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Tue, 7 Apr 2020 17:39:21 +0000 Received: from BYAPR11MB2549.namprd11.prod.outlook.com ([fe80::141d:cf28:589e:5f49]) by BYAPR11MB2549.namprd11.prod.outlook.com ([fe80::141d:cf28:589e:5f49%4]) with mapi id 15.20.2878.018; Tue, 7 Apr 2020 17:39:21 +0000 From: "Ananyev, Konstantin" To: Honnappa Nagarahalli , "stephen@networkplumber.org" , "Medvedkin, Vladimir" CC: "dev@dpdk.org" , "ruifeng.wang@arm.com" , "dharmik.thakkar@arm.com" , "nd@arm.com" Thread-Topic: [PATCH v4 1/4] lib/rcu: add resource reclamation APIs Thread-Index: AQHWCeeyx2wQaIFUDkKfKuH/bhXgO6ht5FcA Date: Tue, 7 Apr 2020 17:39:20 +0000 Message-ID: References: <20191001062917.35578-1-honnappa.nagarahalli@arm.com> <20200403184142.7729-1-honnappa.nagarahalli@arm.com> <20200403184142.7729-2-honnappa.nagarahalli@arm.com> In-Reply-To: <20200403184142.7729-2-honnappa.nagarahalli@arm.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-reaction: no-action dlp-version: 11.2.0.6 authentication-results: spf=none (sender IP is ) smtp.mailfrom=konstantin.ananyev@intel.com; x-originating-ip: [192.198.151.181] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 1272495a-8e0c-476e-9738-08d7db1a9ae6 x-ms-traffictypediagnostic: BYAPR11MB2918: x-ld-processed: 46c98d88-e344-4ed4-8496-4ed7712e255d,ExtAddr x-ms-exchange-transport-forked: True x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:3968; x-forefront-prvs: 036614DD9C x-forefront-antispam-report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:BYAPR11MB2549.namprd11.prod.outlook.com; PTR:; CAT:NONE; SFTY:; SFS:(10019020)(376002)(136003)(346002)(396003)(366004)(39860400002)(2906002)(9686003)(81156014)(5660300002)(6506007)(81166006)(7696005)(52536014)(8676002)(55016002)(478600001)(6636002)(8936002)(186003)(30864003)(76116006)(71200400001)(26005)(66556008)(110136005)(86362001)(66946007)(64756008)(316002)(33656002)(54906003)(4326008)(66476007)(66446008)(60764002)(579004); DIR:OUT; SFP:1102; x-ms-exchange-senderadcheck: 1 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: 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 x-ms-exchange-antispam-messagedata: C6B2QsA4X5Ft4ab+7hj5QwKICcbljb48AzNjk0bE5qxQlpqJVkH4Kk90hTBNg80eolyEmyjp3meNVafoWuxmMlgbAkqrowbhkbjY/lsDBr/uzN+QCFmNIuP14jCrFqR5sfqqTImhPuO2j9mdnjJpzQ== Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-Network-Message-Id: 1272495a-8e0c-476e-9738-08d7db1a9ae6 X-MS-Exchange-CrossTenant-originalarrivaltime: 07 Apr 2020 17:39:20.8361 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: MMvOOzm0u7b+v8BJhV99CYqZIQysuv9RLYA+gOOetomIt1dgX9uWqylW5ozjU6FXIGf276Q9GA0ns/FCOLpQSzx7lzlhWhTXVcug++pjfRM= X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR11MB2918 X-OriginatorOrg: intel.com Subject: Re: [dpdk-dev] [PATCH v4 1/4] lib/rcu: add resource reclamation 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 resource reclamation APIs to make it simple for applications > and libraries to integrate rte_rcu library. Few nits, thoughts, please see below. Apart from that - LGTM. Acked-by: Konstantin Ananyev >=20 > Signed-off-by: Honnappa Nagarahalli > Reviewed-by: Ola Liljedhal > Reviewed-by: Ruifeng Wang > --- > lib/librte_rcu/Makefile | 2 +- > lib/librte_rcu/meson.build | 2 + > lib/librte_rcu/rcu_qsbr_pvt.h | 57 +++++++ > lib/librte_rcu/rte_rcu_qsbr.c | 243 ++++++++++++++++++++++++++++- > lib/librte_rcu/rte_rcu_qsbr.h | 188 ++++++++++++++++++++++ > lib/librte_rcu/rte_rcu_version.map | 4 + > lib/meson.build | 6 +- > 7 files changed, 498 insertions(+), 4 deletions(-) > create mode 100644 lib/librte_rcu/rcu_qsbr_pvt.h >=20 > diff --git a/lib/librte_rcu/Makefile b/lib/librte_rcu/Makefile > index c4bb28d77..95f8a57e2 100644 > --- a/lib/librte_rcu/Makefile > +++ b/lib/librte_rcu/Makefile > @@ -8,7 +8,7 @@ LIB =3D librte_rcu.a >=20 > CFLAGS +=3D -DALLOW_EXPERIMENTAL_API > CFLAGS +=3D $(WERROR_FLAGS) -I$(SRCDIR) -O3 > -LDLIBS +=3D -lrte_eal > +LDLIBS +=3D -lrte_eal -lrte_ring >=20 > EXPORT_MAP :=3D rte_rcu_version.map >=20 > diff --git a/lib/librte_rcu/meson.build b/lib/librte_rcu/meson.build > index 62920ba02..e280b29c1 100644 > --- a/lib/librte_rcu/meson.build > +++ b/lib/librte_rcu/meson.build > @@ -10,3 +10,5 @@ headers =3D files('rte_rcu_qsbr.h') > if cc.get_id() =3D=3D 'clang' and dpdk_conf.get('RTE_ARCH_64') =3D=3D fa= lse > ext_deps +=3D cc.find_library('atomic') > endif > + > +deps +=3D ['ring'] > diff --git a/lib/librte_rcu/rcu_qsbr_pvt.h b/lib/librte_rcu/rcu_qsbr_pvt.= h > new file mode 100644 > index 000000000..413f28587 > --- /dev/null > +++ b/lib/librte_rcu/rcu_qsbr_pvt.h > @@ -0,0 +1,57 @@ > +/* SPDX-License-Identifier: BSD-3-Clause > + * Copyright (c) 2019 Arm Limited > + */ > + > +#ifndef _RTE_RCU_QSBR_PVT_H_ > +#define _RTE_RCU_QSBR_PVT_H_ > + > +/** > + * This file is private to the RCU library. It should not be included > + * by the user of this library. > + */ > + > +#ifdef __cplusplus > +extern "C" { > +#endif > + > +#include > +#include > + > +#include "rte_rcu_qsbr.h" > + > +/* RTE defer queue structure. > + * This structure holds the defer queue. The defer queue is used to > + * hold the deleted entries from the data structure that are not > + * yet freed. > + */ > +struct rte_rcu_qsbr_dq { > + struct rte_rcu_qsbr *v; /**< RCU QSBR variable used by this queue.*/ > + struct rte_ring *r; /**< RCU QSBR defer queue. */ > + uint32_t size; > + /**< Number of elements in the defer queue */ > + uint32_t esize; > + /**< Size (in bytes) of data, including the token, stored on the > + * defer queue. > + */ > + uint32_t trigger_reclaim_limit; > + /**< Trigger automatic reclamation after the defer queue > + * has atleast these many resources waiting. > + */ > + uint32_t max_reclaim_size; > + /**< Reclaim at the max these many resources during auto > + * reclamation. > + */ > + rte_rcu_qsbr_free_resource_t free_fn; > + /**< Function to call to free the resource. */ > + void *p; > + /**< Pointer passed to the free function. Typically, this is the > + * pointer to the data structure to which the resource to free > + * belongs. > + */ > +}; > + > +#ifdef __cplusplus > +} > +#endif > + > +#endif /* _RTE_RCU_QSBR_PVT_H_ */ > diff --git a/lib/librte_rcu/rte_rcu_qsbr.c b/lib/librte_rcu/rte_rcu_qsbr.= c > index 2f3fad776..e8c1e386f 100644 > --- a/lib/librte_rcu/rte_rcu_qsbr.c > +++ b/lib/librte_rcu/rte_rcu_qsbr.c > @@ -1,6 +1,6 @@ > /* SPDX-License-Identifier: BSD-3-Clause > * > - * Copyright (c) 2018 Arm Limited > + * Copyright (c) 2018-2019 Arm Limited > */ >=20 > #include > @@ -18,8 +18,10 @@ > #include > #include > #include > +#include >=20 > #include "rte_rcu_qsbr.h" > +#include "rcu_qsbr_pvt.h" >=20 > /* Get the memory size of QSBR variable */ > size_t > @@ -270,6 +272,245 @@ rte_rcu_qsbr_dump(FILE *f, struct rte_rcu_qsbr *v) > return 0; > } >=20 > +/* Create a queue used to store the data structure elements that can > + * be freed later. This queue is referred to as 'defer queue'. > + */ > +struct rte_rcu_qsbr_dq * > +rte_rcu_qsbr_dq_create(const struct rte_rcu_qsbr_dq_parameters *params) > +{ > + struct rte_rcu_qsbr_dq *dq; > + uint32_t qs_fifo_size; > + unsigned int flags; > + > + if (params =3D=3D NULL || params->free_fn =3D=3D NULL || > + params->v =3D=3D NULL || params->name =3D=3D NULL || > + params->size =3D=3D 0 || params->esize =3D=3D 0 || > + (params->esize % 4 !