diff mbox series

[v6,3/5] mbuf: create packet pool with external memory buffers

Message ID 1579547786-7650-4-git-send-email-viacheslavo@mellanox.com (mailing list archive)
State Accepted, archived
Delegated to: Thomas Monjalon
Headers show
Series mbuf: detach mbuf with pinned external buffer | expand

Checks

Context Check Description
ci/Intel-compilation success Compilation OK
ci/checkpatch success coding style OK

Commit Message

Slava Ovsiienko Jan. 20, 2020, 7:16 p.m. UTC
The dedicated routine rte_pktmbuf_pool_create_extbuf() is
provided to create mbuf pool with data buffers located in
the pinned external memory. The application provides the
external memory description and routine initializes each
mbuf with appropriate virtual and physical buffer address.
It is entirely application responsibility to register
external memory with rte_extmem_register() API, map this
memory, etc.

The new introduced flag RTE_PKTMBUF_POOL_F_PINNED_EXT_BUF
is set in private pool structure, specifying the new special
pool type. The allocated mbufs from pool of this kind will
have the EXT_ATTACHED_MBUF flag set and initialiazed shared
info structure, allowing cloning with regular mbufs (without
attached external buffers of any kind).

Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
---
 lib/librte_mbuf/rte_mbuf.c           | 204 ++++++++++++++++++++++++++++++++++-
 lib/librte_mbuf/rte_mbuf.h           |  58 +++++++++-
 lib/librte_mbuf/rte_mbuf_version.map |   1 +
 3 files changed, 260 insertions(+), 3 deletions(-)

Comments

Stephen Hemminger Jan. 20, 2020, 8:48 p.m. UTC | #1
On Mon, 20 Jan 2020 19:16:24 +0000
Viacheslav Ovsiienko <viacheslavo@mellanox.com> wrote:

> +		((user_mbp_priv->flags & RTE_PKTMBUF_POOL_F_PINNED_EXT_BUF) ?
> +			sizeof(struct rte_mbuf_ext_shared_info) :
> +			user_mbp_priv->mbuf_data_room_size

Should rte_pktmbuf_data_room_size() be used, and have it return the
right value for external mbuf?
Slava Ovsiienko Jan. 21, 2020, 7:04 a.m. UTC | #2
> -----Original Message-----
> From: Stephen Hemminger <stephen@networkplumber.org>
> Sent: Monday, January 20, 2020 22:48
> To: Slava Ovsiienko <viacheslavo@mellanox.com>
> Cc: dev@dpdk.org; Matan Azrad <matan@mellanox.com>; Raslan Darawsheh
> <rasland@mellanox.com>; Ori Kam <orika@mellanox.com>; Shahaf Shuler
> <shahafs@mellanox.com>; olivier.matz@6wind.com; thomas@mellanox.net
> Subject: Re: [PATCH v6 3/5] mbuf: create packet pool with external memory
> buffers
> 
> On Mon, 20 Jan 2020 19:16:24 +0000
> Viacheslav Ovsiienko <viacheslavo@mellanox.com> wrote:
> 
> > +		((user_mbp_priv->flags &
> RTE_PKTMBUF_POOL_F_PINNED_EXT_BUF) ?
> > +			sizeof(struct rte_mbuf_ext_shared_info) :
> > +			user_mbp_priv->mbuf_data_room_size
> 
> Should rte_pktmbuf_data_room_size() be used, and have it return the right
> value for external mbuf?

The pool initialization is not completed yet (private structure of mbuf pool is
not copied yet, so in this point  rte_pktmbuf_data_room_size() is unable to fetch
the valid data room size. Beside this,  rte_pktmbuf_data_room_size() returns the
valid value for the mbuf with pinned external buffers after pool initialization is done.

With best regards, Slava
diff mbox series

Patch

diff --git a/lib/librte_mbuf/rte_mbuf.c b/lib/librte_mbuf/rte_mbuf.c
index 8fa7f49..25eea1d 100644
--- a/lib/librte_mbuf/rte_mbuf.c
+++ b/lib/librte_mbuf/rte_mbuf.c
@@ -59,9 +59,12 @@ 
 	}
 
