Re: [PATCH v5 01/10] memarea: introduce memarea library

["Mattias Rönnblom" <hofors@lysator.liu.se>]

On 2022-10-05 06:09, datshan wrote:
> From: Chengwen Feng <fengchengwen@huawei.com>
> 
> The memarea library is an allocator of variable-size object which based
> on a memory region.
> 
> This patch provides create/destroy API.
> 
> Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
> ---
>   MAINTAINERS                            |   5 +
>   doc/api/doxy-api-index.md              |   3 +-
>   doc/api/doxy-api.conf.in               |   1 +
>   doc/guides/prog_guide/index.rst        |   1 +
>   doc/guides/prog_guide/memarea_lib.rst  |  39 ++++++
>   doc/guides/rel_notes/release_22_11.rst |   6 +
>   lib/eal/common/eal_common_log.c        |   1 +
>   lib/eal/include/rte_log.h              |   1 +
>   lib/memarea/memarea_private.h          |  30 +++++
>   lib/memarea/meson.build                |  16 +++
>   lib/memarea/rte_memarea.c              | 157 +++++++++++++++++++++++++
>   lib/memarea/rte_memarea.h              | 145 +++++++++++++++++++++++
>   lib/memarea/version.map                |  12 ++
>   lib/meson.build                        |   1 +
>   14 files changed, 417 insertions(+), 1 deletion(-)
>   create mode 100644 doc/guides/prog_guide/memarea_lib.rst
>   create mode 100644 lib/memarea/memarea_private.h
>   create mode 100644 lib/memarea/meson.build
>   create mode 100644 lib/memarea/rte_memarea.c
>   create mode 100644 lib/memarea/rte_memarea.h
>   create mode 100644 lib/memarea/version.map
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index a55b379d73..b9c638221d 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1550,6 +1550,11 @@ F: app/test/test_lpm*
>   F: app/test/test_func_reentrancy.c
>   F: app/test/test_xmmt_ops.h
>   
> +Memarea - EXPERIMENTAL
> +M: Chengwen Feng <fengchengwen@huawei.com>
> +F: lib/memarea
> +F: doc/guides/prog_guide/memarea_lib.rst
> +
>   Membership - EXPERIMENTAL
>   M: Yipeng Wang <yipeng1.wang@intel.com>
>   M: Sameh Gobriel <sameh.gobriel@intel.com>
> diff --git a/doc/api/doxy-api-index.md b/doc/api/doxy-api-index.md
> index de488c7abf..24456604f8 100644
> --- a/doc/api/doxy-api-index.md
> +++ b/doc/api/doxy-api-index.md
> @@ -62,7 +62,8 @@ The public API headers are grouped by topics:
>     [memzone](@ref rte_memzone.h),
>     [mempool](@ref rte_mempool.h),
>     [malloc](@ref rte_malloc.h),
> -  [memcpy](@ref rte_memcpy.h)
> +  [memcpy](@ref rte_memcpy.h),
> +  [memarea](@ref rte_memarea.h)
>   
>   - **timers**:
>     [cycles](@ref rte_cycles.h),
> diff --git a/doc/api/doxy-api.conf.in b/doc/api/doxy-api.conf.in
> index f0886c3bd1..8334ebcbd6 100644
> --- a/doc/api/doxy-api.conf.in
> +++ b/doc/api/doxy-api.conf.in
> @@ -53,6 +53,7 @@ INPUT                   = @TOPDIR@/doc/api/doxy-api-index.md \
>                             @TOPDIR@/lib/latencystats \
>                             @TOPDIR@/lib/lpm \
>                             @TOPDIR@/lib/mbuf \
> +                          @TOPDIR@/lib/memarea \
>                             @TOPDIR@/lib/member \
>                             @TOPDIR@/lib/mempool \
>                             @TOPDIR@/lib/meter \
> diff --git a/doc/guides/prog_guide/index.rst b/doc/guides/prog_guide/index.rst
> index 8564883018..e9015d65e3 100644
> --- a/doc/guides/prog_guide/index.rst
> +++ b/doc/guides/prog_guide/index.rst
> @@ -37,6 +37,7 @@ Programmer's Guide
>       hash_lib
>       toeplitz_hash_lib
>       efd_lib
> +    memarea_lib
>       member_lib
>       lpm_lib
>       lpm6_lib
> diff --git a/doc/guides/prog_guide/memarea_lib.rst b/doc/guides/prog_guide/memarea_lib.rst
> new file mode 100644
> index 0000000000..b96dad15f6
> --- /dev/null
> +++ b/doc/guides/prog_guide/memarea_lib.rst
> @@ -0,0 +1,39 @@
> +..  SPDX-License-Identifier: BSD-3-Clause
> +    Copyright(c) 2022 HiSilicon Limited
> +
> +Memarea Library
> +===============