=3D 0)) { > + rte_log(RTE_LOG_ERR, rte_rcu_log_type, > + "%s(): Invalid input parameter\n", __func__); > + rte_errno =3D EINVAL; > + > + return NULL; > + } > + /* If auto reclamation is configured, reclaim limit > + * should be a valid value. > + */ > + if ((params->trigger_reclaim_limit <=3D params->size) && > + (params->max_reclaim_size =3D=3D 0)) { > + rte_log(RTE_LOG_ERR, rte_rcu_log_type, > + "%s(): Invalid input parameter, size =3D %u, trigger_reclaim_limit = =3D %u, max_reclaim_size =3D %u\n", > + __func__, params->size, params->trigger_reclaim_limit, > + params->max_reclaim_size); > + rte_errno =3D EINVAL; > + > + return NULL; > + } > + > + dq =3D rte_zmalloc(NULL, sizeof(struct rte_rcu_qsbr_dq), > + RTE_CACHE_LINE_SIZE); > + if (dq =3D=3D NULL) { > + rte_errno =3D ENOMEM; > + > + return NULL; > + } > + > + /* Decide the flags for the ring. > + * If MT safety is requested, use RTS for ring enqueue as most > + * use cases involve dq-enqueue happening on the control plane. > + * Ring dequeue is always HTS due to the possibility of revert. > + */ > + flags =3D RING_F_MP_RTS_ENQ; > + if (params->flags & RTE_RCU_QSBR_DQ_MT_UNSAFE) > + flags =3D RING_F_SP_ENQ; > + flags |=3D RING_F_MC_HTS_DEQ; > + /* round up qs_fifo_size to next power of two that is not less than > + * max_size. > + */ > + qs_fifo_size =3D rte_align32pow2(params->size + 1); > + /* Add token size to ring element size */ > + dq->r =3D rte_ring_create_elem(params->name, > + __RTE_QSBR_TOKEN_SIZE + params->esize, > + qs_fifo_size, SOCKET_ID_ANY, flags); > + if (dq->r =3D=3D NULL) { > + rte_log(RTE_LOG_ERR, rte_rcu_log_type, > + "%s(): defer queue create failed\n", __func__); > + rte_free(dq); > + return NULL; > + } > + > + dq->v =3D params->v; > + dq->size =3D params->size; > + dq->esize =3D __RTE_QSBR_TOKEN_SIZE + params->esize; > + dq->trigger_reclaim_limit =3D params->trigger_reclaim_limit; > + dq->max_reclaim_size =3D params->max_reclaim_size; > + dq->free_fn =3D params->free_fn; > + dq->p =3D params->p; > + > + return dq; > +} > + > +/* Enqueue one resource to the defer queue to free after the grace > + * period is over. > + */ > +int rte_rcu_qsbr_dq_enqueue(struct rte_rcu_qsbr_dq *dq, void *e) > +{ > + uint64_t token; > + uint32_t cur_size, free_size; > + > + if (dq =3D=3D NULL || e =3D=3D NULL) { > + rte_log(RTE_LOG_ERR, rte_rcu_log_type, > + "%s(): Invalid input parameter\n", __func__); > + rte_errno =3D EINVAL; > + > + return 1; > + } > + > + /* Start the grace period */ > + token =3D rte_rcu_qsbr_start(dq->v); > + > + /* Reclaim resources if the queue is 1/8th full. This helps Comment about 1/8 is probably left from older version? As I understand now it is configurable parameter. > + * the queue from growing too large and allows time for reader > + * threads to report their quiescent state. > + */ > + cur_size =3D rte_ring_count(dq->r); > + if (cur_size > dq->trigger_reclaim_limit) { > + rte_log(RTE_LOG_INFO, rte_rcu_log_type, > + "%s(): Triggering reclamation\n", __func__); > + rte_rcu_qsbr_dq_reclaim(dq, dq->max_reclaim_size, NULL, NULL); > + } > + > + /* Check