Hi Jerin, Thanks for the update. I think we can add this new flag in 17.08. I prefer waiting John's review, especially for doc wording, before applying it. I consider it does not hurt to add it post-rc1.
See below for my first comment on the doc. 06/07/2017 08:21, Jerin Jacob: > 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. > > v2: > - Changed the flag name to DEV_TX_OFFLOAD_MT_LOCKFREE(Thomas) > - Updated the documentation in doc/guides/prog_guide/poll_mode_drv.rst > and rte_eth_tx_burst() doxgen comments(Thomas) > > Signed-off-by: Jerin Jacob <jerin.ja...@caviumnetworks.com> > --- [...] > +If the PMD is ``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 found in > some NICs and A space is missing after the dot. Note: my preference is to start next sentence on a new line (in RST source). > +useful in the following use cases if PMD supports it. See `Hardware > Offload`_ for details. This sentence is confusing. I would remove "if PMD supports it". After "following use cases", should we add a colon? The relation with `Hardware Offload`_ is not obvious. > +* Remove explicit spinlock in some applications where lcores to TX queues > are not mapped 1:1. Can we reword "lcores to TX queues"? I suggest "lcores are not mapped to Tx queues with 1:1 relation". > +* In the eventdev use case, Avoid dedicating a separate TX core for > transmitting and thus Uppercase in the middle of the sentence spotted. > + enables more scaling as all workers can send the packets.
