From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 5BB8342502; Tue, 5 Sep 2023 10:19:14 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 3FAC540270; Tue, 5 Sep 2023 10:19:14 +0200 (CEST) Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by mails.dpdk.org (Postfix) with ESMTP id 06E5F4026A for ; Tue, 5 Sep 2023 10:19:13 +0200 (CEST) Received: from frapeml500006.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Rfyzy6kF2z6D8cT; Tue, 5 Sep 2023 16:17:50 +0800 (CST) Received: from frapeml500007.china.huawei.com (7.182.85.172) by frapeml500006.china.huawei.com (7.182.85.219) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Tue, 5 Sep 2023 10:19:10 +0200 Received: from frapeml500007.china.huawei.com ([7.182.85.172]) by frapeml500007.china.huawei.com ([7.182.85.172]) with mapi id 15.01.2507.031; Tue, 5 Sep 2023 10:19:10 +0200 From: Konstantin Ananyev To: Honnappa Nagarahalli , "jackmin@nvidia.com" , "konstantin.v.ananyev@yandex.ru" CC: "dev@dpdk.org" , Ruifeng Wang , "Aditya Ambadipudi" , Wathsala Wathawana Vithanage , nd , nd Subject: RE: [RFC] lib/st_ring: add single thread ring Thread-Topic: [RFC] lib/st_ring: add single thread ring Thread-Index: AQHZ0/V0Bhhm7ISam0G4Ph+ZQqSgMLAKhqaQgABmJICAAQ1tMA== Date: Tue, 5 Sep 2023 08:19:10 +0000 Message-ID: References: <20230821060420.3509667-1-honnappa.nagarahalli@arm.com> <0273f48a522f4d2f854596e0d7e6d835@huawei.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.206.138.42] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-CFilter-Loop: Reflected X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org > > > Add a single thread safe and multi-thread unsafe ring data structure. > > > This library provides an simple and efficient alternative to > > > multi-thread safe ring when multi-thread safety is not required. > > > > Just a thought: do we really need whole new library for that? > > From what I understand all we need right now just one extra function: > > rte_ring_mt_unsafe_prod_deque(...) > > Sorry for ugly name :) > > To dequeue N elems from prod.tail. > > Or you think there would be some extra advantages in ST version of the = ring: > > extra usages, better performance, etc.? > There are multiple implementations of the ST ring being used in other par= ts of DPDK. Mattias Ronnblom pointed out some (distributed > scheduler, eth RX adapter, cmdline) [1] existing ones which will be repla= ced by this one. > This implementation will not use atomic instructions, head and tail indic= es will be in the same cache line and it will be a double ended > queue. So, I am expecting better perf and more use cases (some might not = be applicable currently). Yep, I do understand that we can skip sync logic for ST case. Ok, if we do have multiple use-cases it might be plausible to have a separa= te API for it. >=20 > [1] https://mails.dpdk.org/archives/dev/2023-August/275003.html >=20 > > > > > > > > Signed-off-by: Honnappa Nagarahalli > > > --- > > > v1: > > > 1) The code is very prelimnary and is not even compiled > > > 2) This is intended to show the APIs and some thoughts on > > > implementation > > > 3) More APIs and the rest of the implementation will come in subseque= nt > > > versions > > > > > > lib/st_ring/rte_st_ring.h | 567 > > > ++++++++++++++++++++++++++++++++++++++ > > > 1 file changed, 567 insertions(+) > > > create mode 100644 lib/st_ring/rte_st_ring.h > > > > > > diff --git a/lib/st_ring/rte_st_ring.h b/lib/st_ring/rte_st_ring.h ne= w > > > file mode 100644 index 0000000000..8cb8832591 > > > --- /dev/null > > > +++ b/lib/st_ring/rte_st_ring.h > > > @@ -0,0 +1,567 @@ > > > +/* SPDX-License-Identifier: BSD-3-Clause > > > + * Copyright(c) 2023 Arm Limited > > > + */ > > > + > > > +#ifndef _RTE_ST_RING_H_ > > > +#define _RTE_ST_RING_H_ > > > + > > > +/** > > > + * @file > > > + * RTE Signle Thread Ring (ST Ring) > > > + * > > > + * The ST Ring is a fixed-size queue intended