if there is space for atleast 1 resource */ > + free_size =3D rte_ring_free_count(dq->r); > + if (!free_size) { Is there any point to do this check at all? You are doing enqueue below and handle situation with not enough space in the ring anyway. > + rte_log(RTE_LOG_ERR, rte_rcu_log_type, > + "%s(): Defer queue is full\n", __func__); > + /* Note that the token generated above is not used. > + * Other than wasting tokens, it should not cause any > + * other issues. > + */ > + rte_log(RTE_LOG_INFO, rte_rcu_log_type, > + "%s(): Skipped enqueuing token =3D %"PRIu64"\n", > + __func__, token); > + > + rte_errno =3D ENOSPC; > + return 1; > + } > + > + /* Enqueue the token and resource. Generating the token > + * and enqueuing (token + resource) on the queue is not an > + * atomic operation. This might result in tokens enqueued > + * out of order on the queue. So, some tokens might wait > + * longer than they are required to be reclaimed. > + */ > + char data[dq->esize]; > + memcpy(data, &token, __RTE_QSBR_TOKEN_SIZE); > + memcpy(data + __RTE_QSBR_TOKEN_SIZE, e, > + dq->esize - __RTE_QSBR_TOKEN_SIZE); > + /* Check the status as enqueue might fail since the other thread > + * might have used up the freed space. > + * Enqueue uses the configured flags when the DQ was created. > + */ > + if (rte_ring_enqueue_elem(dq->r, data, dq->esize) !=3D 0) { > + rte_log(RTE_LOG_ERR, rte_rcu_log_type, > + "%s(): Enqueue failed\n", __func__); > + /* Note that the token generated above is not used. > + * Other than wasting tokens, it should not cause any > + * other issues. > + */ > + rte_log(RTE_LOG_INFO, rte_rcu_log_type, > + "%s(): Skipped enqueuing token =3D %"PRIu64"\n", > + __func__, token); > + > + rte_errno =3D ENOSPC; > + return 1; > + } Just as a thought: in theory if we'll use MP_HTS(/SP) ring we can avoid wasting RCU tokens: if (rte_ring_enqueue_elem_bulk_start(dq->r, 1, NULL) !=3D 0) { token =3D rte_rcu_qsbr_start(dq->v); memcpy(data, &token, __RTE_QSBR_TOKEN_SIZE); rte_ring_enqueue_elem_finish(dq->r, data, dq->esize, 1); } Though it might slowdown things if we'll have a lot of parallel dq_enqueue.=20 So not sure is it worth it or not. > + > + rte_log(RTE_LOG_INFO, rte_rcu_log_type, > + "%s(): Enqueued token =3D %"PRIu64"\n", __func__, token); > + > + return 0; > +} > + > +/* Reclaim resources from the defer queue. */ > +int > +rte_rcu_qsbr_dq_reclaim(struct rte_rcu_qsbr_dq *dq, unsigned int n, > + unsigned int *freed, unsigned int *pending) > +{ > + uint32_t cnt; > + uint64_t token; > + > + if (dq =3D=3D NULL || n =3D=3D 0) { > + rte_log(RTE_LOG_ERR, rte_rcu_log_type, > + "%s(): Invalid input parameter\n", __func__); > + rte_errno =3D EINVAL; > + > + return 1; > + } > + > + cnt =3D 0; > + > + char e[dq->esize]; > + /* Check reader threads quiescent state and reclaim resources */ > + while ((cnt < n) && > + (rte_ring_dequeue_bulk_elem_start(dq->r, e, > + dq->esize, 1, NULL) !=3D 0)) { Another thought - any point to use burst_elem_start() here to retrieve more then 1 elem in one go? Something like: char e[32][dq->size];=20 while ((cnt < n) { k =3D RTE_MAX(32, cnt - n); k =3D rte_ring_dequeue_burst_elem_start(dq->r, e, dq->esize, k, NULL); if (k =3D 0) break; for (i =3D 0; i !=3D k; i++) { memcpy(&token, e[i], sizeof(uint64_t)); if (rte_rcu_qsbr_check(dq->v, token, false) !=3D 1) break; } k =3D i; rte_ring_dequeue_elem_finish(dq->r, k); for (i =3D 0; i !