On Tue, 2014-08-26 at 09:10 +0000, David Laight wrote: > From: Arnd Bergmann
> > While this seems correct, I wonder why you don't do the normal approach of > > dequeuing the skb from the chain and adding a newly allocated skb to it to > > save the memcpy. > > Because the receive buffer area isn't made of skbs. > Post-allocating the skb also reduces the 'true size' of the skb. This strategy assumes this is not a 10Gbe NIC. We try to avoid copies because they are generally not needed. Wifi devices are usually slow, and packet losses are more frequent, so the copybreak gives better chance to not doing the collapses [1] later in the TCP stack. [1] collapses : reducing skb overhead (skb->len / skb->truesize ratio) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
