27/04/2017 13:00, Jerin Jacob: > -----Original Message----- > > Date: Mon, 24 Apr 2017 14:34:59 +0200 > > From: Thomas Monjalon <tho...@monjalon.net> > > To: Jerin Jacob <jerin.ja...@caviumnetworks.com> > > Cc: dev@dpdk.org, bruce.richard...@intel.com, harry.van.haa...@intel.com, > > hemant.agra...@nxp.com, gage.e...@intel.com, nipun.gu...@nxp.com, > > santosh.shu...@caviumnetworks.com > > Subject: Re: [dpdk-dev] [PATCH] ethdev: add lock-less txq capability flag > > > > 21/04/2017 14:22, Jerin Jacob: > > > if this flag is advertised by a PMD, Multiple threads can > > > invoke rte_eth_tx_burst() concurrently on the same tx queue > > > without SW lock. This is an HW feature found in some NICs > > > and useful in the following use cases if HW supports it. > > > > Which hardware supports it? > > Cavium OCTEONTX Packet transmission HW block(PKO). > > > > > [...] > > > --- a/lib/librte_ether/rte_ethdev.h > > > +++ b/lib/librte_ether/rte_ethdev.h > > > +#define DEV_TX_OFFLOAD_TXQ_MT_LOCKFREE 0x00004000 > > > +/**< Multiple threads can invoke rte_eth_tx_burst() concurrently on the > > > same + * tx queue without SW lock. > > > + */ > > > > Why TXQ in the name? DEV_TX_OFFLOAD_MT_LOCKFREE would be enough. > > OK > > > I wonder whether "lock free" wording is confusing because > > the locks are probably handled in HW. > > Yes. Another reason why it possible because HW is not using ring like > scheme(head and tail pointers) > for Tx. "lock free" wording is more from software perspective. > > > I think the good wording is "offloaded multi-thread capability", > > maybe with a naming like DEV_TX_OFFLOAD_MT. > > I think SW lock free is the capability here.IMO, it better to reflect the > capability in the name(DEV_TX_OFFLOAD_MT_LOCKFREE). > > > > > Anyway we should reference this flag in rte_eth_tx_burst() > > and give more details in doc/guides/prog_guide/poll_mode_drv.rst. > > OK. Will address in v2. > > > > > Should we wait a first hardware PoC to add this flag? > > If we are in agreement for method expose this feature through capability > flag then should we really need to wait for driver implementation to > accept the patch? Thoughts ? > This flag has impact on how we handle the even dev applications if HW support > available. > We are in the process of up-streaming OCTEONTX ethdev driver, but there > are few thing like with external pool manager and eventdev integration > needs to be sorted out cleanly before that. > > > Candidate for 17.08?
Any news of a v2?
