On Wed, 15 Apr 2015 21:46:27 +0800 Dong.Wang <dong.wang.pro at hotmail.com> wrote:
> Yes, current implementation works well with IA, and the transmit packets > function's rte_wmb() is also unneccessary. > > But there are two reasons for adding rte_wmb() in recv pkts function: > 1) The memory barrier in recv pkts function and xmit pkts function are > inconsistent, rte_wmb() should be added to recv pkts function or be > removed from xmit pkts function. > 2) DPDK will support PowerPC processor (Other developers are working on > it), I check the memory ordering of PowerPC, there was no mention of > store-store instruction's principle in MPC8544 Reference Manual, only > said it is weak memory ordering. > > So, I think it is neccessary to add rte_wmb() to recv pkts function. > > Dong If PowerPC requires additional memory barriers then it should introduce a new generic set of memory barrier macros that are no-ops on other architectures. Please don't penalize x86 for places where other CPU's have weaker consistency.
