On 7/18/14, lx <lxlenovostar@xxxxxxxxx> wrote: > hi : > the source code of net_rx(struct net_device *dev) is: > http://lxr.oss.org.cn/source/drivers/net/ethernet/cirrus/cs89x0.c#L670 > > I can't understand codes about malloc buffer. > ########################################## > 684 /* Malloc up new buffer. */ > 685 skb = netdev_alloc_skb(dev, length + 2); > 686 if (skb == NULL) { > 687 dev->stats.rx_dropped++; > 688 return; > 689 } > 690 skb_reserve(skb, 2); /* longword align L3 header */ > ########################################## > > How to explain 'length + 2' in line of 685? Why add 2 ? That's why it's explained on the line 690. http://lwn.net/Articles/89597/ > Thank you. > > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > -- Regards, Denis _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