=3D k; i++) dq->free_fn(dq->p, e[i] + __RTE_QSBR_TOKEN_SIZE); n +=3D k; if (k =3D=3D 0) break; ? Also if at enqueue we guarantee strict ordrer (via enqueue_start/enqueue_fi= nish), then here we probably can do _check_ from the last retrieved token here? In theory that might help to minimize number of checks. I.E. do: for (i =3D k; i-- !=3D0; ) { memcpy(&token, e[i], sizeof(uint64_t)); if (rte_rcu_qsbr_check(dq->v, token, false) !=3D 1) =20 break; } k =3D i + 1; ... > + memcpy(&token, e, sizeof(uint64_t)); > + > + /* Reclaim the resource */ > + if (rte_rcu_qsbr_check(dq->v, token, false) !=3D 1) { > + rte_ring_dequeue_finish(dq->r, 0); > + break; > + } > + rte_ring_dequeue_finish(dq->r, 1); > + > + rte_log(RTE_LOG_INFO, rte_rcu_log_type, > + "%s(): Reclaimed token =3D %"PRIu64"\n", > + __func__, *(uint64_t *)e); > + > + dq->free_fn(dq->p, e + __RTE_QSBR_TOKEN_SIZE); > + > + cnt++; > + } > + > + rte_log(RTE_LOG_INFO, rte_rcu_log_type, > + "%s(): Reclaimed %u resources\n", __func__, cnt); > + > + if (freed !=3D NULL) > + *freed =3D cnt; > + if (pending !=3D NULL) > + *pending =3D rte_ring_count(dq->r); > + > + return 0; > +} > + > +/* Delete a defer queue. */ > +int > +rte_rcu_qsbr_dq_delete(struct rte_rcu_qsbr_dq *dq) > +{ > + unsigned int pending; > + > + if (dq =3D=3D NULL) { > + rte_log(RTE_LOG_ERR, rte_rcu_log_type, > + "%s(): Invalid input parameter\n", __func__); > + rte_errno =3D EINVAL; > + > + return 1; > + } > + > + /* Reclaim all the resources */ > + rte_rcu_qsbr_dq_reclaim(dq, ~0, NULL, &pending); > + if (pending !=3D 0) { > + rte_errno =3D EAGAIN; > + > + return 1; > + } > + > + rte_ring_free(dq->r); > + rte_free(dq); > + > + return 0; > +} > + > int rte_rcu_log_type; >=20 > RTE_INIT(rte_rcu_register) > diff --git a/lib/librte_rcu/rte_rcu_qsbr.h b/lib/librte_rcu/rte_rcu_qsbr.= h > index 0b5585925..213f9b029 100644 > --- a/lib/librte_rcu/rte_rcu_qsbr.h > +++ b/lib/librte_rcu/rte_rcu_qsbr.h > @@ -34,6 +34,7 @@ extern "C" { > #include > #include > #include > +#include >=20 > extern int rte_rcu_log_type; >=20 > @@ -84,6 +85,7 @@ struct rte_rcu_qsbr_cnt { > #define __RTE_QSBR_CNT_THR_OFFLINE 0 > #define __RTE_QSBR_CNT_INIT 1 > #define __RTE_QSBR_CNT_MAX ((uint64_t)~0) > +#define __RTE_QSBR_TOKEN_SIZE sizeof(uint64_t) >=20 > /* RTE Quiescent State variable structure. > * This structure has two elements that vary in size based on the > @@ -114,6 +116,84 @@ struct rte_rcu_qsbr { > */ > } __rte_cache_aligned; >=20 > +/** > + * Call back function called to free the resources. > + * > + * @param p > + * Pointer provided while creating the defer queue > + * @param e > + * Pointer to the resource data stored on the defer queue > + * > + * @return > + * None > + */ > +typedef void (*rte_rcu_qsbr_free_resource_t)(void *p, void *e); > + > +#define RTE_RCU_QSBR_DQ_NAMESIZE RTE_RING_NAMESIZE > + > +/** > + * Various flags supported. > + */ > +/**< Enqueue and reclaim operations are multi-thread safe by default. > + * The call back functions registered to free the resources are > + * assumed to be multi-thread safe. > + * Set this flag is multi-thread safety is not required. > + */ > +#define RTE_RCU_QSBR_DQ_MT_UNSAFE 1 > + > +/** > + * Parameters used when creating the defer queue. > + */ > +struct rte_rcu_qsbr_dq_parameters { > + const char *name; > + /**< Name of the queue. */ > + uint32_t flags; > + /**< Flags to control API behaviors */ > + uint32_t size; > + /**< Number of entries in queue. Typically, this