> +
> +Introduction
> +------------
> +
> +The memarea library provides an allocator of variable-size objects, it is
> +oriented towards the application layer, which could provides 'region-based
> +memory management' function [1].
> +
> +The main features are as follows:
> +
> +* The default aligement size is ``RTE_CACHE_LINE_SIZE``.
> +
> +* The memory region can be initialized from the following memory sources:
> +  a) RTE memory: e.g. invoke ``rte_malloc_socket`` to obtain. b) System API:
> +  e.g. invoke posix_memalign to obtain. c) User provided address: it can be from
> +  extendedd memory as long as it is available. d) User provided memarea: it can
> +  be from another memarea.
> +
> +* It provides refcnt feature which could be useful in multi-reader scenario.
> +
> +* It supports MT-safe as long as it's specified at creation time.
> +
> +Library API Overview
> +--------------------
> +
> +The ``rte_memarea_create()`` function is used to create a memarea, the function
> +returns the pointer to the created memarea or ``NULL`` if the creation failed.
> +
> +The ``rte_memarea_destroy()`` function is used to destroy a memarea.
> +
> +Reference
> +---------
> +
> +[1] https://en.wikipedia.org/wiki/Region-based_memory_management
> diff --git a/doc/guides/rel_notes/release_22_11.rst b/doc/guides/rel_notes/release_22_11.rst
> index 5d8ef669b8..4c1f760b98 100644
> --- a/doc/guides/rel_notes/release_22_11.rst
> +++ b/doc/guides/rel_notes/release_22_11.rst
> @@ -55,6 +55,12 @@ New Features
>        Also, make sure to start the actual text at the margin.
>        =======================================================
>   
> +* **Added memarea library.**
> +
> +  The memarea library is an allocator of variable-size objects, it is oriented
> +  towards the application layer, which could provides 'region-based memory
> +  management' function.
> +
>   * **Added configuration for asynchronous flow connection tracking.**
>   
>     Added connection tracking action number hint to ``rte_flow_configure``
> diff --git a/lib/eal/common/eal_common_log.c b/lib/eal/common/eal_common_log.c
> index bd7b188ceb..3d62af59c6 100644
> --- a/lib/eal/common/eal_common_log.c
> +++ b/lib/eal/common/eal_common_log.c
> @@ -369,6 +369,7 @@ static const struct logtype logtype_strings[] = {
>   	{RTE_LOGTYPE_EFD,        "lib.efd"},
>   	{RTE_LOGTYPE_EVENTDEV,   "lib.eventdev"},
>   	{RTE_LOGTYPE_GSO,        "lib.gso"},
> +	{RTE_LOGTYPE_MEMAREA,    "lib.memarea"},
>   	{RTE_LOGTYPE_USER1,      "user1"},
>   	{RTE_LOGTYPE_USER2,      "user2"},
>   	{RTE_LOGTYPE_USER3,      "user3"},
> diff --git a/lib/eal/include/rte_log.h b/lib/eal/include/rte_log.h
> index 25ce42cdfc..708f3a39dd 100644
> --- a/lib/eal/include/rte_log.h
> +++ b/lib/eal/include/rte_log.h
> @@ -48,6 +48,7 @@ extern "C" {
>   #define RTE_LOGTYPE_EFD       18 /**< Log related to EFD. */
>   #define RTE_LOGTYPE_EVENTDEV  19 /**< Log related to eventdev. */
>   #define RTE_LOGTYPE_GSO       20 /**< Log related to GSO. */
> +#define RTE_LOGTYPE_MEMAREA   21 /**< Log related to memarea. */
>   
>   /* these log types can be used in an application */
>   #define RTE_LOGTYPE_USER1     24 /**< User-defined log type 1. */
> diff --git a/lib/memarea/memarea_private.h b/lib/memarea/memarea_private.h
> new file mode 100644
> index 0000000000..c76392d3e6
> --- /dev/null
> +++ b/lib/memarea/memarea_private.h
> @@ -0,0 +1,30 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2022 HiSilicon Limited
> + */
> +
> +#ifndef MEMAREA_PRIVATE_H
> +#define MEMAREA_PRIVATE_H
> +
> +#include <rte_memarea.h>
> +
> +#define MEMAREA_FREE_ELEM_COOKIE	0xFFFFFFFF
> +
> +struct memarea_elem {
> +	size_t   size;
> +	uint32_t cookie;
> +	int32_t  refcnt; /* Non-zero indicates that it has been allocated */
> +	TAILQ_ENTRY(memarea_elem) elem_node;
> +	TAILQ_ENTRY(memarea_elem) free_node;
> +} __rte_cache_aligned;
> +

