Re: [dpdk-dev] [PATCH v3 ] ethdev: introduce lock-free txq capability flag

[Thomas Monjalon <thomas@monjalon.net>]

13/07/2017 15:02, Hemant Agrawal:
> On 7/10/2017 10:29 PM, Jerin Jacob wrote:
> > Introducing the DEV_TX_OFFLOAD_MT_LOCKFREE TX capability flag.
> > if a PMD advertises DEV_TX_OFFLOAD_MT_LOCKFREE capable, multiple threads
> > can invoke rte_eth_tx_burst() concurrently on the same tx queue without
> > SW lock. This PMD feature will be useful in the following use cases and
> > found in the OCTEON family of NPUs.
> >
> > 1) Remove explicit spinlock in some applications where lcores
> > to TX queues are not mapped 1:1.
> > example: OVS has such instance
> > https://github.com/openvswitch/ovs/blob/master/lib/netdev-dpdk.c#L299
> > https://github.com/openvswitch/ovs/blob/master/lib/netdev-dpdk.c#L1859
> > See the the usage of tx_lock spinlock.
> >
> > 2) In the eventdev use case, avoid dedicating a separate TX core for
> > transmitting and thus enables more scaling as all workers can
> > send the packets.
> >
> > Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
> 
> You may also like to add this capability in "doc/guides/nics/features/*.ini"

I've just added the feature "Lock-free Tx queue" in features/default.ini.

> Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>

Applied, thanks