net: remove dev->trans_start

previous patches removed all direct accesses to dev->trans_start,
so change the netif_trans_update helper to update trans_start of
netdev queue 0 instead and then remove trans_start from struct net_device.

AFAICS a lot of the netif_trans_update() invocations are now useless
because they occur in ndo_start_xmit and driver doesn't set LLTX
(i.e. stack already took care of the update).

As I can't test any of them it seems better to just leave them alone.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 8e6c0f2..f6da6b7 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -328,7 +328,7 @@ static void i40e_tx_timeout(struct net_device *netdev)
                unsigned long trans_start;
 
                q = netdev_get_tx_queue(netdev, i);
-               trans_start = q->trans_start ? : netdev->trans_start;
+               trans_start = q->trans_start;
                if (netif_xmit_stopped(q) &&
                    time_after(jiffies,
                               (trans_start + netdev->watchdog_timeo))) {

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index f53412c..63580e6 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -581,7 +581,7 @@ struct netdev_queue {
        spinlock_t              _xmit_lock ____cacheline_aligned_in_smp;
        int                     xmit_lock_owner;
        /*
-        * please use this field instead of dev->trans_start
+        * Time (in jiffies) of last Tx
         */
        unsigned long           trans_start;
 
@@ -1545,7 +1545,6 @@ enum netdev_priv_flags {
  *
  *     @offload_fwd_mark:      Offload device fwding mark
  *
- *     @trans_start:           Time (in jiffies) of last Tx
  *     @watchdog_timeo:        Represents the timeout that is used by
  *                             the watchdog (see dev_watchdog())
  *     @watchdog_timer:        List of timers
@@ -1794,13 +1793,6 @@ struct net_device {
 #endif
 
        /* These may be needed for future network-power-down code. */
-
-       /*
-        * trans_start here is expensive for high speed devices on SMP,
-        * please use netdev_queue->trans_start instead.
-        */
-       unsigned long           trans_start;
-
        struct timer_list       watchdog_timer;
 
        int __percpu            *pcpu_refcnt;
@@ -3484,7 +3476,10 @@ static inline void txq_trans_update(struct netdev_queue *txq)
 /* legacy drivers only, netdev_start_xmit() sets txq->trans_start */
 static inline void netif_trans_update(struct net_device *dev)
 {
-       dev->trans_start = jiffies;
+       struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
+
+       if (txq->trans_start != jiffies)
+               txq->trans_start = jiffies;
 }
 
 /**

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 70182cf..269dd71 100644 (file)
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -227,13 +227,12 @@ unsigned long dev_trans_start(struct net_device *dev)
 
        if (is_vlan_dev(dev))
                dev = vlan_dev_real_dev(dev);
-       res = dev->trans_start;
-       for (i = 0; i < dev->num_tx_queues; i++) {
+       res = netdev_get_tx_queue(dev, 0)->trans_start;
+       for (i = 1; i < dev->num_tx_queues; i++) {
                val = netdev_get_tx_queue(dev, i)->trans_start;
                if (val && time_after(val, res))
                        res = val;
        }
-       dev->trans_start = res;
 
        return res;
 }
@@ -256,10 +255,7 @@ static void dev_watchdog(unsigned long arg)
                                struct netdev_queue *txq;
 
                                txq = netdev_get_tx_queue(dev, i);
-                               /*
-                                * old device drivers set dev->trans_start
-                                */
-                               trans_start = txq->trans_start ? : dev->trans_start;
+                               trans_start = txq->trans_start;
                                if (netif_xmit_stopped(txq) &&
                                    time_after(jiffies, (trans_start +
                                                         dev->watchdog_timeo))) {