quoted

-----Original Message-----
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,

quoted

Abhinandan S [off-list ref]; McDaniel, Timothy

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

quoted

Haaren, Harry [off-list ref]; mattias.ronnblom

[off-list ref]; Ma, Liang J

quoted

[off-list ref]; Ray Kinsella [off-list ref]; Neil Horman

[off-list ref]

quoted

Cc: dev@dpdk.org; Pavan Nikhilesh <redacted>
Subject: [dpdk-dev] [PATCH v5 1/8] eventdev: introduce event vector

capability

quoted

From: Pavan Nikhilesh <redacted>

Introduce rte_event_vector datastructure which is capable of holding
multiple uintptr_t of the same flow thereby allowing applications
to vectorize their pipeline and reducing the complexity of pipelining
the events across multiple stages.
This approach also reduces the scheduling overhead on a event

device.

quoted

Add a event vector mempool create handler to create mempools

based on

quoted

the best mempool ops available on a given platform.

Signed-off-by: Pavan Nikhilesh <redacted>
Acked-by: Jerin Jacob <redacted>
---
 doc/guides/prog_guide/eventdev.rst     | 36 +++++++++++-
 doc/guides/rel_notes/release_21_05.rst |  8 +++
 lib/librte_eventdev/rte_eventdev.c     | 42 +++++++++++++
 lib/librte_eventdev/rte_eventdev.h     | 81

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

quoted

 lib/librte_eventdev/version.map        |  3 +
 5 files changed, 167 insertions(+), 3 deletions(-)

diff --git a/doc/guides/prog_guide/eventdev.rst

b/doc/guides/prog_guide/eventdev.rst

quoted

index ccde086f6..fda9c3743 100644

--- a/doc/guides/prog_guide/eventdev.rst
+++ b/doc/guides/prog_guide/eventdev.rst

@@ -63,13 +63,45 @@ the actual event being scheduled is. The

payload is a union of the following:

quoted

 * ``uint64_t u64``
 * ``void *event_ptr``
 * ``struct rte_mbuf *mbuf``
+* ``struct rte_event_vector *vec``

-These three items in a union occupy the same 64 bits at the end of

the rte_event

quoted

+These four items in a union occupy the same 64 bits at the end of the

rte_event

quoted

 structure. The application can utilize the 64 bits directly by accessing

the

quoted

-u64 variable, while the event_ptr and mbuf are provided as

convenience

quoted

+u64 variable, while the event_ptr, mbuf, vec are provided as a

convenience

quoted

 variables.  For example the mbuf pointer in the union can used to

schedule a

quoted

 DPDK packet.

+Event Vector
+~~~~~~~~~~~~
+
+The rte_event_vector struct contains a vector of elements defined

by the event

quoted

+type specified in the ``rte_event``. The event_vector structure

contains the

quoted

+following data:
+
+* ``nb_elem`` - The number of elements held within the vector.
+
+Similar to ``rte_event`` the payload of event vector is also a union,

allowing

quoted

+flexibility in what the actual vector is.
+
+* ``struct rte_mbuf *mbufs[0]`` - An array of mbufs.
+* ``void *ptrs[0]`` - An array of pointers.
+* ``uint64_t *u64s[0]`` - An array of uint64_t elements.
+
+The size of the event vector is related to the total number of

elements it is

quoted

+configured to hold, this is achieved by making `rte_event_vector` a

variable

quoted

+length structure.
+A helper function is provided to create a mempool that holds event

vector, which

quoted

+takes name of the pool, total number of required

``rte_event_vector``,

quoted

+cache size, number of elements in each ``rte_event_vector`` and

socket id.

quoted

+
+.. code-block:: c
+
+        rte_event_vector_pool_create("vector_pool",

nb_event_vectors, cache_sz,

quoted

+                                     nb_elements_per_vector, socket_id);
+
+The function ``rte_event_vector_pool_create`` creates mempool