Why is the elem type cache line aligned? Need the elem data start be 
cache line aligned?

> +TAILQ_HEAD(memarea_elem_list, memarea_elem);
> +
> +struct rte_memarea {
> +	struct rte_memarea_param init;
> +	rte_spinlock_t           lock;
> +	void                    *area_addr;
> +	struct memarea_elem_list elem_list;
> +	struct memarea_elem_list free_list;
> +} __rte_cache_aligned;
> +
> +#endif /* MEMAREA_PRIVATE_H */
> diff --git a/lib/memarea/meson.build b/lib/memarea/meson.build
> new file mode 100644
> index 0000000000..0a74fb4cd1
> --- /dev/null
> +++ b/lib/memarea/meson.build
> @@ -0,0 +1,16 @@
> +# SPDX-License-Identifier: BSD-3-Clause
> +# Copyright(c) 2022 HiSilicon Limited
> +
> +if is_windows
> +    build = false
> +    reason = 'not supported on Windows'
> +    subdir_done()
> +endif
> +
> +sources = files(
> +        'rte_memarea.c',
> +)
> +headers = files(
> +        'rte_memarea.h',
> +)
> +deps += []
> diff --git a/lib/memarea/rte_memarea.c b/lib/memarea/rte_memarea.c
> new file mode 100644
> index 0000000000..868da7661d
> --- /dev/null
> +++ b/lib/memarea/rte_memarea.c
> @@ -0,0 +1,157 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2022 HiSilicon Limited
> + */
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +
> +#include <rte_common.h>
> +#include <rte_log.h>
> +#include <rte_malloc.h>
> +#include <rte_spinlock.h>
> +
> +#include "rte_memarea.h"
> +#include "memarea_private.h"
> +
> +static int
> +memarea_check_param(const struct rte_memarea_param *init)
> +{
> +	size_t len;
> +
> +	if (init == NULL) {
> +		RTE_LOG(ERR, MEMAREA, "memarea init param is NULL!\n");
> +		return -EINVAL;
> +	}
> +
> +	len = strnlen(init->name, RTE_MEMAREA_NAMESIZE);
> +	if (len == 0 || len >= RTE_MEMAREA_NAMESIZE) {
> +		RTE_LOG(ERR, MEMAREA, "memarea name size %zu invalid!\n", len);
> +		return -EINVAL;
> +	}
> +
> +	if (init->source != RTE_MEMAREA_SOURCE_RTE_MEMORY &&
> +	    init->source != RTE_MEMAREA_SOURCE_SYSTEM_API &&
> +	    init->source != RTE_MEMAREA_SOURCE_USER_ADDR &&
> +	    init->source != RTE_MEMAREA_SOURCE_USER_MEMAREA) {
> +		RTE_LOG(ERR, MEMAREA, "memarea: %s source: %d not supported!\n",
