19/01/2018 07:10, Herbert Guan: > This patch provides an option to do rte_memcpy() using 'restrict' > qualifier, which can induce GCC to do optimizations by using more > efficient instructions, providing some performance gain over memcpy() > on some ARM64 platforms/enviroments. > > The memory copy performance differs between different ARM64 > platforms. And a more recent glibc (e.g. 2.23 or later) > can provide a better memcpy() performance compared to old glibc > versions. It's always suggested to use a more recent glibc if > possible, from which the entire system can get benefit. If for some > reason an old glibc has to be used, this patch is provided for an > alternative. > > This implementation can improve memory copy on some ARM64 > platforms, when an old glibc (e.g. 2.19, 2.17...) is being used. > It is disabled by default and needs "RTE_ARCH_ARM64_MEMCPY" > defined to activate. It's not always proving better performance > than memcpy() so users need to run DPDK unit test > "memcpy_perf_autotest" and customize parameters in "customization > section" in rte_memcpy_64.h for best performance. > > Compiler version will also impact the rte_memcpy() performance. > It's observed on some platforms and with the same code, GCC 7.2.0 > compiled binary can provide better performance than GCC 4.8.5. It's > suggested to use GCC 5.4.0 or later. > > Signed-off-by: Herbert Guan <herbert.g...@arm.com> > Acked-by: Jerin Jacob <jerin.ja...@caviumnetworks.com>
Applied, thanks
