[v5,1/4] lib/rcu: add resource reclamation APIs
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Commit Message
Add resource reclamation APIs to make it simple for applications
and libraries to integrate rte_rcu library.
Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Ola Liljedhal <ola.liljedhal@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
---
lib/librte_rcu/Makefile | 2 +-
lib/librte_rcu/meson.build | 7 +
lib/librte_rcu/rcu_qsbr_pvt.h | 66 +++++++++
lib/librte_rcu/rte_rcu_qsbr.c | 227 ++++++++++++++++++++++++++++-
lib/librte_rcu/rte_rcu_qsbr.h | 194 +++++++++++++++++++++++-
lib/librte_rcu/rte_rcu_version.map | 4 +
lib/meson.build | 6 +-
7 files changed, 501 insertions(+), 5 deletions(-)
create mode 100644 lib/librte_rcu/rcu_qsbr_pvt.h
Comments
> Add resource reclamation APIs to make it simple for applications
> and libraries to integrate rte_rcu library.
>
> Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> Reviewed-by: Ola Liljedhal <ola.liljedhal@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> ---
> lib/librte_rcu/Makefile | 2 +-
> lib/librte_rcu/meson.build | 7 +
> lib/librte_rcu/rcu_qsbr_pvt.h | 66 +++++++++
> lib/librte_rcu/rte_rcu_qsbr.c | 227 ++++++++++++++++++++++++++++-
> lib/librte_rcu/rte_rcu_qsbr.h | 194 +++++++++++++++++++++++-
> lib/librte_rcu/rte_rcu_version.map | 4 +
> lib/meson.build | 6 +-
> 7 files changed, 501 insertions(+), 5 deletions(-)
> create mode 100644 lib/librte_rcu/rcu_qsbr_pvt.h
>
> diff --git a/lib/librte_rcu/Makefile b/lib/librte_rcu/Makefile
> index 728669975..553bca2ef 100644
> --- a/lib/librte_rcu/Makefile
> +++ b/lib/librte_rcu/Makefile
> @@ -7,7 +7,7 @@ include $(RTE_SDK)/mk/rte.vars.mk
> LIB = librte_rcu.a
>
> CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
> -LDLIBS += -lrte_eal
> +LDLIBS += -lrte_eal -lrte_ring
>
> EXPORT_MAP := rte_rcu_version.map
>
> diff --git a/lib/librte_rcu/meson.build b/lib/librte_rcu/meson.build
> index c009ae4b7..3eb2ace17 100644
> --- a/lib/librte_rcu/meson.build
> +++ b/lib/librte_rcu/meson.build
> @@ -3,3 +3,10 @@
>
> sources = files('rte_rcu_qsbr.c')
> headers = files('rte_rcu_qsbr.h')
> +
> +# for clang 32-bit compiles we need libatomic for 64-bit atomic ops
> +if cc.get_id() == 'clang' and dpdk_conf.get('RTE_ARCH_64') == false
> + ext_deps += cc.find_library('atomic')
> +endif
> +
As a nit - as Pavan patch is already integrated into mainline,
this is not necessary any more, I think.
Also noticed that most of make builds failed due to dependency problem:
http://mails.dpdk.org/archives/test-report/2020-April/127765.html
I can't reproduce it locally, but my guess that we need to move rcu above
ring in this mk file: mk/rte.app.mk
Probably something like that:
diff --git a/mk/rte.app.mk b/mk/rte.app.mk
index da12b9eec..8e5d023de 100644
--- a/mk/rte.app.mk
+++ b/mk/rte.app.mk
@@ -91,13 +91,13 @@ _LDLIBS-$(CONFIG_RTE_LIBRTE_MEMPOOL) += -lrte_mempool
_LDLIBS-$(CONFIG_RTE_LIBRTE_STACK) += -lrte_stack
_LDLIBS-$(CONFIG_RTE_DRIVER_MEMPOOL_RING) += -lrte_mempool_ring
_LDLIBS-$(CONFIG_RTE_LIBRTE_OCTEONTX2_MEMPOOL) += -lrte_mempool_octeontx2
+_LDLIBS-$(CONFIG_RTE_LIBRTE_RCU) += -lrte_rcu
_LDLIBS-$(CONFIG_RTE_LIBRTE_RING) += -lrte_ring
_LDLIBS-$(CONFIG_RTE_LIBRTE_PCI) += -lrte_pci
_LDLIBS-$(CONFIG_RTE_LIBRTE_EAL) += -lrte_eal
_LDLIBS-$(CONFIG_RTE_LIBRTE_CMDLINE) += -lrte_cmdline
_LDLIBS-$(CONFIG_RTE_LIBRTE_REORDER) += -lrte_reorder
_LDLIBS-$(CONFIG_RTE_LIBRTE_SCHED) += -lrte_sched
-_LDLIBS-$(CONFIG_RTE_LIBRTE_RCU) += -lrte_rcu
Apart from that - LGTM
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> +deps += ['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..63f7a5fff
> --- /dev/null
> +++ b/lib/librte_rcu/rcu_qsbr_pvt.h
> @@ -0,0 +1,66 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright (c) 2020 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 <rte_ring.h>
> +#include <rte_ring_elem.h>
> +
> +#include "rte_rcu_qsbr.h"
> +
> +/* 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.
