Re: [PATCH v2] slip: Use net_device_stats from struct net_device

Eric Dumazet
2010-08-26T08:39:37Z

Le jeudi 26 août 2010 à 10:28 +0200, Tobias Klauser a écrit :
> Use net_device->stats for stats instead of private variable copies in
> struct slip.
>
> Cc: Eric Dumazet <eric.dumazet@gmail.com>
> Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
> ---
> drivers/net/slip.c | 47 ++++++++++++++++++++---------------------------
> drivers/net/slip.h | 9 ---------
> 2 files changed, 20 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/net/slip.c b/drivers/net/slip.c
> index d5a36f5..9512da8 100644
> --- a/drivers/net/slip.c
> +++ b/drivers/net/slip.c
> @@ -271,7 +271,7 @@ static int sl_realloc_bufs(struct slip *sl, int mtu)
> memcpy(sl->xbuff, sl->xhead, sl->xleft);
> } else {
> sl->xleft = 0;
> - sl->tx_dropped++;
> + dev->stats.tx_dropped++;
> }
> }
> sl->xhead = sl->xbuff;
> @@ -281,7 +281,7 @@ static int sl_realloc_bufs(struct slip *sl, int mtu)
> memcpy(sl->rbuff, rbuff, sl->rcount);
> } else {
> sl->rcount = 0;
> - sl->rx_over_errors++;
> + dev->stats.rx_over_errors++;
> set_bit(SLF_ERROR, &sl->flags);
> }
> }
> @@ -319,6 +319,7 @@ static inline void sl_unlock(struct slip *sl)
> /* Send one completely decapsulated IP datagram to the IP layer. */
> static void sl_bump(struct slip *sl)
> {
> + struct net_device *dev = sl->dev;
> struct sk_buff *skb;
> int count;
>
> @@ -329,13 +330,13 @@ static void sl_bump(struct slip *sl)
> if (c & SL_TYPE_COMPRESSED_TCP) {
> /* ignore compressed packets when CSLIP is off */
> if (!(sl->mode & SL_MODE_CSLIP)) {
> - printk(KERN_WARNING "%s: compressed packet ignored\n", sl->dev->name);
> + printk(KERN_WARNING "%s: compressed packet ignored\n", dev->name);
> return;
> }
> /* make sure we've reserved enough space for uncompress
> to use */
> if (count + 80 > sl->buffsize) {
> - sl->rx_over_errors++;
> + dev->stats.rx_over_errors++;
> return;
> }
> count = slhc_uncompress(sl->slcomp, sl->rbuff, count);
> @@ -346,7 +347,7 @@ static void sl_bump(struct slip *sl)
> /* turn on header compression */
> sl->mode |= SL_MODE_CSLIP;
> sl->mode &= ~SL_MODE_ADAPTIVE;
> - printk(KERN_INFO "%s: header compression turned on\n", sl->dev->name);
> + printk(KERN_INFO "%s: header compression turned on\n", dev->name);
> }
> sl->rbuff[0] &= 0x4f;
> if (slhc_remember(sl->slcomp, sl->rbuff, count) <= 0)
> @@ -355,20 +356,20 @@ static void sl_bump(struct slip *sl)
> }
> #endif /* SL_INCLUDE_CSLIP */
>
> - sl->rx_bytes += count;
> + dev->stats.rx_bytes += count;
>
> skb = dev_alloc_skb(count);
> if (skb == NULL) {
> - printk(KERN_WARNING "%s: memory squeeze, dropping packet.\n", sl->dev->name);
> - sl->rx_dropped++;
> + printk(KERN_WARNING "%s: memory squeeze, dropping packet.\n", dev->name);
> + dev->stats.rx_dropped++;
> return;
> }
> - skb->dev = sl->dev;
> + skb->dev = dev;
> memcpy(skb_put(skb, count), sl->rbuff, count);
> skb_reset_mac_header(skb);
> skb->protocol = htons(ETH_P_IP);
> netif_rx(skb);
> - sl->rx_packets++;
> + dev->stats.rx_packets++;
> }
>
> /* Encapsulate one IP datagram and stuff into a TTY queue. */
> @@ -379,7 +380,7 @@ static void sl_encaps(struct slip *sl, unsigned char *icp, int len)
>
> if (len > sl->mtu) { /* Sigh, shouldn't occur BUT ... */
> printk(KERN_WARNING "%s: truncating oversized transmit packet!\n", sl->dev->name);
> - sl->tx_dropped++;
> + sl->dev->stats.tx_dropped++;
> sl_unlock(sl);
> return;
> }
> @@ -433,7 +434,7 @@ static void slip_write_wakeup(struct tty_struct *tty)
> if (sl->xleft <= 0) {
> /* Now serial buffer is almost free & we can start
> * transmission of another packet */
> - sl->tx_packets++;
> + sl->dev->stats.tx_packets++;
> clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
> sl_unlock(sl);
> return;
> @@ -496,7 +497,7 @@ sl_xmit(struct sk_buff *skb, struct net_device *dev)
> }
>
> sl_lock(sl);
> - sl->tx_bytes += skb->len;
> + dev->stats.tx_bytes += skb->len;
> sl_encaps(sl, skb->data, skb->len);
> spin_unlock(&sl->lock);
>
> @@ -562,12 +563,12 @@ static struct net_device_stats *
> sl_get_stats(struct net_device *dev)
> {
> struct net_device_stats *stats = &dev->stats;
> - struct slip *sl = netdev_priv(dev);
> - unsigned long c_rx_dropped = 0;
> #ifdef SL_INCLUDE_CSLIP
> + unsigned long c_rx_dropped = 0;
> unsigned long c_rx_fifo_errors = 0;
> unsigned long c_tx_fifo_errors = 0;
> unsigned long c_collisions = 0;
> + struct slip *sl = netdev_priv(dev);
> struct slcompress *comp = sl->slcomp;
>
> if (comp) {
> @@ -579,17 +580,9 @@ sl_get_stats(struct net_device *dev)
> stats->rx_fifo_errors = sl->rx_compressed + c_rx_fifo_errors;
> stats->tx_fifo_errors = sl->tx_compressed + c_tx_fifo_errors;
> stats->collisions = sl->tx_misses + c_collisions;
> + stats->rx_dropped += c_rx_dropped;