> +			init->name, init->source);
> +		return -EINVAL;
> +	}
> +
> +	if (init->total_sz <= sizeof(struct memarea_elem)) {
> +		RTE_LOG(ERR, MEMAREA, "memarea: %s total-size: %zu too small!\n",
> +			init->name, init->total_sz);
> +		return -EINVAL;
> +	}
> +
> +	if (init->source == RTE_MEMAREA_SOURCE_USER_ADDR && init->user_addr == NULL) {
> +		RTE_LOG(ERR, MEMAREA, "memarea: %s user provided addr is NULL!\n", init->name);
> +		return -EINVAL;
> +	}
> +
> +	if (init->source == RTE_MEMAREA_SOURCE_USER_ADDR &&
> +	    ((uintptr_t)init->user_addr & (RTE_CACHE_LINE_SIZE - 1))) {
> +		RTE_LOG(ERR, MEMAREA, "memarea: %s user provided addr should align: %d!\n",
> +			init->name, RTE_CACHE_LINE_SIZE);
> +		return -EINVAL;
> +	}
> +
> +	if (init->source == RTE_MEMAREA_SOURCE_USER_MEMAREA && init->user_memarea == NULL) {
> +		RTE_LOG(ERR, MEMAREA, "memarea: %s user provided memarea is NULL!\n", init->name);
> +		return -EINVAL;
> +	}
> +
> +	if (init->alg != RTE_MEMAREA_ALG_DEFAULT) {
> +		RTE_LOG(ERR, MEMAREA, "memarea: %s alg: %d not supported!\n",
> +			init->name, init->alg);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static void *
> +memarea_alloc_from_system_api(size_t size)
> +{
> +	void *ptr = NULL;
> +	int ret;
> +
> +	ret = posix_memalign(&ptr, RTE_CACHE_LINE_SIZE, size);
> +	if (ret)
> +		return NULL;
> +	return ptr;
> +}
> +
> +static void *
> +memarea_alloc_area(const struct rte_memarea_param *init)
> +{
> +	void *ptr = NULL;
> +
> +	if (init->source == RTE_MEMAREA_SOURCE_RTE_MEMORY)

Delete MEMORY. Of course it's memory. What else? If you want to make it 
clear it's from the RTE heap, it should spell out HEAP. Or MALLOC.

> +		ptr = rte_malloc_socket(NULL, init->total_sz, RTE_CACHE_LINE_SIZE,
> +					init->numa_socket);
> +	else if (init->source == RTE_MEMAREA_SOURCE_SYSTEM_API)
> +		ptr = memarea_alloc_from_system_api(init->total_sz);

"SYSTEM_API" doesn't strike me as a good name.

RTE_MEMAREA_SOURCE_LIBC
RTE_MEMAREA_SOURCE_STD_HEAP
or at least remove API so it'll be
RTE_MEMAREA_SOURCE_SYSTEM

> +	else if (init->source == RTE_MEMAREA_SOURCE_USER_ADDR)

I would delete "ADDR".