> + */
> +};
> +
> +/* Internal structure to represent the element on the defer queue.
> + * Use alias as a character array is type casted to a variable
> + * of this structure type.
> + */
> +typedef struct {
> + uint64_t token; /**< Token */
> + uint8_t elem[0]; /**< Pointer to user element */
> +} __attribute__((__may_alias__)) __rte_rcu_qsbr_dq_elem_t;
> +
> +#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..6a429d8b3 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) 2018-2020 Arm Limited
> */
>
> #include <stdio.h>
> @@ -18,8 +18,10 @@
> #include <rte_per_lcore.h>
> #include <rte_lcore.h>
> #include <rte_errno.h>
> +#include <rte_ring_elem.h>
>
> #include "rte_rcu_qsbr.h"
> +#include "rcu_qsbr_pvt.h"
>
> /* Get the memory size of QSBR variable */
> size_t
> @@ -270,6 +272,229 @@ rte_rcu_qsbr_dump(FILE *f, struct rte_rcu_qsbr *v)
> return 0;
> }
>
> +/* 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 == NULL || params->free_fn == NULL ||
> + params->v == NULL || params->name == NULL ||
> + params->size == 0 || params->esize == 0 ||
> + (params->esize % 4 != 0)) {
> + rte_log(RTE_LOG_ERR, rte_rcu_log_type,
> + "%s(): Invalid input parameter\n", __func__);
> + rte_errno = EINVAL;
> +
> + return NULL;
> + }
> + /* If auto reclamation is configured, reclaim limit
> + * should be a valid value.
> + */
> + if ((params->trigger_reclaim_limit <= params->size) &&
> + (params->max_reclaim_size == 0)) {
> + rte_log(RTE_LOG_ERR, rte_rcu_log_type,
> + "%s(): Invalid input parameter, size = %u, trigger_reclaim_limit = %u, max_reclaim_size = %u\n",
> + __func__, params->size, params->trigger_reclaim_limit,
> + params->max_reclaim_size);
> + rte_errno = EINVAL;
> +
> + return NULL;
> + }
> +
> + dq = rte_zmalloc(NULL, sizeof(struct rte_rcu_qsbr_dq),
> + RTE_CACHE_LINE_SIZE);
> + if (dq == NULL) {
> + rte_errno = 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 = RING_F_MP_RTS_ENQ;
> + if (params->flags & RTE_RCU_QSBR_DQ_MT_UNSAFE)
> + flags = RING_F_SP_ENQ;
> + flags |= 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 = rte_align32pow2(params->size + 1);
> + /* Add token size to ring element size */
> + dq->r = rte_ring_create_elem(params->name,
> + __RTE_QSBR_TOKEN_SIZE + params->esize,
> + qs_fifo_size, SOCKET_ID_ANY, flags);
> + if (dq->r == NULL) {
> + rte_log(RTE_LOG_ERR, rte_rcu_log_type,
> + "%s(): defer queue create failed\n", __func__);
> + rte_free(dq);
> + return NULL;
> + }
> +
> + dq->v = params->v;
> + dq->size = params->size;
> + dq->esize = __RTE_QSBR_TOKEN_SIZE + params->esize;
> + dq->trigger_reclaim_limit = params->trigger_reclaim_limit;
> + dq->max_reclaim_size = params->max_reclaim_size;
> + dq->free_fn = params->free_fn;
> + dq->p = 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)
> +{
> + __rte_rcu_qsbr_dq_elem_t *dq_elem;
> + uint32_t cur_size;
> +
> + if (dq == NULL || e == NULL) {
> + rte_log(RTE_LOG_ERR, rte_rcu_log_type,
> + "%s(): Invalid input parameter\n", __func__);
> + rte_errno = EINVAL;
> +
> + return 1;
> + }
> +
> + char data[dq->esize];
> + dq_elem = (__rte_rcu_qsbr_dq_elem_t *)data;
> + /* Start the grace period */
> + dq_elem->token = rte_rcu_qsbr_start(dq->v);
> +
> + /* Reclaim resources if the queue size has hit the reclaim
> + * limit. This helps the queue from growing too large and
> + * allows time for reader threads to report their quiescent state.
> + */
> + cur_size = 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, NULL);
> + }
> +
> + /* Enqueue the token and resource. Generating the token and
> + * enqueuing (token + resource) on the queue is not an
> + * atomic operation. When the defer queue is shared by multiple
> + * writers, 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.
