On Thu, Jan 22, 2015 at 07:23:49PM +0900, Tetsuya Mukawa wrote: > On 2015/01/22 16:35, Matthew Hall wrote: > > On Thu, Jan 22, 2015 at 01:32:04PM +0800, Linhaifeng wrote: > >> Do you mean if call rte_memcpy before rte_eal_init() would crash?why? > > No guarantee. But a theory. It might use some things from the EAL init to > > figure out which version of the accelerated algorithm to use. > > This selection is done at compile-time. > And if the size is constant, I guess DPDK assumes memcpy is replaced by > inline __builtin_memcpy. > I haven't checked the performance of builtin memcpy, but probably much > faster. >
Yes, that assumption is correct. A couple of years ago we discovered that for constant size values, the compiler would generate much faster code for us using a regular memcpy than rte_memcpy, hence the macro. /Bruce > Tetsuya > > > Matthew. > >