to be accessed > > > + * by one thread at a time. It does not provide concurrent access to > > > + * multiple threads. If there are multiple threads accessing the ST > > > +ring, > > > + * then the threads have to use locks to protect the ring from > > > + * getting corrupted. > > > + * > > > + * - FIFO (First In First Out) > > > + * - Maximum size is fixed; the pointers are stored in a table. > > > + * - Consumer and producer part of same thread. > > > + * - Multi-thread producers and consumers need locking. > > > + * - Single/Bulk/burst dequeue at Tail or Head > > > + * - Single/Bulk/burst enqueue at Head or Tail > > > + * > > > + */ > > > + > > > +#ifdef __cplusplus > > > +extern "C" { > > > +#endif > > > + > > > +#include > > > +#include > > > + > > > +/** > > > + * Calculate the memory size needed for a ST ring > > > + * > > > + * This function returns the number of bytes needed for a ST ring, > > > +given > > > + * the number of elements in it. This value is the sum of the size o= f > > > + * the structure rte_st_ring and the size of the memory needed by th= e > > > + * elements. The value is aligned to a cache line size. > > > + * > > > + * @param count > > > + * The number of elements in the ring (must be a power of 2). > > > + * @return > > > + * - The memory size needed for the ST ring on success. > > > + * - -EINVAL if count is not a power of 2. > > > + */ > > > +ssize_t rte_st_ring_get_memsize(unsigned int count); > > > + > > > +/** > > > + * Initialize a ST ring structure. > > > + * > > > + * Initialize a ST ring structure in memory pointed by "r". The size > > > +of the > > > + * memory area must be large enough to store the ring structure and > > > +the > > > + * object table. It is advised to use rte_st_ring_get_memsize() to > > > +get the > > > + * appropriate size. > > > + * > > > + * The ST ring size is set to *count*, which must be a power of two. > > > + * The real usable ring size is *count-1* instead of *count* to > > > + * differentiate a full ring from an empty ring. > > > + * > > > + * The ring is not added in RTE_TAILQ_ST_RING global list. Indeed, > > > +the > > > + * memory given by the caller may not be shareable among dpdk > > > + * processes. > > > + * > > > + * @param r > > > + * The pointer to the ring structure followed by the elements tabl= e. > > > + * @param name > > > + * The name of the ring. > > > + * @param count > > > + * The number of elements in the ring (must be a power of 2, > > > + * unless RTE_ST_RING_F_EXACT_SZ is set in flags). > > > + * @param flags > > > + * An OR of the following: > > > + * - RTE_ST_RING_F_EXACT_SZ: If this flag is set, the ring will ho= ld > > > + * exactly the requested number of entries, and the requested si= ze > > > + * will be rounded up to the next power of two, but the usable s= pace > > > + * will be exactly that requested. Worst case, if a power-of-2 s= ize is > > > + * requested, half the ring space will be wasted. > > > + * Without this flag set, the ring size requested must be a powe= r of 2, > > > + * and the usable space will be that size - 1. > > > + * @return > > > + * 0 on success, or a negative value on error. > > > + */ > > > +int rte_st_ring_init(struct rte_st_ring *r, const char *name, > > > + unsigned int count, unsigned int flags); > > > + > > > +/** > > > + * Create a new ST ring named *name* in memory. > > > + * > > > + * This function uses ``memzone_reserve()`` to allocate memory. Then > > > +it > > > + * calls rte_st_ring_init() to initialize an empty ring. > > > + * > > > + * The new ring size is set to *count*, which must be a power of two= . > > > + * The real usable ring size is *count-1* instead of *count* to > > > + * differentiate a full ring from an empty ring. > > > + * > > > + * The ring is added in RTE_TAILQ_ST_RING list. > > > + * > > > + * @param name > > > + * The name of the ring. > > > + * @param count > > > + * The size of