> + */
> + memcpy(dq_elem->elem, e, dq->esize - __RTE_QSBR_TOKEN_SIZE);
> + /* Check the status as enqueue might fail since the other threads
> + * 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) != 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 = %"PRIu64"\n",
> + __func__, dq_elem->token);
> +
> + rte_errno = ENOSPC;
> + return 1;
> + }
> +
> + rte_log(RTE_LOG_INFO, rte_rcu_log_type,
> + "%s(): Enqueued token = %"PRIu64"\n", __func__, dq_elem->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,
> + unsigned int *available)
> +{
> + uint32_t cnt;
> + __rte_rcu_qsbr_dq_elem_t *dq_elem;
> +
> + if (dq == NULL || n == 0) {
> + rte_log(RTE_LOG_ERR, rte_rcu_log_type,
> + "%s(): Invalid input parameter\n", __func__);
> + rte_errno = EINVAL;
> +
> + return 1;
> + }
> +
> + cnt = 0;
> +
> + char data[dq->esize];
> + /* Check reader threads quiescent state and reclaim resources */
> + while (cnt < n &&
> + rte_ring_dequeue_bulk_elem_start(dq->r, &data,
> + dq->esize, 1, available) != 0) {
> + dq_elem = (__rte_rcu_qsbr_dq_elem_t *)data;
> +
> + /* Reclaim the resource */
> + if (rte_rcu_qsbr_check(dq->v, dq_elem->token, false) != 1) {
> + rte_ring_dequeue_elem_finish(dq->r, 0);
> + break;
> + }
> + rte_ring_dequeue_elem_finish(dq->r, 1);
> +
> + rte_log(RTE_LOG_INFO, rte_rcu_log_type,
> + "%s(): Reclaimed token = %"PRIu64"\n",
> + __func__, dq_elem->token);
> +
> + dq->free_fn(dq->p, dq_elem->elem, 1);
> +
> + cnt++;
> + }
> +
> + rte_log(RTE_LOG_INFO, rte_rcu_log_type,
> + "%s(): Reclaimed %u resources\n", __func__, cnt);
> +
> + if (freed != NULL)
> + *freed = cnt;
> + if (pending != NULL)
> + *pending = 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 == NULL) {
> + rte_log(RTE_LOG_DEBUG, rte_rcu_log_type,
> + "%s(): Invalid input parameter\n", __func__);
> +
> + return 0;
> + }
> +
> + /* Reclaim all the resources */
> + rte_rcu_qsbr_dq_reclaim(dq, ~0, NULL, &pending, NULL);
> + if (pending != 0) {
> + rte_errno = EAGAIN;
> +
> + return 1;
> + }
> +
> + rte_ring_free(dq->r);
> + rte_free(dq);
> +
> + return 0;
> +}
> +
> int rte_rcu_log_type;
>
> 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..e2fc7f83e 100644
> --- a/lib/librte_rcu/rte_rcu_qsbr.h
> +++ b/lib/librte_rcu/rte_rcu_qsbr.h
> @@ -1,5 +1,5 @@
> /* SPDX-License-Identifier: BSD-3-Clause
> - * Copyright (c) 2018 Arm Limited
> + * Copyright (c) 2018-2020 Arm Limited
> */
>
> #ifndef _RTE_RCU_QSBR_H_
> @@ -34,6 +34,7 @@ extern "C" {
> #include <rte_lcore.h>
> #include <rte_debug.h>
> #include <rte_atomic.h>
> +#include <rte_ring.h>
>
> extern int rte_rcu_log_type;
>
> @@ -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)
>
> /* RTE Quiescent State variable structure.
> * This structure has two elements that vary in size based on the
> @@ -114,6 +116,86 @@ struct rte_rcu_qsbr {
> */
> } __rte_cache_aligned;
>
> +/**
> + * 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
> + * @param n
> + * Number of resources to free. Currently, this is set to 1.
> + *
> + * @return
> + * None
> + */
> +typedef void (*rte_rcu_qsbr_free_resource_t)(void *p, void *e, unsigned int n);
> +
> +#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 +774,116 @@ __rte_experimental
> int
> rte_rcu_qsbr_dump(FILE *f, struct rte_rcu_qsbr *v);
>
> +/**
> + * @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 not
> + * be acurate if multi-thread safety is configured.
> + * @param available
> + * Number of resources that can be added to the defer queue.
> + * This number might not 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, unsigned int *available);
> +
> +/**
> + * @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:
> + * - EAGAIN - Some of the resources have not completed at least 1 grace
> + * 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;
>
> local: *;
> };
> diff --git a/lib/meson.build b/lib/meson.build
> index 63c17ee75..c28b8df83 100644
> --- a/lib/meson.build
> +++ b/lib/meson.build
> @@ -11,7 +11,9 @@
> libraries = [
> '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 = [
> '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
On Wed, Apr 22, 2020 at 10:37 AM Ananyev, Konstantin
<konstantin.ananyev@intel.com> wrote:
>
> > Add resource reclamation APIs to make it simple for applications
> > and libraries to integrate rte_rcu library.