Sorry this bit is wrong.

You cannot do "stats->somefield += somevalue", since its cumulative for
each call to "cat /proc/net/dev"

> #endif
>
> - stats->rx_packets = sl->rx_packets;
> - stats->tx_packets = sl->tx_packets;
> - stats->rx_bytes = sl->rx_bytes;
> - stats->tx_bytes = sl->tx_bytes;
> - stats->rx_dropped = sl->rx_dropped + c_rx_dropped;
> - stats->tx_dropped = sl->tx_dropped;
> - stats->tx_errors = sl->tx_errors;
> - stats->rx_errors = sl->rx_errors;
> - stats->rx_over_errors = sl->rx_over_errors;
> return stats;
> }
>
> @@ -681,7 +674,7 @@ static void slip_receive_buf(struct tty_struct *tty, const unsigned char *cp,
> while (count--) {
> if (fp && *fp++) {
> if (!test_and_set_bit(SLF_ERROR, &sl->flags))
> - sl->rx_errors++;
> + sl->dev->stats.rx_errors++;
> cp++;
> continue;
> }
> @@ -981,7 +974,7 @@ static void slip_unesc(struct slip *sl, unsigned char s)
> sl->rbuff[sl->rcount++] = s;
> return;
> }
> - sl->rx_over_errors++;
> + sl->dev->stats.rx_over_errors++;
> set_bit(SLF_ERROR, &sl->flags);
> }
> }
> @@ -1057,7 +1050,7 @@ static void slip_unesc6(struct slip *sl, unsigned char s)
> sl->rbuff[sl->rcount++] = c;
> return;
> }
> - sl->rx_over_errors++;
> + sl->dev->stats.rx_over_errors++;
> set_bit(SLF_ERROR, &sl->flags);
> }
> }
> diff --git a/drivers/net/slip.h b/drivers/net/slip.h
> index 9ea5c11..914e958 100644
> --- a/drivers/net/slip.h
> +++ b/drivers/net/slip.h
> @@ -67,15 +67,6 @@ struct slip {
> int xleft; /* bytes left in XMIT queue */
>
> /* SLIP interface statistics. */
> - unsigned long rx_packets; /* inbound frames counter */
> - unsigned long tx_packets; /* outbound frames counter */
> - unsigned long rx_bytes; /* inbound byte counte */
> - unsigned long tx_bytes; /* outbound byte counter */
> - unsigned long rx_errors; /* Parity, etc. errors */
> - unsigned long tx_errors; /* Planned stuff */
> - unsigned long rx_dropped; /* No memory for skb */
> - unsigned long tx_dropped; /* When MTU change */
> - unsigned long rx_over_errors; /* Frame bigger than SLIP buf. */
> #ifdef SL_INCLUDE_CSLIP
> unsigned long tx_compressed;
> unsigned long rx_compressed;