will be > + * the same as the maximum number of entries supported in the > + * lock free data structure. > + * Data structures with unbounded number of entries is not > + * supported currently. > + */ > + uint32_t esize; > + /**< Size (in bytes) of each element in the defer queue. > + * This has to be multiple of 4B. > + */ > + uint32_t trigger_reclaim_limit; > + /**< Trigger automatic reclamation after the defer queue > + * has atleast these many resources waiting. This auto > + * reclamation is triggered in rte_rcu_qsbr_dq_enqueue API > + * call. > + * If this is greater than 'size', auto reclamation is > + * not triggered. > + * If this is set to 0, auto reclamation is triggered > + * in every call to rte_rcu_qsbr_dq_enqueue API. > + */ > + uint32_t max_reclaim_size; > + /**< When automatic reclamation is enabled, reclaim at the max > + * these many resources. This should contain a valid value, if > + * auto reclamation is on. Setting this to 'size' or greater will > + * reclaim all possible resources currently on the defer queue. > + */ > + rte_rcu_qsbr_free_resource_t free_fn; > + /**< Function to call to free the resource. */ > + void *p; > + /**< Pointer passed to the free function. Typically, this is the > + * pointer to the data structure to which the resource to free > + * belongs. This can be NULL. > + */ > + struct rte_rcu_qsbr *v; > + /**< RCU QSBR variable to use for this defer queue */ > +}; > + > +/* RTE defer queue structure. > + * This structure holds the defer queue. The defer queue is used to > + * hold the deleted entries from the data structure that are not > + * yet freed. > + */ > +struct rte_rcu_qsbr_dq; > + > /** > * @warning > * @b EXPERIMENTAL: this API may change without prior notice > @@ -692,6 +772,114 @@ __rte_experimental > int > rte_rcu_qsbr_dump(FILE *f, struct rte_rcu_qsbr *v); >=20 > +/** > + * @warning > + * @b EXPERIMENTAL: this API may change without prior notice > + * > + * Create a queue used to store the data structure elements that can > + * be freed later. This queue is referred to as 'defer queue'. > + * > + * @param params > + * Parameters to create a defer queue. > + * @return > + * On success - Valid pointer to defer queue > + * On error - NULL > + * Possible rte_errno codes are: > + * - EINVAL - NULL parameters are passed > + * - ENOMEM - Not enough memory > + */ > +__rte_experimental > +struct rte_rcu_qsbr_dq * > +rte_rcu_qsbr_dq_create(const struct rte_rcu_qsbr_dq_parameters *params); > + > +/** > + * @warning > + * @b EXPERIMENTAL: this API may change without prior notice > + * > + * Enqueue one resource to the defer queue and start the grace period. > + * The resource will be freed later after at least one grace period > + * is over. > + * > + * If the defer queue is full, it will attempt to reclaim resources. > + * It will also reclaim resources at regular intervals to avoid > + * the defer queue from growing too big. > + * > + * Multi-thread safety is provided as the defer queue configuration. > + * When multi-thread safety is requested, it is possible that the > + * resources are not stored in their order of deletion. This results > + * in resources being held in the defer queue longer than they should. > + * > + * @param dq > + * Defer queue to allocate an entry from. > + * @param e > + * Pointer to resource data to copy to the defer queue. The size of > + * the data to copy is equal to the element size provided when the > + * defer queue was created. > + * @return > + * On success - 0 > + * On error - 1 with rte_errno set to > + * - EINVAL - NULL parameters are passed > + * - ENOSPC - Defer queue is full. This condition can not happen > + * if the defer queue size is equal (or larger) than the > + * number of elements in the data structure. > + */ > +__rte_experimental > +int > +rte_rcu_qsbr_dq_enqueue(struct rte_rcu_qsbr_dq *dq, void *e); > + > +/** > + * @warning > + * @b EXPERIMENTAL: this API may change without prior notice > + * > + * Free quesed resources from the defer queue. > + * > + * This API is multi-thread safe. > + * > + * @param dq > + * Defer queue to free an entry from. > + * @param n > + * Maximum number of resources to free. > + * @param freed > + * Number of resources that were freed. > + * @param pending > + * Number of resources pending on the defer queue. This number might n= ot > + * be acurate if multi-thread safety is configured. > + * @return > + * On successful reclamation of at least 1 resource - 0 > + * On error - 1 with rte_errno set to > + * - EINVAL - NULL parameters are passed > + */ > +__rte_experimental > +int > +rte_rcu_qsbr_dq_reclaim(struct rte_rcu_qsbr_dq *dq, unsigned int n, > + unsigned int *freed, unsigned int *pending); > + > +/** > + * @warning > + * @b EXPERIMENTAL: this API may change without prior notice > + * > + * Delete a defer queue. > + * > + * It tries to reclaim all the resources on the defer queue. > + * If any of the resources have not completed the grace period > + * the reclamation stops and returns immediately. The rest of > + * the resources are not reclaimed and the defer queue is not > + * freed. > + * > + * @param dq > + * Defer queue to delete. > + * @return > + * On success - 0 > + * On error - 1 > + * Possible rte_errno codes are: > + * - EINVAL - NULL parameters are passed > + * - EAGAIN - Some of the resources have not completed at least 1 grac= e > + * period, try again. > + */ > +__rte_experimental > +int > +rte_rcu_qsbr_dq_delete(struct rte_rcu_qsbr_dq *dq); > + > #ifdef __cplusplus > } > #endif > diff --git a/lib/librte_rcu/rte_rcu_version.map b/lib/librte_rcu/rte_rcu_= version.map > index f8b9ef2ab..dfac88a37 100644 > --- a/lib/librte_rcu/rte_rcu_version.map > +++ b/lib/librte_rcu/rte_rcu_version.map > @@ -8,6 +8,10 @@ EXPERIMENTAL { > rte_rcu_qsbr_synchronize; > rte_rcu_qsbr_thread_register; > rte_rcu_qsbr_thread_unregister; > + rte_rcu_qsbr_dq_create; > + rte_rcu_qsbr_dq_enqueue; > + rte_rcu_qsbr_dq_reclaim; > + rte_rcu_qsbr_dq_delete; >=20 > local: *; > }; > diff --git a/lib/meson.build b/lib/meson.build > index 9c3cc55d5..15e91a303 100644 > --- a/lib/meson.build > +++ b/lib/meson.build > @@ -11,7 +11,9 @@ > libraries =3D [ > 'kvargs', # eal depends on kvargs > 'eal', # everything depends on eal > - 'ring', 'mempool', 'mbuf', 'net', 'meter', 'ethdev', 'pci', # core > + 'ring', > + 'rcu', # rcu depends on ring > + 'mempool', 'mbuf', 'net', 'meter', 'ethdev', 'pci', # core > 'cmdline', > 'metrics', # bitrate/latency stats depends on this > 'hash', # efd depends on this > @@ -22,7 +24,7 @@ libraries =3D [ > 'gro', 'gso', 'ip_frag', 'jobstats', > 'kni', 'latencystats', 'lpm', 'member', > 'power', 'pdump', 'rawdev', > - 'rcu', 'rib', 'reorder', 'sched', 'security', 'stack', 'vhost', > + 'rib', 'reorder', 'sched', 'security', 'stack', 'vhost', > # ipsec lib depends on net, crypto and security > 'ipsec', > #fib lib depends on rib > -- > 2.17.1