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| author | Eric Dumazet <dada1@cosmosbay.com> | 2006-10-18 20:51:57 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2006-10-18 20:51:57 -0700 |
| commit | 5175c3786c244f8b689854db24c9e79b1c6a084f (patch) | |
| tree | 459975fe6a7b6dd5294b362397b185959b4ab96d /drivers/net/loopback.c | |
| parent | 9ce8ade015a3f82dbdf856df7a685878dd1cc0e1 (diff) | |
| download | linux-5175c3786c244f8b689854db24c9e79b1c6a084f.tar.gz linux-5175c3786c244f8b689854db24c9e79b1c6a084f.tar.bz2 linux-5175c3786c244f8b689854db24c9e79b1c6a084f.zip | |
[NET]: reduce per cpu ram used for loopback stats
We dont need a full struct net_device_stats (currently 23 long : 184 bytes on
x86_64) per possible CPU, but only two counters : bytes and packets
We save few CPU cycles too in loopback_xmit() not updating 4 fields, but 2.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/loopback.c')
| -rw-r--r-- | drivers/net/loopback.c | 35 |
1 files changed, 19 insertions, 16 deletions
diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c index 4178b4b1d2df..93fbea1c9271 100644 --- a/drivers/net/loopback.c +++ b/drivers/net/loopback.c @@ -58,7 +58,11 @@ #include <linux/tcp.h> #include <linux/percpu.h> -static DEFINE_PER_CPU(struct net_device_stats, loopback_stats); +struct pcpu_lstats { + unsigned long packets; + unsigned long bytes; +}; +static DEFINE_PER_CPU(struct pcpu_lstats, pcpu_lstats); #define LOOPBACK_OVERHEAD (128 + MAX_HEADER + 16 + 16) @@ -128,7 +132,7 @@ static void emulate_large_send_offload(struct sk_buff *skb) */ static int loopback_xmit(struct sk_buff *skb, struct net_device *dev) { - struct net_device_stats *lb_stats; + struct pcpu_lstats *lb_stats; skb_orphan(skb); @@ -149,11 +153,9 @@ static int loopback_xmit(struct sk_buff *skb, struct net_device *dev) #endif dev->last_rx = jiffies; - lb_stats = &per_cpu(loopback_stats, get_cpu()); - lb_stats->rx_bytes += skb->len; - lb_stats->tx_bytes = lb_stats->rx_bytes; - lb_stats->rx_packets++; - lb_stats->tx_packets = lb_stats->rx_packets; + lb_stats = &per_cpu(pcpu_lstats, get_cpu()); + lb_stats->bytes += skb->len; + lb_stats->packets++; put_cpu(); netif_rx(skb); @@ -166,20 +168,21 @@ static struct net_device_stats loopback_stats; static struct net_device_stats *get_stats(struct net_device *dev) { struct net_device_stats *stats = &loopback_stats; + unsigned long bytes = 0; + unsigned long packets = 0; int i; - memset(stats, 0, sizeof(struct net_device_stats)); - for_each_possible_cpu(i) { - struct net_device_stats *lb_stats; + const struct pcpu_lstats *lb_stats; - lb_stats = &per_cpu(loopback_stats, i); - stats->rx_bytes += lb_stats->rx_bytes; - stats->tx_bytes += lb_stats->tx_bytes; - stats->rx_packets += lb_stats->rx_packets; - stats->tx_packets += lb_stats->tx_packets; + lb_stats = &per_cpu(pcpu_lstats, i); + bytes += lb_stats->bytes; + packets += lb_stats->packets; } - + stats->rx_packets = packets; + stats->tx_packets = packets; + stats->rx_bytes = bytes; + stats->tx_bytes = bytes; return stats; } |