From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id A1988A04BB; Tue, 6 Oct 2020 15:29:35 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 8B02A1B3D9; Tue, 6 Oct 2020 15:29:17 +0200 (CEST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by dpdk.org (Postfix) with ESMTP id AD27B2C6E for ; Tue, 6 Oct 2020 15:29:16 +0200 (CEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2EE7A1476; Tue, 6 Oct 2020 06:29:15 -0700 (PDT) Received: from qc2400f-1.austin.arm.com (qc2400f-1.austin.arm.com [10.118.12.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 16E6C3F71F; Tue, 6 Oct 2020 06:29:15 -0700 (PDT) From: Honnappa Nagarahalli To: dev@dpdk.org, honnappa.nagarahalli@arm.com, konstantin.ananyev@intel.com Cc: olivier.matz@6wind.com, david.marchand@redhat.com, nd@arm.com Date: Tue, 6 Oct 2020 08:29:05 -0500 Message-Id: <20201006132905.46205-2-honnappa.nagarahalli@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201006132905.46205-1-honnappa.nagarahalli@arm.com> References: <20200224203931.21256-1-honnappa.nagarahalli@arm.com> <20201006132905.46205-1-honnappa.nagarahalli@arm.com> Subject: [dpdk-dev] [RFC v2 1/1] lib/ring: add scatter gather APIs X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Add scatter gather APIs to avoid intermediate memcpy. Use cases that involve copying large amount of data to/from the ring can benefit from these APIs. Signed-off-by: Honnappa Nagarahalli --- lib/librte_ring/meson.build | 3 +- lib/librte_ring/rte_ring_elem.h | 1 + lib/librte_ring/rte_ring_peek_sg.h | 552 +++++++++++++++++++++++++++++ 3 files changed, 555 insertions(+), 1 deletion(-) create mode 100644 lib/librte_ring/rte_ring_peek_sg.h diff --git a/lib/librte_ring/meson.build b/lib/librte_ring/meson.build index 31c0b4649..377694713 100644 --- a/lib/librte_ring/meson.build +++ b/lib/librte_ring/meson.build @@ -12,4 +12,5 @@ headers = files('rte_ring.h', 'rte_ring_peek.h', 'rte_ring_peek_c11_mem.h', 'rte_ring_rts.h', - 'rte_ring_rts_c11_mem.h') + 'rte_ring_rts_c11_mem.h', + 'rte_ring_peek_sg.h') diff --git a/lib/librte_ring/rte_ring_elem.h b/lib/librte_ring/rte_ring_elem.h index 938b398fc..7d3933f15 100644 --- a/lib/librte_ring/rte_ring_elem.h +++ b/lib/librte_ring/rte_ring_elem.h @@ -1079,6 +1079,7 @@ rte_ring_dequeue_burst_elem(struct rte_ring *r, void *obj_table, #ifdef ALLOW_EXPERIMENTAL_API #include +#include #endif #include diff --git a/lib/librte_ring/rte_ring_peek_sg.h b/lib/librte_ring/rte_ring_peek_sg.h new file mode 100644 index 000000000..97d5764a6 --- /dev/null +++ b/lib/librte_ring/rte_ring_peek_sg.h @@ -0,0 +1,552 @@ +/* SPDX-License-Identifier: BSD-3-Clause + * + * Copyright (c) 2020 Arm + * Copyright (c) 2007-2009 Kip Macy kmacy@freebsd.org + * All rights reserved. + * Derived from FreeBSD's bufring.h + * Used as BSD-3 Licensed with permission from Kip Macy. + */ + +#ifndef _RTE_RING_PEEK_SG_H_ +#define _RTE_RING_PEEK_SG_H_ + +/** + * @file + * @b EXPERIMENTAL: this API may change without prior notice + * It is not recommended to include this file directly. + * Please include instead. + * + * Ring Peek Scatter Gather APIs + * Introduction of rte_ring with scatter gather serialized producer/consumer + * (HTS sync mode) makes it possible to split public enqueue/dequeue API + * into 3 phases: + * - enqueue/dequeue start + * - copy data to/from the ring + * - enqueue/dequeue finish + * Along with the advantages of the peek APIs, these APIs provide the ability + * to avoid copying of the data to temporary area. + * + * Note that right now this new API is available only for two sync modes: + * 1) Single Producer/Single Consumer (RTE_RING_SYNC_ST) + * 2) Serialized Producer/Serialized Consumer (RTE_RING_SYNC_MT_HTS). + * It is a user responsibility to create/init ring with appropriate sync + * modes selected. + * + * Example usage: + * // read 1 elem from the ring: + * n = rte_ring_enqueue_sg_bulk_start(ring, 32, &sgd, NULL); + * if (n != 0) { + * //Copy objects in the ring + * memcpy (sgd->ptr1, obj, sgd->n1 * sizeof(uintptr_t)); + * if (n != sgd->n1) + * //Second memcpy because of wrapround + * n2 = n - sgd->n1; + * memcpy (sgd->ptr2, obj[n2], n2 * sizeof(uintptr_t)); + * rte_ring_dequeue_sg_finish(ring, n); + * } + * + * Note that between _start_ and _finish_ none other thread can proceed + * with enqueue(/dequeue) operation till _finish_ completes. + */ + +#ifdef __cplusplus +extern "C" { +#endif + +#include + +/* Rock that needs to be passed between reserve and commit APIs */ +struct rte_ring_sg_data { + /* Pointer to the first space in the ring */ + void **ptr1; + /* Pointer to the second space in the ring if there is wrap-around */ + void **ptr2; + /* Number of elements in the first pointer. If this is equal to + * the number of elements requested, then ptr2 is NULL. + * Otherwise, subtracting n1 from number of elements requested + * will give the number of elements available at ptr2. + */ + unsigned int n1; +}; + +static __rte_always_inline void +__rte_ring_get_elem_addr_64(struct rte_ring *r, uint32_t head, + uint32_t num, void **dst1, uint32_t *n1, void **dst2) +{ + uint32_t idx = head & r->mask; + uint64_t *ring = (uint64_t *)&r[1]; + + *dst1 = ring + idx; + *n1 = num; + + if (idx + num > r->size) { + *n1 = num - (r->size - idx - 1); + *dst2 = ring; + } +} + +static __rte_always_inline void +__rte_ring_get_elem_addr_128(struct rte_ring *r, uint32_t head, + uint32_t num, void **dst1, uint32_t *n1, void **dst2) +{ + uint32_t idx = head & r->mask; + rte_int128_t *ring = (rte_int128_t *)&r[1]; + + *dst1 = ring + idx; + *n1 = num; + + if (idx + num > r->size) { + *n1 = num - (r->size - idx - 1); + *dst2 = ring; + } +} + +static __rte_always_inline void +__rte_ring_get_elem_addr(struct rte_ring *r, uint32_t head, + uint32_t esize, uint32_t num, void **dst1, uint32_t *n1, void **dst2) +{ + if (esize == 8) + __rte_ring_get_elem_addr_64(r, head, + num, dst1, n1, dst2); + else if (esize == 16) + __rte_ring_get_elem_addr_128(r, head, + num, dst1, n1, dst2); + else { + uint32_t idx, scale, nr_idx; + uint32_t *ring = (uint32_t *)&r[1]; + + /* Normalize to uint32_t */ + scale = esize / sizeof(uint32_t); + idx = head & r->mask; + nr_idx = idx * scale; + + *dst1 = ring + nr_idx; + *n1 = num; + + if (idx + num > r->size) { + *n1 = num - (r->size - idx - 1); + *dst2 = ring; + } + } +} + +/** + * @internal This function moves prod head value. + */ +static __rte_always_inline unsigned int +__rte_ring_do_enqueue_sg_elem_start(struct rte_ring *r, unsigned int esize, + uint32_t n, enum rte_ring_queue_behavior behavior, + struct rte_ring_sg_data *sgd, unsigned int *free_space) +{ + uint32_t free, head, next; + + switch (r->prod.sync_type) { + case RTE_RING_SYNC_ST: + n = __rte_ring_move_prod_head(r, RTE_RING_SYNC_ST, n, + behavior, &head, &next, &free); + __rte_ring_get_elem_addr(r, head, esize, n, (void **)&sgd->ptr1, + &sgd->n1, (void **)&sgd->ptr2); + break; + case RTE_RING_SYNC_MT_HTS: + n = __rte_ring_hts_move_prod_head(r, n, behavior, &head, &free); + __rte_ring_get_elem_addr(r, head, esize, n, (void **)&sgd->ptr1, + &sgd->n1, (void **)&sgd->ptr2); + break; + case RTE_RING_SYNC_MT: + case RTE_RING_SYNC_MT_RTS: + default: + /* unsupported mode, shouldn't be here */ + RTE_ASSERT(0); + n = 0; + free = 0; + } + + if (free_space != NULL) + *free_space = free - n; + return n; +} + +/** + * Start to enqueue several objects on the ring. + * Note that no actual objects are put in the queue by this function, + * it just reserves space for the user on the ring. + * User has to copy objects into the queue using the returned pointers. + * User should call rte_ring_enqueue_sg_bulk_elem_finish to complete the + * enqueue operation. + * + * @param r + * A pointer to the ring structure. + * @param esize + * The size of ring element, in bytes. It must be a multiple of 4. + * @param n + * The number of objects to add in the ring. + * @param sgd + * The scatter-gather data containing pointers for copying data. + * @param