> +		ptr = init->user_addr;
> +
> +	if (ptr == NULL)
> +		RTE_LOG(ERR, MEMAREA, "memarea: %s alloc memory area fail!\n", init->name);
> +
> +	return ptr;
> +}
> +
> +struct rte_memarea *
> +rte_memarea_create(const struct rte_memarea_param *init)
> +{
> +	struct memarea_elem *elem;
> +	struct rte_memarea *ma;
> +	void *addr;
> +	int ret;
> +
> +	ret = memarea_check_param(init);
> +	if (ret)
> +		return NULL;
> +
> +	addr = memarea_alloc_area(init);
> +	if (addr == NULL)
> +		return NULL;
> +
> +	ma = rte_zmalloc(NULL, sizeof(struct rte_memarea), RTE_CACHE_LINE_SIZE);
> +	if (ma == NULL) {
> +		RTE_LOG(ERR, MEMAREA, "malloc memarea: %s management obj fail!\n", init->name);
> +		return NULL;
> +	}
> +
> +	ma->init = *init;
> +	rte_spinlock_init(&ma->lock);
> +	TAILQ_INIT(&ma->elem_list);
> +	TAILQ_INIT(&ma->free_list);
> +	ma->area_addr = addr;
> +	elem = addr;
> +	elem->size = init->total_sz - sizeof(struct memarea_elem);
> +	elem->cookie = MEMAREA_FREE_ELEM_COOKIE;
> +	elem->refcnt = 0;
> +	TAILQ_INSERT_TAIL(&ma->elem_list, elem, elem_node);
> +	TAILQ_INSERT_TAIL(&ma->free_list, elem, free_node);
> +
> +	return ma;
> +}
> +
> +static void
> +memarea_free_area(struct rte_memarea *ma)
> +{
> +	if (ma->init.source == RTE_MEMAREA_SOURCE_RTE_MEMORY)
> +		rte_free(ma->area_addr);
> +	else if (ma->init.source == RTE_MEMAREA_SOURCE_SYSTEM_API)
> +		free(ma->area_addr);
> +}
> +
> +void
> +rte_memarea_destroy(struct rte_memarea *ma)
> +{
> +	if (ma == NULL)
> +		return;
> +	memarea_free_area(ma);
> +	rte_free(ma);
> +}
> diff --git a/lib/memarea/rte_memarea.h b/lib/memarea/rte_memarea.h
> new file mode 100644
> index 0000000000..543cda4cac
> --- /dev/null
> +++ b/lib/memarea/rte_memarea.h
> @@ -0,0 +1,145 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2022 HiSilicon Limited
> + */
> +
> +#ifndef RTE_MEMAREA_H
> +#define RTE_MEMAREA_H
> +
> +/**
> + * @file
> + * RTE Memarea.
> + *
> + * The memarea is an allocator of variable-size object which based on a memory
> + * region. It has the following features:
> + *
> + * - The default alignment size is RTE_CACHE_LINE_SIZE.

This can be read as two things: the object size is aligned, or the start 
address is aligned.

> + * - The memory region can be initialized from the following memory sources:
> + *   1. RTE memory: e.g. invoke rte_malloc_socket to obtain.

Remove "to obtain", or add "memory" after "obtain". Do you really mean 
"e.g.", and not "i.e."?

> + *   2. System API: e.g. invoke posix_memalign to obtain.
> + *   3. User provided address: it can be from extended memory as long as it is
> + *      available. The address must be aligned to RTE_CACHE_LINE_SIZE.

What is extended memory?

