-----Original Message-----
> Date: Mon, 17 Sep 2018 16:17:24 +0800
> From: Gavin Hu <gavin...@arm.com>
> To: dev@dpdk.org
> CC: gavin...@arm.com, honnappa.nagaraha...@arm.com, steve.cap...@arm.com,
> ola.liljed...@arm.com, jerin.ja...@caviumnetworks.com, n...@arm.com,
> sta...@dpdk.org
> Subject: [PATCH v3 3/3] ring: move the atomic load of head above the loop
> X-Mailer: git-send-email 2.7.4
>
> External Email
>
> In __rte_ring_move_prod_head, move the __atomic_load_n up and out of
> the do {} while loop as upon failure the old_head will be updated,
> another load is costly and not necessary.
>
> This helps a little on the latency,about 1~5%.
>
> Test result with the patch(two cores):
> SP/SC bulk enq/dequeue (size: 8): 5.64
> MP/MC bulk enq/dequeue (size: 8): 9.58
> SP/SC bulk enq/dequeue (size: 32): 1.98
> MP/MC bulk enq/dequeue (size: 32): 2.30
>
> Fixes: 39368ebfc6 ("ring: introduce C11 memory model barrier option")
> Cc: sta...@dpdk.org
>
> Signed-off-by: Gavin Hu <gavin...@arm.com>
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com>
> Reviewed-by: Steve Capper <steve.cap...@arm.com>
> Reviewed-by: Ola Liljedahl <ola.liljed...@arm.com>
Acked-by: Jerin Jacob <jerin.ja...@caviumnetworks.com>
Tested-by: Jerin Jacob <jerin.ja...@caviumnetworks.com>