 	RTE_ASSERT(mp->elt_size >= sizeof(struct rte_mbuf) +
-		user_mbp_priv->mbuf_data_room_size +
+		((user_mbp_priv->flags & RTE_PKTMBUF_POOL_F_PINNED_EXT_BUF) ?
+			sizeof(struct rte_mbuf_ext_shared_info) :
+			user_mbp_priv->mbuf_data_room_size) +
 		user_mbp_priv->mbuf_priv_size);
-	RTE_ASSERT(user_mbp_priv->flags == 0);
+	RTE_ASSERT((user_mbp_priv->flags &
+		    ~RTE_PKTMBUF_POOL_F_PINNED_EXT_BUF) == 0);
 
 	mbp_priv = rte_mempool_get_priv(mp);
 	memcpy(mbp_priv, user_mbp_priv, sizeof(*mbp_priv));
@@ -107,6 +110,116 @@ 
 	m->next = NULL;
 }
 
+/*
+ * @internal The callback routine called when reference counter in shinfo
+ * for mbufs with pinned external buffer reaches zero. It means there is
+ * no more reference to buffer backing mbuf and this one should be freed.
+ * This routine is called for the regular (not with pinned external or
+ * indirect buffer) mbufs on detaching from the mbuf with pinned external
+ * buffer.
+ */
+static void rte_pktmbuf_free_pinned_extmem(void *addr, void *opaque)
+{
+	struct rte_mbuf *m = opaque;
+
+	RTE_SET_USED(addr);
+	RTE_ASSERT(RTE_MBUF_HAS_EXTBUF(m));
+	RTE_ASSERT(RTE_MBUF_HAS_PINNED_EXTBUF(m));
+	RTE_ASSERT(m->shinfo->fcb_opaque == m);
+
+	rte_mbuf_ext_refcnt_set(m->shinfo, 1);
+	m->ol_flags = EXT_ATTACHED_MBUF;
+	if (m->next != NULL) {
+		m->next = NULL;
+		m->nb_segs = 1;
+	}
+	rte_mbuf_raw_free(m);
+}
+
+/** The context to initialize the mbufs with pinned external buffers. */
+struct rte_pktmbuf_extmem_init_ctx {
+	const struct rte_pktmbuf_extmem *ext_mem; /* descriptor array. */
+	unsigned int ext_num; /* number of descriptors in array. */
+	unsigned int ext; /* loop descriptor index. */
+	size_t off; /* loop buffer offset. */
+};
+
+/**
+ * @internal Packet mbuf constructor for pools with pinned external memory.
+ *
+ * This function initializes some fields in the mbuf structure that are
+ * not modified by the user once created (origin pool, buffer start
+ * address, and so on). This function is given as a callback function to
+ * rte_mempool_obj_iter() called from rte_mempool_create_extmem().
+ *
+ * @param mp
+ *   The mempool from which mbufs originate.
+ * @param opaque_arg
+ *   A pointer to the rte_pktmbuf_extmem_init_ctx - initialization
+ *   context structure
+ * @param m
+ *   The mbuf to initialize.
+ * @param i
+ *   The index of the mbuf in the pool table.
+ */
+static void
+__rte_pktmbuf_init_extmem(struct rte_mempool *mp,
+			  void *opaque_arg,
+			  void *_m,
+			  __attribute__((unused)) unsigned int i)
+{
+	struct rte_mbuf *m = _m;
+	struct rte_pktmbuf_extmem_init_ctx *ctx = opaque_arg;
+	const struct rte_pktmbuf_extmem *ext_mem;
+	uint32_t mbuf_size, buf_len, priv_size;
+	struct rte_mbuf_ext_shared_info *shinfo;
+
+	priv_size = rte_pktmbuf_priv_size(mp);
+	mbuf_size = sizeof(struct rte_mbuf) + priv_size;
+	buf_len = rte_pktmbuf_data_room_size(mp);
+
+	RTE_ASSERT(RTE_ALIGN(priv_size, RTE_MBUF_PRIV_ALIGN) == priv_size);
+	RTE_ASSERT(mp->elt_size >= mbuf_size);
+	RTE_ASSERT(buf_len <= UINT16_MAX);
+
+	memset(m, 0, mbuf_size);
+	m->priv_size = priv_size;
+	m->buf_len = (uint16_t)buf_len;
+
+	/* set the data buffer pointers to external memory */
+	ext_mem = ctx->ext_mem + ctx->ext;
+
+	RTE_ASSERT(ctx->ext < ctx->ext_num);
+	RTE_ASSERT(ctx->off < ext_mem->buf_len);
+
+	m->buf_addr = RTE_PTR_ADD(ext_mem->buf_ptr, ctx->off);
+	m->buf_iova = ext_mem->buf_iova == RTE_BAD_IOVA ?
+		      RTE_BAD_IOVA : (ext_mem->buf_iova + ctx->off);
+
+	ctx->off += ext_mem->elt_size;
+	if (ctx->off >= ext_mem->buf_len) {
+		ctx->off = 0;
+		++ctx->ext;
+	}
+	/* keep some headroom between start of buffer and data */
+	m->data_off = RTE_MIN(RTE_PKTMBUF_HEADROOM, (uint16_t)m->buf_len);
+
+	/* init some constant fields */
+	m->pool = mp;
+	m->nb_segs = 1;
+	m->port = MBUF_INVALID_PORT;
+	m->ol_flags = EXT_ATTACHED_MBUF;
+	rte_mbuf_refcnt_set(m, 1);
+	m->next = NULL;
+
+	/* init external buffer shared info items */
+	shinfo = RTE_PTR_ADD(m, mbuf_size);
+	m->shinfo = shinfo;
+	shinfo->free_cb = rte_pktmbuf_free_pinned_extmem;
+	shinfo->fcb_opaque = m;
+	rte_mbuf_ext_refcnt_set(shinfo, 1);
+}
+
 /* Helper to create a mbuf pool with given mempool ops name*/
 struct rte_mempool *
 rte_pktmbuf_pool_create_by_ops(const char *name, unsigned int n,
@@ -169,6 +282,93 @@  struct rte_mempool *
 			data_room_size, socket_id, NULL);
 }
 
