On Mon, Feb 06, 2017 at 10:25:18AM +0000, Van Haaren, Harry wrote:

quoted

-----Original Message-----
From: Jerin Jacob [mailto:jerin.jacob@caviumnetworks.com]
Sent: Monday, February 6, 2017 9:25 AM
To: Van Haaren, Harry <redacted>
Cc: dev@dpdk.org; Richardson, Bruce <redacted>
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:

quoted

From: Bruce Richardson <redacted>

Add in the data structures for the event queues, and the eventdev
functions to create and destroy those queues.

Signed-off-by: Bruce Richardson <redacted>
Signed-off-by: Harry van Haaren <redacted>
---
 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.

Thanks Harry. One question though,
In RTE_EVENT_DEV_CAP_DISTRIBUTED_SCHED mode, multiple SW schedulers can
be active. Right? If so, We need multi consumer. Right?

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.

Got it.