[dpdk-dev] [PATCH v9 0/2] mbuf: add bulk free function

[dpdk-dev] [PATCH v9 0/2] mbuf: add bulk free function

[Morten Brørup]

Add function for freeing a bulk of mbufs.

Add unit test for functions for allocating and freeing a bulk of mbufs.

Signed-off-by: Morten Brørup <mb@smartsharesystems.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Olivier Matz <olivier.matz@6wind.com>

---

v9:
* