
+{
+ struct aqm_info *info = file->private_data;
+ struct ieee80211_local *local = info->local;
+ char buf[100];
+ size_t len;
+
+ if (count > sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(buf, user_buf, count))
+ return -EFAULT;
+
+ buf[sizeof(buf) - 1] = '\0';
+ len = strlen(buf);
+ if (len > 0 && buf[len-1] == '\n')
+ buf[len-1] = 0;
+
+ if (sscanf(buf, "fq_limit %u", &local->fq.limit) == 1)
+ return count;
+ else if (sscanf(buf, "fq_quantum %u", &local->fq.quantum) == 1)
+ return count;
+
+ return -EINVAL;
+}
+
+static const struct file_operations aqm_ops = {
+ .write = aqm_write,
+ .read = aqm_read,
+ .open = aqm_open,
+ .release = aqm_release,
+ .llseek = default_llseek,
+};
+
#ifdef CONFIG_PM
static ssize_t reset_write(struct file *file, const char __user *user_buf,
size_t count, loff_t *ppos)
@@ -256,6 +428,7 @@ void debugfs_hw_add(struct ieee80211_local *local)
DEBUGFS_ADD(hwflags);
DEBUGFS_ADD(user_power);
DEBUGFS_ADD(power);
+ DEBUGFS_ADD_MODE(aqm, 0600);
statsd = debugfs_create_dir("statistics", phyd);
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 1d8343fca6d4..2b60b10e6990 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -17,6 +17,7 @@
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
+#include <linux/moduleparam.h>
#include <linux/bitmap.h>
#include <linux/rcupdate.h>
#include <linux/export.h>
@@ -36,6 +37,11 @@
#include "wme.h"
#include "rate.h"
+static unsigned int fq_flows_cnt = 4096;
+module_param(fq_flows_cnt, uint, 0644);
+MODULE_PARM_DESC(fq_flows_cnt,
+ "Maximum number of txq fair queuing flows. ");
+
/* misc utils */
static inline void ieee80211_tx_stats(struct net_device *dev, u32 len)
@@ -1346,7 +1352,7 @@ int ieee80211_txq_setup_flows(struct ieee80211_local *local)
if (!local->ops->wake_tx_queue)
return 0;
- ret = fq_init(fq, 4096);
+ ret = fq_init(fq, max_t(u32, fq_flows_cnt, 1));
if (ret)
return ret;
--
2.1.4
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