the ring (must be a power of 2, > > > + * unless RTE_ST_RING_F_EXACT_SZ is set in flags). > > > + * @param socket_id > > > + * The *socket_id* argument is the socket identifier in case of > > > + * NUMA. The value can be *SOCKET_ID_ANY* if there is no NUMA > > > + * constraint for the reserved zone. > > > + * @param flags > > > + * - RTE_ST_RING_F_EXACT_SZ: If this flag is set, the ring will ho= ld exactly > > the > > > + * requested number of entries, and the requested size will be r= ounded up > > > + * to the next power of two, but the usable space will be exactl= y that > > > + * requested. Worst case, if a power-of-2 size is requested, hal= f the > > > + * ring space will be wasted. > > > + * Without this flag set, the ring size requested must be a powe= r of 2, > > > + * and the usable space will be that size - 1. > > > + * @return > > > + * On success, the pointer to the new allocated ring. NULL on erro= r with > > > + * rte_errno set appropriately. Possible errno values include: > > > + * - E_RTE_NO_CONFIG - function could not get pointer to rte_conf= ig > > structure > > > + * - EINVAL - count provided is not a power of 2 > > > + * - ENOSPC - the maximum number of memzones has already been > > allocated > > > + * - EEXIST - a memzone with the same name already exists > > > + * - ENOMEM - no appropriate memory area found in which to create > > memzone > > > + */ > > > +struct rte_st_ring *rte_st_ring_create(const char *name, unsigned in= t count, > > > + int socket_id, unsigned int flags); > > > + > > > +/** > > > + * De-allocate all memory used by the ring. > > > + * > > > + * @param r > > > + * Ring to free. > > > + * If NULL then, the function does nothing. > > > + */ > > > +void rte_st_ring_free(struct rte_st_ring *r); > > > + > > > +/** > > > + * Dump the status of the ring to a file. > > > + * > > > + * @param f > > > + * A pointer to a file for output > > > + * @param r > > > + * A pointer to the ring structure. > > > + */ > > > +void rte_st_ring_dump(FILE *f, const struct rte_st_ring *r); > > > + > > > +/** > > > + * Enqueue fixed number of objects on a ST ring. > > > + * > > > + * This function copies the objects at the head of the ring and > > > + * moves the head index. > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @param obj_table > > > + * A pointer to a table of void * pointers (objects). > > > + * @param n > > > + * The number of objects to add in the ring from the obj_table. > > > + * @param free_space > > > + * if non-NULL, returns the amount of space in the ring after the > > > + * enqueue operation has finished. > > > + * @return > > > + * The number of objects enqueued, either 0 or n > > > + */ > > > +static __rte_always_inline unsigned int > > > +rte_st_ring_enqueue_bulk(struct rte_st_ring *r, void * const *obj_ta= ble, > > > + unsigned int n, unsigned int *free_space) { > > > + return rte_st_ring_enqueue_bulk_elem(r, obj_table, sizeof(void *), > > > + n, free_space); > > > +} > > > + > > > +/** > > > + * Enqueue upto a maximum number of objects on a ST ring. > > > + * > > > + * This function copies the objects at the head of the ring and > > > + * moves the head index. > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @param obj_table > > > + * A pointer to a table of void * pointers (objects). > > > + * @param n > > > + * The number of objects to add in the ring from the obj_table. > > > + * @param free_space > > > + * if non-NULL, returns the amount of space in the ring after the > > > + * enqueue operation has finished. > > > + * @return > > > + * - n: Actual number of objects enqueued. > > > + */ > > > +static __rte_always_inline unsigned int > > > +rte_st_ring_enqueue_burst(struct rte_st_ring *r, void * const *obj_t= able, > > > + unsigned int n, unsigned int *free_space) { > > > + return rte_st_ring_enqueue_burst_elem(r, obj_table, sizeof(void *), > > > + n, free_space); > > > +} > > > + > > > +/** > > > + * Enqueue