Convert xen driver to 64 bit statistics interface.
Use stats_sync to ensure that 64 bit update is read atomically
on 32 bit platform. Put hot statistics into per-cpu table.
Signed-off-by: Stephen Hemminger <shemminger@xxxxxxxxxx>
---
v2 - add stats_sync and per-cpu
--- a/drivers/net/xen-netfront.c 2011-06-20 13:34:56.383992463 -0700
+++ b/drivers/net/xen-netfront.c 2011-06-20 13:41:47.207992232 -0700
@@ -70,6 +70,14 @@ struct netfront_cb {
#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
#define TX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
+struct netfront_stats {
+ u64 rx_packets;
+ u64 tx_packets;
+ u64 rx_bytes;
+ u64 tx_bytes;
+ struct u64_stats_sync syncp;
+};
+
struct netfront_info {
struct list_head list;
struct net_device *netdev;
@@ -122,6 +130,8 @@ struct netfront_info {
struct mmu_update rx_mmu[NET_RX_RING_SIZE];
/* Statistics */
+ struct netfront_stats __percpu *stats;
+
unsigned long rx_gso_checksum_fixup;
};
@@ -468,6 +478,7 @@ static int xennet_start_xmit(struct sk_b
{
unsigned short id;
struct netfront_info *np = netdev_priv(dev);
+ struct netfront_stats *stats = this_cpu_ptr(np->stats);
struct xen_netif_tx_request *tx;
struct xen_netif_extra_info *extra;
char *data = skb->data;
@@ -552,8 +563,10 @@ static int xennet_start_xmit(struct sk_b
if (notify)
notify_remote_via_irq(np->netdev->irq);
- dev->stats.tx_bytes += skb->len;
- dev->stats.tx_packets++;
+ u64_stats_update_begin(&stats->syncp);
+ stats->tx_bytes += skb->len;
+ stats->tx_packets++;
+ u64_stats_update_end(&stats->syncp);
/* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
xennet_tx_buf_gc(dev);
@@ -847,6 +860,8 @@ out:
static int handle_incoming_queue(struct net_device *dev,
struct sk_buff_head *rxq)
{
+ struct netfront_info *np = netdev_priv(dev);
+ struct netfront_stats *stats = this_cpu_ptr(np->stats);
int packets_dropped = 0;
struct sk_buff *skb;
@@ -867,12 +882,13 @@ static int handle_incoming_queue(struct
if (checksum_setup(dev, skb)) {
kfree_skb(skb);
packets_dropped++;
- dev->stats.rx_errors++;
continue;
}
- dev->stats.rx_packets++;
- dev->stats.rx_bytes += skb->len;
+ u64_stats_update_begin(&stats->syncp);
+ stats->rx_packets++;
+ stats->rx_bytes += skb->len;
+ u64_stats_update_end(&stats->syncp);
/* Pass it up. */
netif_receive_skb(skb);
@@ -1034,6 +1050,38 @@ static int xennet_change_mtu(struct net_
return 0;
}
+static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
+ struct rtnl_link_stats64
*tot)
+{
+ struct netfront_info *np = netdev_priv(dev);
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu);
+ u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
+ unsigned int start;
+
+ do {
+ start = u64_stats_fetch_begin_bh(&stats->syncp);
+
+ rx_packets = stats->rx_packets;
+ tx_packets = stats->tx_packets;
+ rx_bytes = stats->rx_bytes;
+ tx_bytes = stats->tx_bytes;
+ } while (u64_stats_fetch_retry_bh(&stats->syncp, start));
+
+ tot->rx_packets += rx_packets;
+ tot->tx_packets += tx_packets;
+ tot->rx_bytes += rx_bytes;
+ tot->tx_bytes += tx_bytes;
+ }
+
+ tot->rx_errors = dev->stats.rx_errors;
+ tot->tx_dropped = dev->stats.tx_dropped;
+
+ return tot;
+}
+
static void xennet_release_tx_bufs(struct netfront_info *np)
{
struct sk_buff *skb;
@@ -1182,6 +1230,7 @@ static const struct net_device_ops xenne
.ndo_stop = xennet_close,
.ndo_start_xmit = xennet_start_xmit,
.ndo_change_mtu = xennet_change_mtu,
+ .ndo_get_stats64 = xennet_get_stats64,
.ndo_set_mac_address = eth_mac_addr,
.ndo_validate_addr = eth_validate_addr,
.ndo_fix_features = xennet_fix_features,
@@ -1216,6 +1265,11 @@ static struct net_device * __devinit xen
np->rx_refill_timer.data = (unsigned long)netdev;
np->rx_refill_timer.function = rx_refill_timeout;
+ err = -ENOMEM;
+ np->stats = alloc_percpu(struct netfront_stats);
+ if (np->stats == NULL)
+ goto exit;
+
/* Initialise tx_skbs as a free chain containing every entry. */
np->tx_skb_freelist = 0;
for (i = 0; i < NET_TX_RING_SIZE; i++) {
@@ -1234,7 +1288,7 @@ static struct net_device * __devinit xen
&np->gref_tx_head) < 0) {
printk(KERN_ALERT "#### netfront can't alloc tx grant refs\n");
err = -ENOMEM;
- goto exit;
+ goto exit_free_stats;
}
/* A grant for every rx ring slot */
if (gnttab_alloc_grant_references(RX_MAX_TARGET,
@@ -1270,6 +1324,8 @@ static struct net_device * __devinit xen
exit_free_tx:
gnttab_free_grant_references(np->gref_tx_head);
+ exit_free_stats:
+ free_percpu(np->stats);
exit:
free_netdev(netdev);
return ERR_PTR(err);
@@ -1869,6 +1925,8 @@ static int __devexit xennet_remove(struc
xennet_sysfs_delif(info->netdev);
+ free_percpu(info->stats);
+
free_netdev(info->netdev);
return 0;
>From shemminger@xxxxxxxxxx Mon Jun 20 13:36:03 2011
Message-Id: <20110620203603.019928129@xxxxxxxxxx>
User-Agent: quilt/0.48-1
Date: Mon, 20 Jun 2011 13:35:11 -0700
From: Stephen Hemminger <shemminger@xxxxxxxxxx>
To: davem@xxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Subject: [PATCH net-next 5/5] ifb: convert to 64 bit stats
References: <20110620203506.363818794@xxxxxxxxxx>
Content-Disposition: inline; filename=ifb-stats64.patch
Convert input functional block device to use 64 bit stats.