+/* Helper to create a mbuf pool with pinned external data buffers. */
+struct rte_mempool *
+rte_pktmbuf_pool_create_extbuf(const char *name, unsigned int n,
+	unsigned int cache_size, uint16_t priv_size,
+	uint16_t data_room_size, int socket_id,
+	const struct rte_pktmbuf_extmem *ext_mem,
+	unsigned int ext_num)
+{
+	struct rte_mempool *mp;
+	struct rte_pktmbuf_pool_private mbp_priv;
+	struct rte_pktmbuf_extmem_init_ctx init_ctx;
+	const char *mp_ops_name;
+	unsigned int elt_size;
+	unsigned int i, n_elts = 0;
+	int ret;
+
+	if (RTE_ALIGN(priv_size, RTE_MBUF_PRIV_ALIGN) != priv_size) {
+		RTE_LOG(ERR, MBUF, "mbuf priv_size=%u is not aligned\n",
+			priv_size);
+		rte_errno = EINVAL;
+		return NULL;
+	}
+	/* Check the external memory descriptors. */
+	for (i = 0; i < ext_num; i++) {
+		const struct rte_pktmbuf_extmem *extm = ext_mem + i;
+
+		if (!extm->elt_size || !extm->buf_len || !extm->buf_ptr) {
+			RTE_LOG(ERR, MBUF, "invalid extmem descriptor\n");
+			rte_errno = EINVAL;
+			return NULL;
+		}
+		if (data_room_size > extm->elt_size) {
+			RTE_LOG(ERR, MBUF, "ext elt_size=%u is too small\n",
+				priv_size);
+			rte_errno = EINVAL;
+			return NULL;
+		}
+		n_elts += extm->buf_len / extm->elt_size;
+	}
+	/* Check whether enough external memory provided. */
+	if (n_elts < n) {
+		RTE_LOG(ERR, MBUF, "not enough extmem\n");
+		rte_errno = ENOMEM;
+		return NULL;
+	}
+	elt_size = sizeof(struct rte_mbuf) +
+		   (unsigned int)priv_size +
+		   sizeof(struct rte_mbuf_ext_shared_info);
+
+	memset(&mbp_priv, 0, sizeof(mbp_priv));
+	mbp_priv.mbuf_data_room_size = data_room_size;
+	mbp_priv.mbuf_priv_size = priv_size;
+	mbp_priv.flags = RTE_PKTMBUF_POOL_F_PINNED_EXT_BUF;
+
+	mp = rte_mempool_create_empty(name, n, elt_size, cache_size,
+		 sizeof(struct rte_pktmbuf_pool_private), socket_id, 0);
+	if (mp == NULL)
+		return NULL;
+
+	mp_ops_name = rte_mbuf_best_mempool_ops();
+	ret = rte_mempool_set_ops_byname(mp, mp_ops_name, NULL);
+	if (ret != 0) {
+		RTE_LOG(ERR, MBUF, "error setting mempool handler\n");
+		rte_mempool_free(mp);
+		rte_errno = -ret;
+		return NULL;
+	}
+	rte_pktmbuf_pool_init(mp, &mbp_priv);
+
+	ret = rte_mempool_populate_default(mp);
+	if (ret < 0) {
+		rte_mempool_free(mp);
+		rte_errno = -ret;
+		return NULL;
+	}
+
+	init_ctx = (struct rte_pktmbuf_extmem_init_ctx){
+		.ext_mem = ext_mem,
+		.ext_num = ext_num,
+		.ext = 0,
+		.off = 0,
+	};
+	rte_mempool_obj_iter(mp, __rte_pktmbuf_init_extmem, &init_ctx);
+
+	return mp;
+}
+
 /* do some sanity checks on a mbuf: panic if it fails */
 void
 rte_mbuf_sanity_check(const struct rte_mbuf *m, int is_header)
diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index c4f5085..5902389 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -637,7 +637,6 @@  static inline struct rte_mbuf *rte_mbuf_raw_alloc(struct rte_mempool *mp)
 void rte_pktmbuf_init(struct rte_mempool *mp, void *opaque_arg,
 		      void *m, unsigned i);
 
