-----Original Message-----
From: Pavan Nikhilesh Bhagavatula <redacted>
Sent: Wednesday, March 24, 2021 12:15 PM
To: Jayatheerthan, Jay <redacted>; Jerin Jacob Kollanukkaran <redacted>; Carrillo, Erik G
[off-list ref]; Gujjar, Abhinandan S [off-list ref]; McDaniel, Timothy
[off-list ref]; hemant.agrawal@nxp.com; Van Haaren, Harry [off-list ref]; mattias.ronnblom
[off-list ref]; Ma, Liang J [off-list ref]
Cc: dev@dpdk.org
Subject: RE: [dpdk-dev] [PATCH v5 0/8] Introduce event vectorization

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From: pbhagavatula@marvell.com <redacted>
Sent: Wednesday, March 24, 2021 10:35 AM
To: jerinj@marvell.com; Jayatheerthan, Jay

[off-list ref]; Carrillo, Erik G
[off-list ref]; Gujjar, Abhinandan

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S [off-list ref]; McDaniel, Timothy

[off-list ref]; hemant.agrawal@nxp.com; Van
Haaren, Harry

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[off-list ref]; mattias.ronnblom

[off-list ref]; Ma, Liang J
[off-list ref]

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Cc: dev@dpdk.org; Pavan Nikhilesh <redacted>
Subject: [dpdk-dev] [PATCH v5 0/8] Introduce event vectorization

From: Pavan Nikhilesh <redacted>

In traditional event programming model, events are identified by a
flow-id and a uintptr_t. The flow-id uniquely identifies a given event
and determines the order of scheduling based on schedule type, the
uintptr_t holds a single object.

Event devices also support burst mode with configurable dequeue

depth,

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i.e. each dequeue call would return multiple events and each event
might be at a different stage of the pipeline.
Having a burst of events belonging to different stages in a dequeue
burst is not only difficult to vectorize but also increases the scheduler
overhead and application overhead of pipelining events further.
Using event vectors we see a performance gain of ~628% as shown in

[1].
This is very impressive performance boost. Thanks so much for putting
this patchset together! Just curious, was any performance
measurement done for existing applications (non-vector)?

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By introducing event vectorization, each event will be capable of

holding

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multiple uintptr_t of the same flow thereby allowing applications
to vectorize their pipeline and reduce the complexity of pipelining
events across multiple stages. This also reduces the complexity of

handling

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enqueue and dequeue on an event device.

Since event devices are transparent to the events they are scheduling
so the event producers such as eth_rx_adapter, crypto_adapter , etc..
are responsible for vectorizing the buffers of the same flow into a

single

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event.

The series also breaks ABI in the patch [8/8] which is targetted to the
v21.11 release.

The dpdk-test-eventdev application has been updated with options to

test

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multiple vector sizes and timeouts.

[1]
As for performance improvement, with a ARM Cortex-A72 equivalent

processer,

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software event device (--vdev=event_sw0), single worker core, single

stage

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and using one service core for Rx adapter, Tx adapter, Scheduling.

Without event vectorization:
    ./build/app/dpdk-test-eventdev -l 7-23 -s 0x700 --

vdev="event_sw0" --

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         --prod_type_ethdev --nb_pkts=0 --verbose 2 --

test=pipeline_queue

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         --stlist=a --wlcores=20
    Port[0] using Rx adapter[0] configured
    Port[0] using Tx adapter[0] Configured
    4.728 mpps avg 4.728 mpps

Is this number before the patchset? If so, it would help put similar
number with the patchset but not using vectorization feature.

I don’t remember the exact clock frequency I was using when I ran
the above test but with equal clocks:
1. Without the patchset applied
	5.071 mpps
2. With patchset applied w/o enabling vector
	5.123 mpps
3. With patchset applied with enabling vector
	vector_sz@256 42.715 mpps
	vector_sz@512 45.335 mpps

Thanks Pavan for the details. It may be useful to include this info in the patchset.

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With event vectorization:
    ./build/app/dpdk-test-eventdev -l 7-23 -s 0x700 --

vdev="event_sw0" --

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        --prod_type_ethdev --nb_pkts=0 --verbose 2 --

test=pipeline_queue

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        --stlist=a --wlcores=20 --enable_vector --nb_eth_queues 1
        --vector_size 256
    Port[0] using Rx adapter[0] configured
    Port[0] using Tx adapter[0] Configured
    34.383 mpps avg 34.383 mpps

Having dedicated service cores for each Rx queues and tweaking the

vector,

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dequeue burst size would further improve performance.