> >
> > Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> > Reviewed-by: Ola Liljedhal <ola.liljedhal@arm.com>
> > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> > Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> > ---
> > lib/librte_rcu/Makefile | 2 +-
> > lib/librte_rcu/meson.build | 7 +
> > lib/librte_rcu/rcu_qsbr_pvt.h | 66 +++++++++
> > lib/librte_rcu/rte_rcu_qsbr.c | 227 ++++++++++++++++++++++++++++-
> > lib/librte_rcu/rte_rcu_qsbr.h | 194 +++++++++++++++++++++++-
> > lib/librte_rcu/rte_rcu_version.map | 4 +
> > lib/meson.build | 6 +-
> > 7 files changed, 501 insertions(+), 5 deletions(-)
> > create mode 100644 lib/librte_rcu/rcu_qsbr_pvt.h
> >
> > diff --git a/lib/librte_rcu/Makefile b/lib/librte_rcu/Makefile
> > index 728669975..553bca2ef 100644
> > --- a/lib/librte_rcu/Makefile
> > +++ b/lib/librte_rcu/Makefile
> > @@ -7,7 +7,7 @@ include $(RTE_SDK)/mk/rte.vars.mk
> > LIB = librte_rcu.a
> >
> > CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
> > -LDLIBS += -lrte_eal
> > +LDLIBS += -lrte_eal -lrte_ring
> >
> > EXPORT_MAP := rte_rcu_version.map
> >
> > diff --git a/lib/librte_rcu/meson.build b/lib/librte_rcu/meson.build
> > index c009ae4b7..3eb2ace17 100644
> > --- a/lib/librte_rcu/meson.build
> > +++ b/lib/librte_rcu/meson.build
> > @@ -3,3 +3,10 @@
> >
> > sources = files('rte_rcu_qsbr.c')
> > headers = files('rte_rcu_qsbr.h')
> > +
> > +# for clang 32-bit compiles we need libatomic for 64-bit atomic ops
> > +if cc.get_id() == 'clang' and dpdk_conf.get('RTE_ARCH_64') == false
> > + ext_deps += cc.find_library('atomic')
> > +endif
> > +
>
> As a nit - as Pavan patch is already integrated into mainline,
> this is not necessary any more, I think.
I can handle this.
> Also noticed that most of make builds failed due to dependency problem:
> http://mails.dpdk.org/archives/test-report/2020-April/127765.html
> I can't reproduce it locally, but my guess that we need to move rcu above
> ring in this mk file: mk/rte.app.mk
> Probably something like that:
> diff --git a/mk/rte.app.mk b/mk/rte.app.mk
> index da12b9eec..8e5d023de 100644
> --- a/mk/rte.app.mk
> +++ b/mk/rte.app.mk
> @@ -91,13 +91,13 @@ _LDLIBS-$(CONFIG_RTE_LIBRTE_MEMPOOL) += -lrte_mempool
> _LDLIBS-$(CONFIG_RTE_LIBRTE_STACK) += -lrte_stack
> _LDLIBS-$(CONFIG_RTE_DRIVER_MEMPOOL_RING) += -lrte_mempool_ring
> _LDLIBS-$(CONFIG_RTE_LIBRTE_OCTEONTX2_MEMPOOL) += -lrte_mempool_octeontx2
> +_LDLIBS-$(CONFIG_RTE_LIBRTE_RCU) += -lrte_rcu
> _LDLIBS-$(CONFIG_RTE_LIBRTE_RING) += -lrte_ring
> _LDLIBS-$(CONFIG_RTE_LIBRTE_PCI) += -lrte_pci
> _LDLIBS-$(CONFIG_RTE_LIBRTE_EAL) += -lrte_eal
> _LDLIBS-$(CONFIG_RTE_LIBRTE_CMDLINE) += -lrte_cmdline
> _LDLIBS-$(CONFIG_RTE_LIBRTE_REORDER) += -lrte_reorder
> _LDLIBS-$(CONFIG_RTE_LIBRTE_SCHED) += -lrte_sched
> -_LDLIBS-$(CONFIG_RTE_LIBRTE_RCU) += -lrte_rcu
No, just moving will not express a dependency.
On Wed, Apr 22, 2020 at 10:42 AM David Marchand
<david.marchand@redhat.com> wrote:
>
> On Wed, Apr 22, 2020 at 10:37 AM Ananyev, Konstantin
> <konstantin.ananyev@intel.com> wrote:
> >
> > > Add resource reclamation APIs to make it simple for applications
> > > and libraries to integrate rte_rcu library.
> > >
> > > Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> > > Reviewed-by: Ola Liljedhal <ola.liljedhal@arm.com>
> > > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> > > Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> > > ---
> > > lib/librte_rcu/Makefile | 2 +-
> > > lib/librte_rcu/meson.build | 7 +
> > > lib/librte_rcu/rcu_qsbr_pvt.h | 66 +++++++++
> > > lib/librte_rcu/rte_rcu_qsbr.c | 227 ++++++++++++++++++++++++++++-
> > > lib/librte_rcu/rte_rcu_qsbr.h | 194 +++++++++++++++++++++++-
> > > lib/librte_rcu/rte_rcu_version.map | 4 +
> > > lib/meson.build | 6 +-
> > > 7 files changed, 501 insertions(+), 5 deletions(-)
> > > create mode 100644 lib/librte_rcu/rcu_qsbr_pvt.h
> > >
> > > diff --git a/lib/librte_rcu/Makefile b/lib/librte_rcu/Makefile
> > > index 728669975..553bca2ef 100644
> > > --- a/lib/librte_rcu/Makefile
> > > +++ b/lib/librte_rcu/Makefile
> > > @@ -7,7 +7,7 @@ include $(RTE_SDK)/mk/rte.vars.mk
> > > LIB = librte_rcu.a
> > >
> > > CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
> > > -LDLIBS += -lrte_eal
> > > +LDLIBS += -lrte_eal -lrte_ring
> > >
> > > EXPORT_MAP := rte_rcu_version.map
> > >
> > > diff --git a/lib/librte_rcu/meson.build b/lib/librte_rcu/meson.build
> > > index c009ae4b7..3eb2ace17 100644
> > > --- a/lib/librte_rcu/meson.build
> > > +++ b/lib/librte_rcu/meson.build
> > > @@ -3,3 +3,10 @@
> > >
> > > sources = files('rte_rcu_qsbr.c')
> > > headers = files('rte_rcu_qsbr.h')
> > > +
> > > +# for clang 32-bit compiles we need libatomic for 64-bit atomic ops
> > > +if cc.get_id() == 'clang' and dpdk_conf.get('RTE_ARCH_64') == false
> > > + ext_deps += cc.find_library('atomic')
> > > +endif
> > > +
> >
> > As a nit - as Pavan patch is already integrated into mainline,
> > this is not necessary any more, I think.