with the best

quoted

+platform mempool ops.
+
 Queues
 ~~~~~~

diff --git a/doc/guides/rel_notes/release_21_05.rst

b/doc/guides/rel_notes/release_21_05.rst

quoted

index 8e686cc62..358623f2f 100644

--- a/doc/guides/rel_notes/release_21_05.rst
+++ b/doc/guides/rel_notes/release_21_05.rst

@@ -101,6 +101,14 @@ New Features
   * Added command to display Rx queue used descriptor count.
     ``show port (port_id) rxq (queue_id) desc used count``

+* **Add Event device vector capability.**
+
+  * Added ``rte_event_vector`` data structure which is capable of

holding

quoted

+    multiple ``uintptr_t`` of the same flow thereby allowing

applications

quoted

+    to vectorize their pipelines and also reduce the complexity of

pipelining

quoted

+    the events across multiple stages.
+  * This also reduces the scheduling overhead on a event device.
+

 Removed Items
 -------------

diff --git a/lib/librte_eventdev/rte_eventdev.c

b/lib/librte_eventdev/rte_eventdev.c

quoted

index b57363f80..f95edc075 100644

--- a/lib/librte_eventdev/rte_eventdev.c
+++ b/lib/librte_eventdev/rte_eventdev.c

@@ -1266,6 +1266,48 @@ int rte_event_dev_selftest(uint8_t dev_id)
 	return -ENOTSUP;
 }

+struct rte_mempool *
+rte_event_vector_pool_create(const char *name, unsigned int n,
+			     unsigned int cache_size, uint16_t nb_elem,
+			     int socket_id)
+{
+	const char *mp_ops_name;
+	struct rte_mempool *mp;
+	unsigned int elt_sz;
+	int ret;
+
+	if (!nb_elem) {
+		RTE_LOG(ERR, EVENTDEV,
+			"Invalid number of elements=%d requested\n",

nb_elem);

quoted

+		rte_errno = -EINVAL;

rte_mempool_create_empty() call below returns non-negative EINVAL.
Should we maintain consistency within same API call?

quoted

+		return NULL;
+	}
+
+	elt_sz =
+		sizeof(struct rte_event_vector) + (nb_elem *

sizeof(uintptr_t));

quoted

+	mp = rte_mempool_create_empty(name, n, elt_sz, cache_size,

0, socket_id,

quoted

+				      0);
+	if (mp == NULL)
+		return NULL;
+
+	mp_ops_name = rte_mbuf_best_mempool_ops();
+	ret = rte_mempool_set_ops_byname(mp, mp_ops_name,

NULL);

quoted

+	if (ret != 0) {
+		RTE_LOG(ERR, EVENTDEV, "error setting mempool

handler\n");

quoted

+		goto err;
+	}
+
+	ret = rte_mempool_populate_default(mp);
+	if (ret < 0)
+		goto err;
+
+	return mp;
+err:
+	rte_mempool_free(mp);
+	rte_errno = -ret;

rte_mempool_set_ops_byname() API already returns negative ret and
we are making it positive. DPDK has many instances of error/ret being
negative and positive. Probably a larger effort to make it consistent
would help in general.

Since rte_eventdev uses positive rte_errno, I will use the same here for
consistency.

quoted

+	return NULL;
+}
+
 int
 rte_event_dev_start(uint8_t dev_id)
 {

diff --git a/lib/librte_eventdev/rte_eventdev.h

b/lib/librte_eventdev/rte_eventdev.h

quoted

index ce1fc2ce0..aa4dd3959 100644

--- a/lib/librte_eventdev/rte_eventdev.h
+++ b/lib/librte_eventdev/rte_eventdev.h

@@ -212,8 +212,10 @@ extern "C" {

 #include <rte_common.h>
 #include <rte_config.h>
-#include <rte_memory.h>
 #include <rte_errno.h>
+#include <rte_mbuf_pool_ops.h>
+#include <rte_memory.h>
+#include <rte_mempool.h>

 #include "rte_eventdev_trace_fp.h"

@@ -913,6 +915,31 @@

rte_event_dev_stop_flush_callback_register(uint8_t dev_id,

quoted

 int
 rte_event_dev_close(uint8_t dev_id);

+/**
+ * Event vector structure.
+ */
+struct rte_event_vector {
+	uint64_t nb_elem : 16;
+	/**< Number of elements in this event vector. */
+	uint64_t rsvd : 48;
+	/**< Reserved for future use */
+	uint64_t impl_opaque;
+	/**< Implementation specific opaque value.
+	 * An implementation may use this field to hold implementation

specific

quoted

+	 * value to share between dequeue and enqueue operation.
+	 * The application should not modify this field.
+	 */
+	union {