-
 /**
  * A  packet mbuf pool constructor.
  *
@@ -738,6 +737,63 @@  struct rte_mempool *
 	unsigned int cache_size, uint16_t priv_size, uint16_t data_room_size,
 	int socket_id, const char *ops_name);
 
+/** A structure that describes the pinned external buffer segment. */
+struct rte_pktmbuf_extmem {
+	void *buf_ptr;		/**< The virtual address of data buffer. */
+	rte_iova_t buf_iova;	/**< The IO address of the data buffer. */
+	size_t buf_len;		/**< External buffer length in bytes. */
+	uint16_t elt_size;	/**< mbuf element size in bytes. */
+};
+
+/**
+ * Create a mbuf pool with external pinned data buffers.
+ *
+ * This function creates and initializes a packet mbuf pool that contains
+ * only mbufs with external buffer. It is a wrapper to rte_mempool functions.
+ *
+ * @param name
+ *   The name of the mbuf pool.
+ * @param n
+ *   The number of elements in the mbuf pool. The optimum size (in terms
+ *   of memory usage) for a mempool is when n is a power of two minus one:
+ *   n = (2^q - 1).
+ * @param cache_size
+ *   Size of the per-core object cache. See rte_mempool_create() for
+ *   details.
+ * @param priv_size
+ *   Size of application private are between the rte_mbuf structure
+ *   and the data buffer. This value must be aligned to RTE_MBUF_PRIV_ALIGN.
+ * @param data_room_size
+ *   Size of data buffer in each mbuf, including RTE_PKTMBUF_HEADROOM.
+ * @param socket_id
+ *   The socket identifier where the memory should be allocated. The
+ *   value can be *SOCKET_ID_ANY* if there is no NUMA constraint for the
+ *   reserved zone.
+ * @param ext_mem
+ *   Pointer to the array of structures describing the external memory
+ *   for data buffers. It is caller responsibility to register this memory
+ *   with rte_extmem_register() (if needed), map this memory to appropriate
+ *   physical device, etc.
+ * @param ext_num
+ *   Number of elements in the ext_mem array.
+ * @return
+ *   The pointer to the new allocated mempool, on success. NULL on error
+ *   with rte_errno set appropriately. Possible rte_errno values include:
+ *    - E_RTE_NO_CONFIG - function could not get pointer to rte_config structure
+ *    - E_RTE_SECONDARY - function was called from a secondary process instance
+ *    - EINVAL - cache size provided is too large, or priv_size is not aligned.
+ *    - ENOSPC - the maximum number of memzones has already been allocated
+ *    - EEXIST - a memzone with the same name already exists
+ *    - ENOMEM - no appropriate memory area found in which to create memzone
+ */
+__rte_experimental
+struct rte_mempool *
+rte_pktmbuf_pool_create_extbuf(const char *name, unsigned int n,
+	unsigned int cache_size, uint16_t priv_size,
+	uint16_t data_room_size, int socket_id,
+	const struct rte_pktmbuf_extmem *ext_mem,
+	unsigned int ext_num);
+
 /**
  * Get the data room size of mbufs stored in a pktmbuf_pool
  *
diff --git a/lib/librte_mbuf/rte_mbuf_version.map b/lib/librte_mbuf/rte_mbuf_version.map
index 3bbb476..ab161bc 100644
--- a/lib/librte_mbuf/rte_mbuf_version.map
+++ b/lib/librte_mbuf/rte_mbuf_version.map
@@ -44,5 +44,6 @@  EXPERIMENTAL {
 	rte_mbuf_dyn_dump;
 	rte_pktmbuf_copy;
 	rte_pktmbuf_free_bulk;
+	rte_pktmbuf_pool_create_extbuf;
 
 };