>
> I can handle this.
>
>
> > Also noticed that most of make builds failed due to dependency problem:
> > http://mails.dpdk.org/archives/test-report/2020-April/127765.html
> > I can't reproduce it locally, but my guess that we need to move rcu above
> > ring in this mk file: mk/rte.app.mk
> > Probably something like that:
> > diff --git a/mk/rte.app.mk b/mk/rte.app.mk
> > index da12b9eec..8e5d023de 100644
> > --- a/mk/rte.app.mk
> > +++ b/mk/rte.app.mk
> > @@ -91,13 +91,13 @@ _LDLIBS-$(CONFIG_RTE_LIBRTE_MEMPOOL) += -lrte_mempool
> > _LDLIBS-$(CONFIG_RTE_LIBRTE_STACK) += -lrte_stack
> > _LDLIBS-$(CONFIG_RTE_DRIVER_MEMPOOL_RING) += -lrte_mempool_ring
> > _LDLIBS-$(CONFIG_RTE_LIBRTE_OCTEONTX2_MEMPOOL) += -lrte_mempool_octeontx2
> > +_LDLIBS-$(CONFIG_RTE_LIBRTE_RCU) += -lrte_rcu
> > _LDLIBS-$(CONFIG_RTE_LIBRTE_RING) += -lrte_ring
> > _LDLIBS-$(CONFIG_RTE_LIBRTE_PCI) += -lrte_pci
> > _LDLIBS-$(CONFIG_RTE_LIBRTE_EAL) += -lrte_eal
> > _LDLIBS-$(CONFIG_RTE_LIBRTE_CMDLINE) += -lrte_cmdline
> > _LDLIBS-$(CONFIG_RTE_LIBRTE_REORDER) += -lrte_reorder
> > _LDLIBS-$(CONFIG_RTE_LIBRTE_SCHED) += -lrte_sched
> > -_LDLIBS-$(CONFIG_RTE_LIBRTE_RCU) += -lrte_rcu
>
> No, just moving will not express a dependency.
Fixed with:
diff --git a/lib/Makefile b/lib/Makefile
index 2cbb096f1..8bc0c2e4a 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -118,6 +118,7 @@ DIRS-$(CONFIG_RTE_LIBRTE_TELEMETRY) += librte_telemetry
DEPDIRS-librte_telemetry := librte_eal librte_metrics librte_ethdev
DIRS-$(CONFIG_RTE_LIBRTE_RCU) += librte_rcu
-DEPDIRS-librte_rcu := librte_eal
+DEPDIRS-librte_rcu := librte_eal librte_ring
ifeq ($(CONFIG_RTE_EXEC_ENV_LINUX),y)
DIRS-$(CONFIG_RTE_LIBRTE_KNI) += librte_kni
diff --git a/lib/librte_rcu/meson.build b/lib/librte_rcu/meson.build
index 3eb2ace17..09abc5204 100644
--- a/lib/librte_rcu/meson.build
+++ b/lib/librte_rcu/meson.build
@@ -4,9 +4,4 @@
sources = files('rte_rcu_qsbr.c')
headers = files('rte_rcu_qsbr.h')
-# for clang 32-bit compiles we need libatomic for 64-bit atomic ops
-if cc.get_id() == 'clang' and dpdk_conf.get('RTE_ARCH_64') == false
- ext_deps += cc.find_library('atomic')
-endif
-
deps += ['ring']
>
> On Wed, Apr 22, 2020 at 10:42 AM David Marchand
> <david.marchand@redhat.com> wrote:
> >
> > On Wed, Apr 22, 2020 at 10:37 AM Ananyev, Konstantin
> > <konstantin.ananyev@intel.com> wrote:
> > >
> > > > Add resource reclamation APIs to make it simple for applications
> > > > and libraries to integrate rte_rcu library.
> > > >
> > > > Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> > > > Reviewed-by: Ola Liljedhal <ola.liljedhal@arm.com>
> > > > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> > > > Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> > > > ---
> > > > lib/librte_rcu/Makefile | 2 +-
> > > > lib/librte_rcu/meson.build | 7 +
> > > > lib/librte_rcu/rcu_qsbr_pvt.h | 66 +++++++++
> > > > lib/librte_rcu/rte_rcu_qsbr.c | 227 ++++++++++++++++++++++++++++-
> > > > lib/librte_rcu/rte_rcu_qsbr.h | 194 +++++++++++++++++++++++-
> > > > lib/librte_rcu/rte_rcu_version.map | 4 +
> > > > lib/meson.build | 6 +-
> > > > 7 files changed, 501 insertions(+), 5 deletions(-)
> > > > create mode 100644 lib/librte_rcu/rcu_qsbr_pvt.h
> > > >
> > > > diff --git a/lib/librte_rcu/Makefile b/lib/librte_rcu/Makefile
> > > > index 728669975..553bca2ef 100644
> > > > --- a/lib/librte_rcu/Makefile
> > > > +++ b/lib/librte_rcu/Makefile
> > > > @@ -7,7 +7,7 @@ include $(RTE_SDK)/mk/rte.vars.mk
> > > > LIB = librte_rcu.a
> > > >
> > > > CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
> > > > -LDLIBS += -lrte_eal
> > > > +LDLIBS += -lrte_eal -lrte_ring
> > > >
> > > > EXPORT_MAP := rte_rcu_version.map
> > > >
> > > > diff --git a/lib/librte_rcu/meson.build b/lib/librte_rcu/meson.build
> > > > index c009ae4b7..3eb2ace17 100644
> > > > --- a/lib/librte_rcu/meson.build
> > > > +++ b/lib/librte_rcu/meson.build
> > > > @@ -3,3 +3,10 @@
> > > >
> > > > sources = files('rte_rcu_qsbr.c')
> > > > headers = files('rte_rcu_qsbr.h')
> > > > +
> > > > +# for clang 32-bit compiles we need libatomic for 64-bit atomic ops
> > > > +if cc.get_id() == 'clang' and dpdk_conf.get('RTE_ARCH_64') == false
> > > > + ext_deps += cc.find_library('atomic')
> > > > +endif
> > > > +
> > >
> > > As a nit - as Pavan patch is already integrated into mainline,
> > > this is not necessary any more, I think.
> >
> > I can handle this.
> >
> >
> > > Also noticed that most of make builds failed due to dependency problem:
> > > http://mails.dpdk.org/archives/test-report/2020-April/127765.html
> > > I can't reproduce it locally, but my guess that we need to move rcu above
> > > ring in this mk file: mk/rte.app.mk
> > > Probably something like that:
> > > diff --git a/mk/rte.app.mk b/mk/rte.app.mk
> > > index da12b9eec..8e5d023de 100644
> > > --- a/mk/rte.app.mk
> > > +++ b/mk/rte.app.mk
> > > @@ -91,13 +91,13 @@ _LDLIBS-$(CONFIG_RTE_LIBRTE_MEMPOOL) += -lrte_mempool
> > > _LDLIBS-$(CONFIG_RTE_LIBRTE_STACK) += -lrte_stack
> > > _LDLIBS-$(CONFIG_RTE_DRIVER_MEMPOOL_RING) += -lrte_mempool_ring
> > > _LDLIBS-$(CONFIG_RTE_LIBRTE_OCTEONTX2_MEMPOOL) += -lrte_mempool_octeontx2
> > > +_LDLIBS-$(CONFIG_RTE_LIBRTE_RCU) += -lrte_rcu
> > > _LDLIBS-$(CONFIG_RTE_LIBRTE_RING) += -lrte_ring
> > > _LDLIBS-$(CONFIG_RTE_LIBRTE_PCI) += -lrte_pci
> > > _LDLIBS-$(CONFIG_RTE_LIBRTE_EAL) += -lrte_eal
> > > _LDLIBS-$(CONFIG_RTE_LIBRTE_CMDLINE) += -lrte_cmdline
> > > _LDLIBS-$(CONFIG_RTE_LIBRTE_REORDER) += -lrte_reorder
> > > _LDLIBS-$(CONFIG_RTE_LIBRTE_SCHED) += -lrte_sched
> > > -_LDLIBS-$(CONFIG_RTE_LIBRTE_RCU) += -lrte_rcu
> >
> > No, just moving will not express a dependency.
>
> Fixed with:
>
> diff --git a/lib/Makefile b/lib/Makefile
> index 2cbb096f1..8bc0c2e4a 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -118,6 +118,7 @@ DIRS-$(CONFIG_RTE_LIBRTE_TELEMETRY) += librte_telemetry
> DEPDIRS-librte_telemetry := librte_eal librte_metrics librte_ethdev
> DIRS-$(CONFIG_RTE_LIBRTE_RCU) += librte_rcu
> -DEPDIRS-librte_rcu := librte_eal
> +DEPDIRS-librte_rcu := librte_eal librte_ring
Right, totally forgot about that part.