Signed-off-by: Stephen Hemminger <shemminger@xxxxxxxxxx>
---
v2 - add stats_sync
--- a/drivers/net/ifb.c 2011-06-09 14:39:25.000000000 -0700
+++ b/drivers/net/ifb.c 2011-06-20 13:30:30.135992612 -0700
@@ -41,8 +41,18 @@
struct ifb_private {
struct tasklet_struct ifb_tasklet;
int tasklet_pending;
+
struct sk_buff_head rq;
+ u64 rx_packets;
+ u64 rx_bytes;
+ unsigned long rx_dropped;
+
struct sk_buff_head tq;
+ u64 tx_packets;
+ u64 tx_bytes;
+ unsigned long tx_dropped;
+
+ struct u64_stats_sync stats_sync;
};
static int numifbs = 2;
@@ -57,7 +67,6 @@ static void ri_tasklet(unsigned long dev
struct net_device *_dev = (struct net_device *)dev;
struct ifb_private *dp = netdev_priv(_dev);
- struct net_device_stats *stats = &_dev->stats;
struct netdev_queue *txq;
struct sk_buff *skb;
@@ -77,15 +86,18 @@ static void ri_tasklet(unsigned long dev
skb->tc_verd = 0;
skb->tc_verd = SET_TC_NCLS(skb->tc_verd);
- stats->tx_packets++;
- stats->tx_bytes +=skb->len;
+
+ u64_stats_update_begin(&dp->stats_sync);
+ dp->tx_packets++;
+ dp->tx_bytes += skb->len;
+ u64_stats_update_end(&dp->stats_sync);
rcu_read_lock();
skb->dev = dev_get_by_index_rcu(&init_net, skb->skb_iif);
if (!skb->dev) {
rcu_read_unlock();
dev_kfree_skb(skb);
- stats->tx_dropped++;
+ dp->tx_dropped++;
if (skb_queue_len(&dp->tq) != 0)
goto resched;
break;
@@ -120,9 +132,33 @@ resched:
}
+static struct rtnl_link_stats64 *ifb_stats64(struct net_device *dev,
+ struct rtnl_link_stats64 *stats)
+{
+ struct ifb_private *dp = netdev_priv(dev);
+ unsigned int start;
+
+ do {
+ start = u64_stats_fetch_begin_bh(&dp->stats_sync);
+
+ stats->rx_packets = dp->rx_packets;
+ stats->rx_bytes = dp->rx_bytes;
+ stats->tx_packets = dp->tx_packets;
+ stats->tx_bytes = dp->tx_bytes;
+
+ } while (u64_stats_fetch_retry_bh(&dp->stats_sync, start));
+
+ stats->rx_dropped = dp->rx_dropped;
+ stats->tx_dropped = dp->tx_dropped;
+
+ return stats;
+}
+
+
static const struct net_device_ops ifb_netdev_ops = {
.ndo_open = ifb_open,
.ndo_stop = ifb_close,
+ .ndo_get_stats64 = ifb_stats64,
.ndo_start_xmit = ifb_xmit,
.ndo_validate_addr = eth_validate_addr,
};
@@ -153,15 +189,16 @@ static void ifb_setup(struct net_device
static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ifb_private *dp = netdev_priv(dev);
- struct net_device_stats *stats = &dev->stats;
u32 from = G_TC_FROM(skb->tc_verd);
- stats->rx_packets++;
- stats->rx_bytes+=skb->len;
+ u64_stats_update_begin(&dp->stats_sync);
+ dp->rx_packets++;
+ dp->rx_bytes += skb->len;
+ u64_stats_update_end(&dp->stats_sync);
if (!(from & (AT_INGRESS|AT_EGRESS)) || !skb->skb_iif) {
dev_kfree_skb(skb);
- stats->rx_dropped++;
+ dp->rx_dropped++;
return NETDEV_TX_OK;
}
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