Hi Jiangbo, On Thu, Dec 15, 2016 at 08:40:19PM -0800, Santosh Shukla wrote: > On Thu, Dec 15, 2016 at 04:37:12PM +0800, Jianbo Liu wrote: > > On 14 December 2016 at 09:55, Jerin Jacob > > <jerin.ja...@caviumnetworks.com> wrote: > > > From: Santosh Shukla <santosh.shu...@caviumnetworks.com> > > > > > > > memory barrier operation is put inside IXGBE_PCI_REG_READ/WRITE in > > your change, but I found rte_*mb is called before these macros in some > > places. > > Can you remove all these redundant calls? And please do the same > > checking for other drivers. > > > > Ok. > > Thinking of adding _relaxed_rd/wr style macro agnostic to arch for ixgbe case > in particular. Such that for those code incident: > x86 case> first default barrier + relaxed call. > arm case> first default barrier + relaxed call. > > Does that make sense to you? If so then will take care in v2. > > Santosh.
We spend time looking at drivers code where double barrier may happen. Most of them are in driver init path, configuration/control path code. So keeping double barrier won't impact performance. We plan to replace only fast path code with _relaxed style API's. That way we won't impact each driver performance and we'll have the clean port. Does it make sense? Thought? > > > > #define IXGBE_PCI_REG_ADDR(hw, reg) \ > > > ((volatile uint32_t *)((char *)(hw)->hw_addr + (reg))) > > > -- > > > 2.5.5 > > >
