[dpdk-dev] [PATCH v1] net/memif: optimized with one-way barrier

[Jakub Grajciar -X (jgrajcia - PANTHEON TECHNOLOGIES at Cisco)]

> > > > -----Original Message-----
> > > > From: dev <dev-bounces at dpdk.org> On Behalf Of Phil Yang
> > > > Sent: Monday, August 26, 2019 7:00 PM
> > > > To: jgrajcia at cisco.com; dev at dpdk.org
> > > > Cc: thomas at monjalon.net; jerinj at marvell.com; Honnappa Nagarahalli
> > > > <Honnappa.Nagarahalli at arm.com>; damarion at cisco.com; nd
> > > <nd at arm.com>
> > > > Subject: [dpdk-dev] [PATCH v1] net/memif: optimized with one-way
> > > > barrier
> > > >
> > > > Using 'rte_mb' to synchronize the shared ring head/tail between
> > > > producer and consumer will stall the pipeline and damage
> > > > performance on the weak memory model platforms, such like aarch64.
> > > > Meanwhile update the shared ring head and tail are observable and
> > > > ordered
> > between
> > > CPUs on IA.
> > > >
> > > > Optimized this full barrier with the one-way barrier can improve
> > > > the throughput. On aarch64 n1sdp server this patch make testpmd
> > throughput
> > > > boost 2.1%. On Intel E5-2640, testpmd got 3.98% performance gain.
> > > >
> > > > Signed-off-by: Phil Yang <phil.yang at arm.com>
> > > > Reviewed-by: Gavin Hu <gavin.hu at arm.com>
> >
> > The patch is looking good, but 'MEMIF_VERSION_MAJOR' in memif.h needs
> > to be set to 3 as ring pointers are no longer volatile.
> 
> Updated in v2.
> Thanks for your comments.
> 
> Thanks,
> Phil

I jumped the gun with the version bump. The change doesn't break compatibility. I'm putting reviewed label on v1.

Sorry for the inconvenience.

Reviewed-by: Jakub Grajciar <jgrajcia at cisco.com>