one object on a ST ring. > > > + * > > > + * This function copies one object at the head of the ring and > > > + * moves the head index. > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @param obj > > > + * A pointer to the object to be added. > > > + * @return > > > + * - 0: Success; objects enqueued. > > > + * - -ENOBUFS: Not enough room in the ring to enqueue; no object i= s > > enqueued. > > > + */ > > > +static __rte_always_inline int > > > +rte_st_ring_enqueue(struct rte_st_ring *r, void *obj) { > > > + return rte_st_ring_enqueue_elem(r, &obj, sizeof(void *)); } > > > + > > > +/** > > > + * Enqueue fixed number of objects on a ST ring at the tail. > > > + * > > > + * This function copies the objects at the tail of the ring and > > > + * moves the tail index (backwards). > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @param obj_table > > > + * A pointer to a table of void * pointers (objects). > > > + * @param n > > > + * The number of objects to add in the ring from the obj_table. > > > + * @param free_space > > > + * if non-NULL, returns the amount of space in the ring after the > > > + * enqueue operation has finished. > > > + * @return > > > + * The number of objects enqueued, either 0 or n > > > + */ > > > +static __rte_always_inline unsigned int > > > +rte_st_ring_enqueue_at_tail_bulk(struct rte_st_ring *r, > > > + void * const *obj_table, unsigned int n, > > > + unsigned int *free_space) > > > +{ > > > + return rte_st_ring_enqueue_at_tail_bulk_elem(r, obj_table, > > > + sizeof(void *), n, free_space); > > > +} > > > + > > > +/** > > > + * Enqueue upto a maximum number of objects on a ST ring at the tail= . > > > + * > > > + * This function copies the objects at the tail of the ring and > > > + * moves the tail index (backwards). > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @param obj_table > > > + * A pointer to a table of void * pointers (objects). > > > + * @param n > > > + * The number of objects to add in the ring from the obj_table. > > > + * @param free_space > > > + * if non-NULL, returns the amount of space in the ring after the > > > + * enqueue operation has finished. > > > + * @return > > > + * - n: Actual number of objects enqueued. > > > + */ > > > +static __rte_always_inline unsigned int > > > +rte_st_ring_enqueue_at_tail_burst(struct rte_st_ring *r, > > > + void * const *obj_table, unsigned int n, > > > + unsigned int *free_space) > > > +{ > > > + return rte_st_ring_enqueue_at_tail_burst_elem(r, obj_table, > > > + sizeof(void *), n, free_space); > > > +} > > > + > > > +/** > > > + * Enqueue one object on a ST ring at tail. > > > + * > > > + * This function copies one object at the tail of the ring and > > > + * moves the tail index (backwards). > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @param obj > > > + * A pointer to the object to be added. > > > + * @return > > > + * - 0: Success; objects enqueued. > > > + * - -ENOBUFS: Not enough room in the ring to enqueue; no object i= s > > enqueued. > > > + */ > > > +static __rte_always_inline int > > > +rte_st_ring_enqueue_at_tail(struct rte_st_ring *r, void *obj) { > > > + return rte_st_ring_enqueue_at_tail_elem(r, &obj, sizeof(void *)); } > > > + > > > +/** > > > + * Dequeue a fixed number of objects from a ST ring. > > > + * > > > + * This function copies the objects from the tail of the ring and > > > + * moves the tail index. > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @param obj_table > > > + * A pointer to a table of void * pointers (objects) that will be = filled. > > > + * @param n > > > + * The number of objects to dequeue from the ring to the obj_table= . > > > + * @param available > > > + * If non-NULL, returns the number of remaining ring entries after= the > > > + * dequeue has finished. > > > + * @return > > > + * The number of objects dequeued, either 0 or n > > > + */ > > > +static __rte_always_inline unsigned int > > > +rte_st_ring_dequeue_bulk(struct rte_st_ring *r, void **obj_table, un= signed > > int n, > > > + unsigned int *available) > > > +{ > > > + return rte_st_ring_dequeue_bulk_elem(r, obj_table, sizeof(void *), > > > + n, available); > > > +} > > > + > > > +/** > > > + * Dequeue upto a maximum number of objects from a ST ring. > > > + * > > > + * This function copies the objects from the tail of the ring and > > > + * moves the tail index. > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @param obj_table > > > + * A pointer to a table of void * pointers (objects) that will be = filled. > > > + * @param n > > > + * The number of objects to dequeue from the ring to the obj_table= . > > > + * @param available > > > + * If non-NULL, returns the number of remaining ring entries after= the > > > + * dequeue has finished. > > > + * @return > > > + * - Number of objects dequeued > > > + */ > > > +static __rte_always_inline unsigned int > > > +rte_st_ring_dequeue_burst(struct rte_st_ring *r, void **obj_table, > > > + unsigned int n, unsigned int *available) { > > > + return rte_st_ring_dequeue_burst_elem(r, obj_table, sizeof(void *), > > > + n, available); > > > +} > > > + > > > +/** > > > + * Dequeue one object from a ST ring. > > > + * > > > + * This function copies one object from the tail of the ring and > > > + * moves the tail index. > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @param obj_p > > > + * A pointer to a void * pointer (object) that will be filled. > > > + * @return > > > + * - 0: Success, objects dequeued. > > > + * - -ENOENT: Not enough entries in the ring to dequeue, no object= is > > > + * dequeued. > > > + */ > > > +static __rte_always_inline int > > > +rte_st_ring_dequeue(struct rte_st_ring *r, void **obj_p) { > > > + return rte_st_ring_dequeue_elem(r, obj_p, sizeof(void *)); } > > > + > > > +/** > > > + * Dequeue a fixed number of objects from a ST ring from the head. > > > + * > > > + * This function copies the objects from the head of the ring and > > > + * moves the head index (backwards). > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @param obj_table > > > + * A pointer to a table of void * pointers (objects) that will be = filled. > > > + * @param n > > > + * The number of objects to dequeue from the ring to the obj_table= . > > > + * @param available > > > + * If non-NULL, returns the number of remaining ring entries after= the > > > + * dequeue has finished. > > > + * @return > > > + * The number of objects dequeued, either 0 or n > > > + */ > > > +static __rte_always_inline unsigned int > > > +rte_st_ring_dequeue_at_head_bulk(struct rte_st_ring *r, void **obj_t= able, > > unsigned int n, > > > + unsigned int *available) > > > +{ > > > + return rte_st_ring_dequeue_bulk_elem(r, obj_table, sizeof(void *), > > > + n, available); > > > +} > > > + > > > +/** > > > + * Dequeue upto a maximum number of objects from a ST ring from the > > head. > > > + * > > > + * This function copies the objects from the head of the ring and > > > + * moves the head index (backwards). > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @param obj_table > > > + * A pointer to a table of void * pointers (objects) that will be = filled. > > > + * @param n > > > + * The number of objects to dequeue from the ring to the obj_table= . > > > + * @param available > > > + * If non-NULL, returns the number of remaining ring entries after= the > > > + * dequeue has finished. > > > + * @return > > > + * - Number of objects dequeued > > > + */ > > > +static __rte_always_inline unsigned int > > > +rte_st_ring_dequeue_at_head_burst(struct rte_st_ring *r, void > > **obj_table, > > > + unsigned int n, unsigned int *available) { > > > + return rte_st_ring_dequeue_burst_elem(r, obj_table, sizeof(void *), > > > + n, available); > > > +} > > > + > > > +/** > > > + * Dequeue one object from a ST ring from the