[dpdk-dev] [PATCH v2 2/2] eal/x86: Use lock-prefixed instructions to reduce cost of rte_smp_mb()

[Bruce Richardson]

On Mon, Dec 18, 2017 at 03:34:13PM +0000, Konstantin Ananyev wrote:
> On x86 it  is possible to use lock-prefixed instructions to get
> the similar effect as mfence.
> As pointed by Java guys, on most modern HW that gives a better
> performance than using mfence:
> https://shipilev.net/blog/2014/on-the-fence-with-dependencies/
> That patch adopts that technique for rte_smp_mb() implementation.
> On BDW 2.2 mb_autotest on single lcore reports 2X cycle reduction,
> i.e. from ~110 to ~55 cycles per operation.
> 
> Signed-off-by: Konstantin Ananyev <konstantin.ananyev at intel.com>
> ---
Acked-by: Bruce Richardson <bruce.richardson at intel.com>