>
> ifeq ($(CONFIG_RTE_EXEC_ENV_LINUX),y)
> DIRS-$(CONFIG_RTE_LIBRTE_KNI) += librte_kni
> diff --git a/lib/librte_rcu/meson.build b/lib/librte_rcu/meson.build
> index 3eb2ace17..09abc5204 100644
> --- a/lib/librte_rcu/meson.build
> +++ b/lib/librte_rcu/meson.build
> @@ -4,9 +4,4 @@
> sources = files('rte_rcu_qsbr.c')
> headers = files('rte_rcu_qsbr.h')
>
> -# for clang 32-bit compiles we need libatomic for 64-bit atomic ops
> -if cc.get_id() == 'clang' and dpdk_conf.get('RTE_ARCH_64') == false
> - ext_deps += cc.find_library('atomic')
> -endif
> -
> deps += ['ring']
>
>
> --
> David Marchand
@@ -7,7 +7,7 @@ include $(RTE_SDK)/mk/rte.vars.mk
LIB = librte_rcu.a
CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3
-LDLIBS += -lrte_eal
+LDLIBS += -lrte_eal -lrte_ring
EXPORT_MAP := rte_rcu_version.map
@@ -3,3 +3,10 @@
sources = files('rte_rcu_qsbr.c')
headers = files('rte_rcu_qsbr.h')
+
+# for clang 32-bit compiles we need libatomic for 64-bit atomic ops
+if cc.get_id() == 'clang' and dpdk_conf.get('RTE_ARCH_64') == false
+ ext_deps += cc.find_library('atomic')
+endif
+
+deps += ['ring']
new file mode 100644
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright (c) 2020 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 <rte_ring.h>
+#include <rte_ring_elem.h>
+
+#include "rte_rcu_qsbr.h"
+
+/* 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.
+ */
+};
+
+/* Internal structure to represent the element on the defer queue.
+ * Use alias as a character array is type casted to a variable
+ * of this structure type.
+ */
+typedef struct {
+ uint64_t token; /**< Token */
+ uint8_t elem[0]; /**< Pointer to user element */
+} __attribute__((__may_alias__)) __rte_rcu_qsbr_dq_elem_t;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTE_RCU_QSBR_PVT_H_ */
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: BSD-3-Clause
*
- * Copyright (c) 2018 Arm Limited
+ * Copyright (c) 2018-2020 Arm Limited
*/
#include <stdio.h>
@@ -18,8 +18,10 @@
#include <rte_per_lcore.h>
#include <rte_lcore.h>
#include <rte_errno.h>
+#include <rte_ring_elem.h>
#include "rte_rcu_qsbr.h"
+#include "rcu_qsbr_pvt.h"
/* Get the memory size of QSBR variable */
size_t
@@ -270,6 +272,229 @@ rte_rcu_qsbr_dump(FILE *f, struct rte_rcu_qsbr *v)
return 0;
}
+/* 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 == NULL || params->free_fn == NULL ||
+ params->v == NULL || params->name == NULL ||
+ params->size == 0 || params->esize == 0 ||
+ (params->esize % 4 != 0)) {
+ rte_log(RTE_LOG_ERR, rte_rcu_log_type,
+ "%s(): Invalid input parameter\n", __func__);
+ rte_errno = EINVAL;
+
+ return NULL;
+ }
+ /* If auto reclamation is configured, reclaim limit
+ * should be a valid value.
+ */
+ if ((params->trigger_reclaim_limit <= params->size) &&
+ (params->max_reclaim_size == 0)) {
+ rte_log(RTE_LOG_ERR, rte_rcu_log_type,
+ "%s(): Invalid input parameter, size = %u, trigger_reclaim_limit = %u, max_reclaim_size = %u\n",
+ __func__, params->size, params->trigger_reclaim_limit,
+ params->max_reclaim_size);
+ rte_errno = EINVAL;
+
+ return NULL;
+ }
+
+ dq = rte_zmalloc(NULL, sizeof(struct rte_rcu_qsbr_dq),
+ RTE_CACHE_LINE_SIZE);
+ if (dq == NULL) {
+ rte_errno = 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 = RING_F_MP_RTS_ENQ;
+ if (params->flags & RTE_RCU_QSBR_DQ_MT_UNSAFE)
+ flags = RING_F_SP_ENQ;
+ flags |= 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 = rte_align32pow2(params->size + 1);
+ /* Add token size to ring element size */
+ dq->r = rte_ring_create_elem(params->name,
+ __RTE_QSBR_TOKEN_SIZE + params->esize,
+ qs_fifo_size, SOCKET_ID_ANY, flags);
+ if (dq->r == NULL) {
+ rte_log(RTE_LOG_ERR, rte_rcu_log_type,
+ "%s(): defer queue create failed\n", __func__);
+ rte_free(dq);
+ return NULL;
+ }
+
+ dq->v = params->v;
+ dq->size = params->size;
+ dq->esize = __RTE_QSBR_TOKEN_SIZE + params->esize;
+ dq->trigger_reclaim_limit = params->trigger_reclaim_limit;
+ dq->max_reclaim_size = params->max_reclaim_size;
+ dq->free_fn = params->free_fn;
+ dq->p = 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)
+{
+ __rte_rcu_qsbr_dq_elem_t *dq_elem;
+ uint32_t cur_size;
+
+ if (dq == NULL || e == NULL) {
+ rte_log(RTE_LOG_ERR, rte_rcu_log_type,
+ "%s(): Invalid input parameter\n", __func__);
+ rte_errno = EINVAL;
+
+ return 1;
+ }
+
+ char data[dq->esize];
+ dq_elem = (__rte_rcu_qsbr_dq_elem_t *)data;
+ /* Start the grace period */
+ dq_elem->token = rte_rcu_qsbr_start(dq->v);
+
+ /* Reclaim resources if the queue size has hit the reclaim
+ * limit. This helps the queue from growing too large and
+ * allows time for reader threads to report their quiescent state.