+		struct rte_mbuf *mbufs[0];
+		void *ptrs[0];
+		uint64_t *u64s[0];
+	} __rte_aligned(16);
+	/**< Start of the vector array union. Depending upon the event

type the

quoted

+	 * vector array can be an array of mbufs or pointers or opaque

u64

quoted

+	 * values.
+	 */
+};
+
 /* Scheduler type definitions */
 #define RTE_SCHED_TYPE_ORDERED          0
 /**< Ordered scheduling

@@ -986,6 +1013,21 @@ rte_event_dev_close(uint8_t dev_id);
  */
 #define RTE_EVENT_TYPE_ETH_RX_ADAPTER   0x4
 /**< The event generated from event eth Rx adapter */
+#define RTE_EVENT_TYPE_VECTOR           0x8
+/**< Indicates that event is a vector.
+ * All vector event types should be a logical OR of

EVENT_TYPE_VECTOR.

quoted

+ * This simplifies the pipeline design as one can split processing the

events

quoted

+ * between vector events and normal event across event types.
+ * Example:
+ *	if (ev.event_type & RTE_EVENT_TYPE_VECTOR) {
+ *		// Classify and handle vector event.
+ *	} else {
+ *		// Classify and handle event.
+ *	}
+ */
+#define RTE_EVENT_TYPE_CPU_VECTOR

(RTE_EVENT_TYPE_VECTOR | RTE_EVENT_TYPE_CPU)

quoted

+/**< The event vector generated from cpu for pipelining. */
+
 #define RTE_EVENT_TYPE_MAX              0x10
 /**< Maximum number of event types */

@@ -1108,6 +1150,8 @@ struct rte_event {
 		/**< Opaque event pointer */
 		struct rte_mbuf *mbuf;
 		/**< mbuf pointer if dequeued event is associated with

mbuf */

quoted

+		struct rte_event_vector *vec;
+		/**< Event vector pointer. */
 	};
 };

@@ -2023,6 +2067,41 @@ rte_event_dev_xstats_reset(uint8_t

dev_id,

quoted

  */
 int rte_event_dev_selftest(uint8_t dev_id);

+/**
+ * Get the memory required per event vector based on the number of

elements per

quoted

+ * vector.
+ * This should be used to create the mempool that holds the event

vectors.

quoted

+ *
+ * @param name
+ *   The name of the vector pool.
+ * @param n
+ *   The number of elements in the mbuf pool.
+ * @param cache_size
+ *   Size of the per-core object cache. See rte_mempool_create() for
+ *   details.
+ * @param nb_elem
+ *   The number of elements then a single event vector should be

able to hold.

Typo: that instead of then.

quoted

+ * @param socket_id
+ *   The socket identifier where the memory should be allocated. The
+ *   value can be *SOCKET_ID_ANY* if there is no NUMA constraint

for the

quoted

+ *   reserved zone
+ *
+ * @return
+ *   The pointer to the newly allocated mempool, on success. NULL

on error

quoted

+ *   with rte_errno set appropriately. Possible rte_errno values

include:

quoted

+ *    - E_RTE_NO_CONFIG - function could not get pointer to

rte_config structure

quoted

+ *    - E_RTE_SECONDARY - function was called from a secondary

process instance

quoted

+ *    - EINVAL - cache size provided is too large, or priv_size is not

aligned.

quoted

+ *    - ENOSPC - the maximum number of memzones has already been

allocated

quoted

+ *    - EEXIST - a memzone with the same name already exists
+ *    - ENOMEM - no appropriate memory area found in which to

create memzone

rte_mempool_create_empty() can return ENAMETOOLONG if name is
too long.

quoted

+ */
+__rte_experimental
+struct rte_mempool *
+rte_event_vector_pool_create(const char *name, unsigned int n,
+			     unsigned int cache_size, uint16_t nb_elem,
+			     int socket_id);
+
 #ifdef __cplusplus
 }
 #endif

diff --git a/lib/librte_eventdev/version.map

b/lib/librte_eventdev/version.map

quoted

index 3e5c09cfd..a070ef56e 100644

--- a/lib/librte_eventdev/version.map
+++ b/lib/librte_eventdev/version.map

@@ -138,6 +138,9 @@ EXPERIMENTAL {
 	__rte_eventdev_trace_port_setup;
 	# added in 20.11
 	rte_event_pmd_pci_probe_named;
+
+	#added in 21.05
+	rte_event_vector_pool_create;
 };

 INTERNAL {
--

2.17.1