> + *   4) User provided memarea: it can be from another memarea. So we can build
> + *      the following memory management structure:
> + *         \code{.unparsed}
> + *                           -------------
> + *                           | memarea-1 |
> + *                           -------------
> + *                                 |
> + *                                 v
> + *                  -------------------------------
> + *                  |               |             |
> + *                  v               v             v
> + *            -------------   -------------   ----------
> + *            | memarea-2 |   | memarea-3 |   | object |
> + *            -------------   -------------   ----------
> + *         \endcode
> + *      As shown above, the memarea-2/3 both create from memarea-1's memory.
> + * - It provides refcnt feature which could be useful in multi-reader scenario.
> + * - It supports MT-safe as long as it's specified at creation time. If not
> + *   specified, all the functions of the memarea API are lock-free, and assume
> + *   to not be invoked in parallel on different logical cores to work on the
> + *   same memarea.
> + */
> +
> +#include <stdbool.h>
> +#include <stdint.h>
> +#include <stdio.h>
> +
> +#include <rte_compat.h>
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +#define RTE_MEMAREA_NAMESIZE	64
> +
> +/**
> + * Memarea memory source.
> + */
> +enum rte_memarea_source {
> +	/** Memory source comes from rte memory. */
> +	RTE_MEMAREA_SOURCE_RTE_MEMORY,
> +	/** Memory source comes from system API. */
> +	RTE_MEMAREA_SOURCE_SYSTEM_API,
> +	/** Memory source comes from user-provided address. */
> +	RTE_MEMAREA_SOURCE_USER_ADDR,
> +	/** Memory source comes from user-provided memarea. */
> +	RTE_MEMAREA_SOURCE_USER_MEMAREA,
> +};
> +
> +/**
> + * Memarea memory management algorithm.
> + */
> +enum rte_memarea_alg {
> +	/* The default management algorithm is a variant of the next fit
> +	 * algorithm. It uses a free-list to apply for memory and uses an
> +	 * element-list in ascending order of address to support merging
> +	 * upon free.
> +	 */
> +	RTE_MEMAREA_ALG_DEFAULT,
> +};
> +
> +struct rte_memarea;
> +
> +struct rte_memarea_param {

Does this struct need to be public?

> +	char name[RTE_MEMAREA_NAMESIZE]; /**< Name of memarea. */
> +	enum rte_memarea_source source;  /**< Memory source of memarea. */
> +	enum rte_memarea_alg alg;        /**< Memory management algorithm. */
> +	size_t total_sz;                 /**< total size (bytes) of memarea. */
> +	/** Indicates whether the memarea API should be MT-safe. */
> +	uint32_t mt_safe : 1;

Why not bool?

> +	union {
> +		/** Numa socket from which to apply for memarea's memory, this
> +		 * field is valid only when the source is set to be
> +		 * RTE_MEMAREA_SOURCE_RTE_MEMORY.
> +		 */
> +		int numa_socket;
> +		/** User provided address, this field is valid only when the
> +		 * source is set to be RTE_MEMAREA_SOURCE_USER_ADDR.
> +		 * Note: the provided address must align at least
> +		 * RTE_CACHE_LINE_SIZE.
> +		 */
> +		void *user_addr;
> +		/** User provided memarea, this field is valid only when the
> +		 * source is set to be RTE_MEMAREA_SOURCE_USER_MEMAREA.
> +		 */
> +		struct rte_memarea *user_memarea;
> +	};
> +};
> +
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice.
> + *
> + * Create memarea.
> + *
> + * Create one new memarea.
> + *
> + * @param init
> + *   The init parameter of memarea.
> + *
> + * @return
> + *   Non-NULL on success. Otherwise NULL is returned.
> + */
> +__rte_experimental
> +struct rte_memarea *rte_memarea_create(const struct rte_memarea_param *init);
> +
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice.
> + *
> + * Destroy memarea.
> + *
> + * Destroy the memarea.
> + *
> + * @param ma
> + *   The pointer of memarea.
> + */
> +__rte_experimental
> +void rte_memarea_destroy(struct rte_memarea *ma);
> +
> +#ifdef __cplusplus
> +}
> +#endif
> +
> +#endif /* RTE_MEMAREA_H */
> diff --git a/lib/memarea/version.map b/lib/memarea/version.map
> new file mode 100644
> index 0000000000..f36a04d7cf
> --- /dev/null
> +++ b/lib/memarea/version.map
> @@ -0,0 +1,12 @@
> +EXPERIMENTAL {
> +	global:
> +
> +	rte_memarea_create;
> +	rte_memarea_destroy;
> +
> +	local: *;
> +};
> +
> +INTERNAL {
> +	local: *;
> +};
> diff --git a/lib/meson.build b/lib/meson.build
> index c648f7d800..521a25d6c0 100644
> --- a/lib/meson.build
> +++ b/lib/meson.build
> @@ -42,6 +42,7 @@ libraries = [
>           'kni',
>           'latencystats',
>           'lpm',
> +        'memarea',
>           'member',
>           'pcapng',
>           'power',