+ */
+ cur_size = 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, NULL);
+ }
+
+ /* Enqueue the token and resource. Generating the token and
+ * enqueuing (token + resource) on the queue is not an
+ * atomic operation. When the defer queue is shared by multiple
+ * writers, 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.
+ */
+ memcpy(dq_elem->elem, e, dq->esize - __RTE_QSBR_TOKEN_SIZE);
+ /* Check the status as enqueue might fail since the other threads
+ * 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) != 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 = %"PRIu64"\n",
+ __func__, dq_elem->token);
+
+ rte_errno = ENOSPC;
+ return 1;
+ }
+
+ rte_log(RTE_LOG_INFO, rte_rcu_log_type,
+ "%s(): Enqueued token = %"PRIu64"\n", __func__, dq_elem->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,
+ unsigned int *available)
+{
+ uint32_t cnt;
+ __rte_rcu_qsbr_dq_elem_t *dq_elem;
+
+ if (dq == NULL || n == 0) {
+ rte_log(RTE_LOG_ERR, rte_rcu_log_type,
+ "%s(): Invalid input parameter\n", __func__);
+ rte_errno = EINVAL;
+
+ return 1;
+ }
+
+ cnt = 0;
+
+ char data[dq->esize];
+ /* Check reader threads quiescent state and reclaim resources */
+ while (cnt < n &&
+ rte_ring_dequeue_bulk_elem_start(dq->r, &data,
+ dq->esize, 1, available) != 0) {
+ dq_elem = (__rte_rcu_qsbr_dq_elem_t *)data;
+
+ /* Reclaim the resource */
+ if (rte_rcu_qsbr_check(dq->v, dq_elem->token, false) != 1) {
+ rte_ring_dequeue_elem_finish(dq->r, 0);
+ break;
+ }
+ rte_ring_dequeue_elem_finish(dq->r, 1);
+
+ rte_log(RTE_LOG_INFO, rte_rcu_log_type,
+ "%s(): Reclaimed token = %"PRIu64"\n",
+ __func__, dq_elem->token);
+
+ dq->free_fn(dq->p, dq_elem->elem, 1);
+
+ cnt++;
+ }
+
+ rte_log(RTE_LOG_INFO, rte_rcu_log_type,
+ "%s(): Reclaimed %u resources\n", __func__, cnt);
+
+ if (freed != NULL)
+ *freed = cnt;
+ if (pending != NULL)
+ *pending = 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 == NULL) {
+ rte_log(RTE_LOG_DEBUG, rte_rcu_log_type,
+ "%s(): Invalid input parameter\n", __func__);
+
+ return 0;
+ }
+
+ /* Reclaim all the resources */
+ rte_rcu_qsbr_dq_reclaim(dq, ~0, NULL, &pending, NULL);
+ if (pending != 0) {
+ rte_errno = EAGAIN;
+
+ return 1;
+ }
+
+ rte_ring_free(dq->r);
+ rte_free(dq);
+
+ return 0;
+}
+
int rte_rcu_log_type;
RTE_INIT(rte_rcu_register)
@@ -1,5 +1,5 @@
/* SPDX-License-Identifier: BSD-3-Clause
- * Copyright (c) 2018 Arm Limited
+ * Copyright (c) 2018-2020 Arm Limited
*/
#ifndef _RTE_RCU_QSBR_H_
@@ -34,6 +34,7 @@ extern "C" {
#include <rte_lcore.h>
#include <rte_debug.h>
#include <rte_atomic.h>
+#include <rte_ring.h>
extern int rte_rcu_log_type;
@@ -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)
/* RTE Quiescent State variable structure.
* This structure has two elements that vary in size based on the
@@ -114,6 +116,86 @@ struct rte_rcu_qsbr {
*/
} __rte_cache_aligned;
+/**
+ * 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
+ * @param n
+ * Number of resources to free. Currently, this is set to 1.
+ *
+ * @return
+ * None
+ */
+typedef void (*rte_rcu_qsbr_free_resource_t)(void *p, void *e, unsigned int n);
+
+#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 +774,116 @@ __rte_experimental
int
rte_rcu_qsbr_dump(FILE *f, struct rte_rcu_qsbr *v);
+/**
+ * @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 not
+ * be acurate if multi-thread safety is configured.
+ * @param available
+ * Number of resources that can be added to the defer queue.
+ * This number might not 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, unsigned int *available);
+
+/**
+ * @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:
+ * - EAGAIN - Some of the resources have not completed at least 1 grace
+ * period, try again.
+ */
+__rte_experimental
+int
+rte_rcu_qsbr_dq_delete(struct rte_rcu_qsbr_dq *dq);
+
#ifdef __cplusplus
}
#endif
@@ -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;
local: *;
};
@@ -11,7 +11,9 @@
libraries = [
'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 = [
'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