free_space + * if non-NULL, returns the amount of space in the ring after the + * reservation operation has finished. + * @return + * The number of objects that can be enqueued, either 0 or n + */ +__rte_experimental +static __rte_always_inline unsigned int +rte_ring_enqueue_sg_bulk_elem_start(struct rte_ring *r, unsigned int esize, + unsigned int n, struct rte_ring_sg_data *sgd, unsigned int *free_space) +{ + return __rte_ring_do_enqueue_sg_elem_start(r, esize, n, + RTE_RING_QUEUE_FIXED, sgd, free_space); +} + +/** + * Start to enqueue several pointers to objects on the ring. + * Note that no actual pointers are put in the queue by this function, + * it just reserves space for the user on the ring. + * User has to copy pointers to objects into the queue using the + * returned pointers. + * User should call rte_ring_enqueue_sg_bulk_finish to complete the + * enqueue operation. + * + * @param r + * A pointer to the ring structure. + * @param n + * The number of objects to add in the ring. + * @param sgd + * The scatter-gather data containing pointers for copying data. + * @param free_space + * if non-NULL, returns the amount of space in the ring after the + * reservation operation has finished. + * @return + * The number of objects that can be enqueued, either 0 or n + */ +__rte_experimental +static __rte_always_inline unsigned int +rte_ring_enqueue_sg_bulk_start(struct rte_ring *r, unsigned int n, + struct rte_ring_sg_data *sgd, unsigned int *free_space) +{ + return rte_ring_enqueue_sg_bulk_elem_start(r, sizeof(uintptr_t), n, + sgd, free_space); +} +/** + * Start to enqueue several objects on the ring. + * Note that no actual objects are put in the queue by this function, + * it just reserves space for the user on the ring. + * User has to copy objects into the queue using the returned pointers. + * User should call rte_ring_enqueue_sg_bulk_elem_finish to complete the + * enqueue operation. + * + * @param r + * A pointer to the ring structure. + * @param esize + * The size of ring element, in bytes. It must be a multiple of 4. + * @param n + * The number of objects to add in the ring. + * @param sgd + * The scatter-gather data containing pointers for copying data. + * @param free_space + * if non-NULL, returns the amount of space in the ring after the + * reservation operation has finished. + * @return + * The number of objects that can be enqueued, either 0 or n + */ +__rte_experimental +static __rte_always_inline unsigned int +rte_ring_enqueue_sg_burst_elem_start(struct rte_ring *r, unsigned int esize, + unsigned int n, struct rte_ring_sg_data *sgd, unsigned int *free_space) +{ + return __rte_ring_do_enqueue_sg_elem_start(r, esize, n, + RTE_RING_QUEUE_VARIABLE, sgd, free_space); +} + +/** + * Start to enqueue several pointers to objects on the ring. + * Note that no actual pointers are put in the queue by this function, + * it just reserves space for the user on the ring. + * User has to copy pointers to objects into the queue using the + * returned pointers. + * User should call rte_ring_enqueue_sg_bulk_finish to complete the + * enqueue operation. + * + * @param r + * A pointer to the ring structure. + * @param n + * The number of objects to add in the ring. + * @param sgd + * The scatter-gather data containing pointers for copying data. + * @param free_space + * if non-NULL, returns the amount of space in the ring after the + * reservation operation has finished. + * @return + * The number of objects that can be enqueued, either 0 or n + */ +__rte_experimental +static __rte_always_inline unsigned int +rte_ring_enqueue_sg_burst_start(struct rte_ring *r, unsigned int n, + struct rte_ring_sg_data *sgd, unsigned int *free_space) +{ + return rte_ring_enqueue_sg_burst_elem_start(r, sizeof(uintptr_t), n, + sgd, free_space); +} + +/** + * Complete enqueuing several objects on the ring. + * Note that number of objects to enqueue should not exceed previous + * enqueue_start return value. + * + * @param r + * A pointer to the ring structure. + * @param n + * The number of objects to add to the ring. + */ +__rte_experimental +static __rte_always_inline void +rte_ring_enqueue_sg_elem_finish(struct rte_ring *r, unsigned int n) +{ + uint32_t tail; + + switch (r->prod.sync_type) { + case RTE_RING_SYNC_ST: + n = __rte_ring_st_get_tail(&r->prod, &tail, n); + __rte_ring_st_set_head_tail(&r->prod, tail, n, 1); + break; + case RTE_RING_SYNC_MT_HTS: + n = __rte_ring_hts_get_tail(&r->hts_prod, &tail, n); + __rte_ring_hts_set_head_tail(&r->hts_prod, tail, n, 1); + break; + case RTE_RING_SYNC_MT: + case RTE_RING_SYNC_MT_RTS: + default: + /* unsupported mode, shouldn't be here */ + RTE_ASSERT(0); + } +} + +/** + * Complete enqueuing several pointers to objects on the ring. + * Note that number of objects to enqueue should not exceed previous + * enqueue_start return value. + * + * @param r + * A pointer to the ring structure. + * @param n + * The number of pointers to objects to add to the ring. + */ +__rte_experimental +static __rte_always_inline void +rte_ring_enqueue_sg_finish(struct rte_ring *r, unsigned int n) +{ + rte_ring_enqueue_sg_elem_finish(r, n); +} + +/** + * @internal This function moves cons head value and copies up to *n* + * objects from the ring to the user provided obj_table. + */ +static __rte_always_inline unsigned int +__rte_ring_do_dequeue_sg_elem_start(struct rte_ring *r, + uint32_t esize, uint32_t n, enum rte_ring_queue_behavior behavior, + struct rte_ring_sg_data *sgd, unsigned int *available) +{ + uint32_t avail, head, next; + + switch (r->cons.sync_type) { + case RTE_RING_SYNC_ST: + n = __rte_ring_move_cons_head(r, RTE_RING_SYNC_ST, n, + behavior, &head, &next, &avail); + __rte_ring_get_elem_addr(r, head, esize, n, + sgd->ptr1, &sgd->n1, sgd->ptr2); + break; + case RTE_RING_SYNC_MT_HTS: + n = __rte_ring_hts_move_cons_head(r, n, behavior, + &head, &avail); + __rte_ring_get_elem_addr(r, head, esize, n, + sgd->ptr1, &sgd->n1, sgd->ptr2); + break; + case RTE_RING_SYNC_MT: + case RTE_RING_SYNC_MT_RTS: + default: + /* unsupported mode, shouldn't be here */ + RTE_ASSERT(0); + n = 0; + avail = 0; + } + + if (available != NULL) + *available = avail - n; + return n; +} + +/** + * Start to dequeue several objects from the ring. + * Note that no actual objects are copied from the queue by this function. + * User has to copy objects from the queue using the returned pointers. + * User should call rte_ring_dequeue_sg_bulk_elem_finish to complete the + * dequeue operation. + * + * @param r + * A pointer to the ring structure. + * @param esize + * The size of ring element, in bytes. It must be a multiple of 4. + * @param n + * The number of objects to remove from the ring. + * @param sgd + * The scatter-gather data containing pointers for copying data. + * @param available + * If non-NULL, returns the number of remaining ring entries after the + * dequeue has finished. + * @return + * The number of objects that can be dequeued, either 0 or n + */ +__rte_experimental +static __rte_always_inline unsigned int +rte_ring_dequeue_sg_bulk_elem_start(struct rte_ring *r, unsigned int esize, + unsigned int n, struct rte_ring_sg_data *sgd, unsigned int *available) +{ + return __rte_ring_do_dequeue_sg_elem_start(r, esize, n, + RTE_RING_QUEUE_FIXED, sgd, available); +} + +/** + * Start to dequeue several pointers to objects from the ring. + * Note that no actual pointers are removed from the queue by this function. + * User has to copy pointers to objects from the queue using the + * returned pointers. + * User should call rte_ring_dequeue_sg_bulk_finish to complete the + * dequeue operation. + * + * @param r + * A pointer to the ring structure. + * @param n + * The number of objects to remove from the ring. + * @param sgd + * The scatter-gather data containing pointers for copying data. + * @param available + * If non-NULL, returns the number of remaining ring entries after the + * dequeue has finished. + * @return + * The number of objects that can be dequeued, either 0 or n + */ +__rte_experimental +static __rte_always_inline unsigned int +rte_ring_dequeue_sg_bulk_start(struct rte_ring *r, unsigned int n, + struct rte_ring_sg_data *sgd, unsigned int *available) +{ + return rte_ring_dequeue_sg_bulk_elem_start(r, sizeof(uintptr_t), + n, sgd, available); +} + +/** + * Start to dequeue several objects from the ring. + * Note that no actual objects are copied from the queue by this function. + * User has to copy objects from the queue using the returned pointers. + * User should call rte_ring_dequeue_sg_burst_elem_finish to complete the + * dequeue operation. + * + * @param r + * A pointer to the ring structure. + * @param esize + * The size of ring element, in bytes. It must be a multiple of 4. + * This must be the same value used while creating the ring. Otherwise + * the results are undefined. + * @param n + * The number of objects to dequeue from the ring. + * @param sgd + * The scatter-gather data containing pointers for copying data. + * @param available + * If non-NULL, returns the number of remaining ring entries after the + * dequeue has finished. + * @return + * The number of objects that can be dequeued, either 0 or n + */ +__rte_experimental +static __rte_always_inline unsigned int +rte_ring_dequeue_sg_burst_elem_start(struct rte_ring *r, unsigned int esize, + unsigned int n, struct rte_ring_sg_data *sgd, unsigned int *available) +{ + return __rte_ring_do_dequeue_sg_elem_start(r, esize, n, + RTE_RING_QUEUE_VARIABLE, sgd, available); +} + +/** + * Start to dequeue several pointers to objects from the ring. + * Note that no actual pointers are removed from the queue by this function. + * User has to copy pointers to objects from the queue using the + * returned pointers. + * User should call rte_ring_dequeue_sg_burst_finish to complete the + * dequeue operation. + * + * @param r + * A pointer to the ring structure. + * @param n + * The number of objects to remove from the ring. + * @param sgd + * The scatter-gather data containing pointers for copying data. + * @param available + * If non-NULL, returns the number of remaining ring entries after the + * dequeue has finished. + * @return + * The number of objects that can be dequeued, either 0 or n + */ +__rte_experimental +static __rte_always_inline unsigned int +rte_ring_dequeue_sg_burst_start(struct rte_ring *r, unsigned int n, + struct rte_ring_sg_data *sgd, unsigned int *available) +{ + return rte_ring_dequeue_sg_burst_elem_start(r, sizeof(uintptr_t), n, + sgd, available); +} + +/** + * Complete dequeuing several objects from the ring. + * Note that number of objects to dequeued should not exceed previous + * dequeue_start return value. + * + * @param r + * A pointer to the ring structure. + * @param n + * The number of objects to remove from the ring. + */ +__rte_experimental +static __rte_always_inline void +rte_ring_dequeue_sg_elem_finish(struct rte_ring *r, unsigned int n) +{ + uint32_t tail; + + switch (r->cons.sync_type) { + case RTE_RING_SYNC_ST: + n = __rte_ring_st_get_tail(&r->cons, &tail, n); + __rte_ring_st_set_head_tail(&r->cons, tail, n, 0); + break; + case RTE_RING_SYNC_MT_HTS: + n = __rte_ring_hts_get_tail(&r->hts_cons, &tail, n); + __rte_ring_hts_set_head_tail(&r->hts_cons, tail, n, 0); + break; + case RTE_RING_SYNC_MT: + case RTE_RING_SYNC_MT_RTS: + default: + /* unsupported mode, shouldn't be here */ + RTE_ASSERT(0); + } +} + +/** + * Complete dequeuing several objects from the ring. + * Note that number of objects to dequeued should not exceed previous + * dequeue_start return value. + * + * @param r + * A pointer to the ring structure. + * @param n + * The number of objects to remove from the ring. + */ +__rte_experimental +static __rte_always_inline void +rte_ring_dequeue_sg_finish(struct rte_ring *r, unsigned int n) +{ + rte_ring_dequeue_elem_finish(r, n); +} + +#ifdef __cplusplus +} +#endif + +#endif /* _RTE_RING_PEEK_SG_H_ */ -- 2.17.1