API usage is shown below:

Configuration:

	struct rte_event_eth_rx_adapter_event_vector_config

vec_conf;

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	vector_pool = rte_event_vector_pool_create("vector_pool",
			nb_elem, 0, vector_size, socket_id);

	rte_event_eth_rx_adapter_create(id, event_id, &adptr_conf);
	rte_event_eth_rx_adapter_queue_add(id, eth_id, -1,

&queue_conf);

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	if (cap & RTE_EVENT_ETH_RX_ADAPTER_CAP_EVENT_VECTOR)

{

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		vec_conf.vector_sz = vector_size;
		vec_conf.vector_timeout_ns = vector_tmo_nsec;
		vec_conf.vector_mp = vector_pool;

rte_event_eth_rx_adapter_queue_event_vector_config(id,

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				eth_id, -1, &vec_conf);
	}

Fastpath:

	num = rte_event_dequeue_burst(event_id, port_id, &ev, 1, 0);
	if (!num)
		continue;

	if (ev.event_type & RTE_EVENT_TYPE_VECTOR) {
		switch (ev.event_type) {
		case RTE_EVENT_TYPE_ETHDEV_VECTOR:
		case RTE_EVENT_TYPE_ETH_RX_ADAPTER_VECTOR:
			struct rte_mbuf **mbufs;

			mbufs = ev.vector_ev->mbufs;
			for (i = 0; i < ev.vector_ev->nb_elem; i++)
				//Process mbufs.
			break;
		case ...
		}
	}
	...

v5 Changes:
- Make `rte_event_vector_pool_create non-inline` to ease ABI

stability.(Ray)

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- Move `rte_event_eth_rx_adapter_queue_event_vector_config` and
  `rte_event_eth_rx_adapter_vector_limits_get` implementation to

the patch

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  where they are initially defined.(Ray)
- Multiple gramatical and style fixes.(Jerin)
- Add missing release notes.(Jerin)

v4 Changes:
- Fix missing event vector structure in event structure.(Jay)

v3 Changes:
- Fix unintended formatting changes.

v2 Changes:
- Multiple gramatical and style fixes.(Jerin)
- Add parameter to define vector size in power of 2. (Jerin)
- Redo patch series w/o breaking ABI till the last patch.(David)
- Add deprication notice to announce ABI break in 21.11.(David)
- Add vector limits validation to app/test-eventdev.

Pavan Nikhilesh (8):
  eventdev: introduce event vector capability
  eventdev: introduce event vector Rx capability
  eventdev: introduce event vector Tx capability
  eventdev: add Rx adapter event vector support
  eventdev: add Tx adapter event vector support
  app/eventdev: add event vector mode in pipeline test
  doc: announce event Rx adapter config changes
  eventdev: simplify Rx adapter event vector config

 app/test-eventdev/evt_common.h                |   4 +
 app/test-eventdev/evt_options.c               |  52 +++
 app/test-eventdev/evt_options.h               |   4 +
 app/test-eventdev/test_pipeline_atq.c         | 310 +++++++++++++++--
 app/test-eventdev/test_pipeline_common.c      | 105 +++++-
 app/test-eventdev/test_pipeline_common.h      |  18 +
 app/test-eventdev/test_pipeline_queue.c       | 320

++++++++++++++++--

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 .../prog_guide/event_ethernet_rx_adapter.rst  |  38 +++
 .../prog_guide/event_ethernet_tx_adapter.rst  |  12 +
 doc/guides/prog_guide/eventdev.rst            |  36 +-
 doc/guides/rel_notes/deprecation.rst          |   9 +
 doc/guides/rel_notes/release_21_05.rst        |   8 +
 doc/guides/tools/testeventdev.rst             |  45 ++-
 lib/librte_eventdev/eventdev_pmd.h            |  31 +-
 .../rte_event_eth_rx_adapter.c                | 305 ++++++++++++++++-
 .../rte_event_eth_rx_adapter.h                |  78 +++++
 .../rte_event_eth_tx_adapter.c                |  66 +++-
 lib/librte_eventdev/rte_eventdev.c            |  53 ++-
 lib/librte_eventdev/rte_eventdev.h            | 113 ++++++-
 lib/librte_eventdev/version.map               |   4 +
 20 files changed, 1524 insertions(+), 87 deletions(-)

--
2.17.1

Just a heads up. v5 patchset doesn't apply cleanly on HEAD
(5f0849c1155849dfdbf950c91c52cdf9cd301f59). Although, it applies
cleanly on app/eventdev: fix timeout accuracy
(c33d48387dc8ccf1b432820f6e0cd4992ab486df).

This patchset is currently rebased on main branch, I will rebase it on
dpdk-next-event in next version.