> -----Original Message----- > From: Jerin Jacob [mailto:[email protected]] > Sent: Monday, February 6, 2017 9:25 AM > To: Van Haaren, Harry <[email protected]> > Cc: [email protected]; Richardson, Bruce <[email protected]> > Subject: Re: [PATCH v2 07/15] event/sw: add support for event queues > > On Tue, Jan 31, 2017 at 04:14:25PM +0000, Harry van Haaren wrote: > > From: Bruce Richardson <[email protected]> > > > > Add in the data structures for the event queues, and the eventdev > > functions to create and destroy those queues. > > > > Signed-off-by: Bruce Richardson <[email protected]> > > Signed-off-by: Harry van Haaren <[email protected]> > > --- > > drivers/event/sw/iq_ring.h | 176 > > ++++++++++++++++++++++++++++++++++++++++++++ > > drivers/event/sw/sw_evdev.c | 158 +++++++++++++++++++++++++++++++++++++++ > > drivers/event/sw/sw_evdev.h | 75 +++++++++++++++++++ > > 3 files changed, 409 insertions(+) > > create mode 100644 drivers/event/sw/iq_ring.h > > > > + */ > > + > > +/* > > + * Ring structure definitions used for the internal ring buffers of the > > + * SW eventdev implementation. These are designed for single-core use only. > > + */ > > If I understand it correctly, IQ and QE rings are single producer and > single consumer rings. By the specification, multiple producers through > multiple ports can enqueue to the event queues at a time.Does SW > implementation > support that? or am I missing something here?
You're right that the IQ and QE rings are Single Producer, Single Consumer rings. More specifically, the QE is a ring for sending rte_event structs between cores, while the IQ ring is optimized for internal use in the scheduler core - and should not be used to send events between cores. Note that the design of the SW scheduler includes a central core for performing scheduling. In other works, the QE rings transfer events from the worker core to the scheduler - and the scheduler pushes the events into what you call the "event queues" (aka, the atomic/ordered queue itself). These "event queues" are IQ instances. On egress from the scheduler, the event passes through a QE ring to the worker. The result is that despite that only SP/SC rings are used, multiple workers can enqueue to any event queue.
