On 05/03/2016 11:45 AM, Bruce Richardson wrote: > On Mon, May 02, 2016 at 05:29:37PM +0530, Jerin Jacob wrote: >> prefetch the next packet data address in advance in macswap loop >> for performance improvement. >> >> ... >> for (i = 0; i < nb_rx; i++) { >> + if (likely(i < nb_rx - 1)) >> + rte_prefetch0(rte_pktmbuf_mtod(pkts_burst[i + 1], >> + void *)); > > At least on IA platforms, there is no issue with prefetching beyond the end of > the array, since it's only a hint to the cpu. If this is true for other > platforms, > then I suggest we just drop the conditional and just always prefetch.
This is an interesting point. Bruce, are you suggesting that prefetching at an invalid [virtual] address won't trigger a CPU exception? Ivan > > /Bruce > >> mb = pkts_burst[i]; >> eth_hdr = rte_pktmbuf_mtod(mb, struct ether_hdr *);