head. > > > + * > > > + * This function copies the objects from the head of the ring and > > > + * moves the head index (backwards). > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @param obj_p > > > + * A pointer to a void * pointer (object) that will be filled. > > > + * @return > > > + * - 0: Success, objects dequeued. > > > + * - -ENOENT: Not enough entries in the ring to dequeue, no object= is > > > + * dequeued. > > > + */ > > > +static __rte_always_inline int > > > +rte_st_ring_at_head_dequeue(struct rte_st_ring *r, void **obj_p) { > > > + return rte_st_ring_dequeue_elem(r, obj_p, sizeof(void *)); } > > > + > > > +/** > > > + * Flush a ST ring. > > > + * > > > + * This function flush all the elements in a ST ring > > > + * > > > + * @warning > > > + * Make sure the ring is not in use while calling this function. > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + */ > > > +void > > > +rte_st_ring_reset(struct rte_st_ring *r); > > > + > > > +/** > > > + * Return the number of entries in a ST ring. > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @return > > > + * The number of entries in the ring. > > > + */ > > > +static inline unsigned int > > > +rte_st_ring_count(const struct rte_st_ring *r) { > > > + uint32_t count =3D (r->head - r->tail) & r->mask; > > > + return count; > > > +} > > > + > > > +/** > > > + * Return the number of free entries in a ST ring. > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @return > > > + * The number of free entries in the ring. > > > + */ > > > +static inline unsigned int > > > +rte_st_ring_free_count(const struct rte_st_ring *r) { > > > + return r->capacity - rte_st_ring_count(r); } > > > + > > > +/** > > > + * Test if a ST ring is full. > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @return > > > + * - 1: The ring is full. > > > + * - 0: The ring is not full. > > > + */ > > > +static inline int > > > +rte_st_ring_full(const struct rte_st_ring *r) { > > > + return rte_st_ring_free_count(r) =3D=3D 0; } > > > + > > > +/** > > > + * Test if a ST ring is empty. > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @return > > > + * - 1: The ring is empty. > > > + * - 0: The ring is not empty. > > > + */ > > > +static inline int > > > +rte_st_ring_empty(const struct rte_st_ring *r) { > > > + return r->tail =3D=3D r->head; > > > +} > > > + > > > +/** > > > + * Return the size of the ring. > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @return > > > + * The size of the data store used by the ring. > > > + * NOTE: this is not the same as the usable space in the ring. To = query that > > > + * use ``rte_st_ring_get_capacity()``. > > > + */ > > > +static inline unsigned int > > > +rte_st_ring_get_size(const struct rte_st_ring *r) { > > > + return r->size; > > > +} > > > + > > > +/** > > > + * Return the number of elements which can be stored in the ring. > > > + * > > > + * @param r > > > + * A pointer to the ring structure. > > > + * @return > > > + * The usable size of the ring. > > > + */ > > > +static inline unsigned int > > > +rte_st_ring_get_capacity(const struct rte_st_ring *r) { > > > + return r->capacity; > > > +} > > > + > > > +/** > > > + * Dump the status of all rings on the console > > > + * > > > + * @param f > > > + * A pointer to a file for output > > > + */ > > > +void rte_st_ring_list_dump(FILE *f); > > > + > > > +/** > > > + * Search a ST ring from its name > > > + * > > > + * @param name > > > + * The name of the ring. > > > + * @return > > > + * The pointer to the ring matching the name, or NULL if not found= , > > > + * with rte_errno set appropriately. Possible rte_errno values inc= lude: > > > + * - ENOENT - required entry not available to return. > > > + */ > > > +struct rte_st_ring *rte_st_ring_lookup(const char *name); > > > + > > > +#ifdef __cplusplus > > > +} > > > +#endif > > > + > > > +#endif /* _RTE_ST_RING_H_ */ > > > -- > > > 2.25.1 > > >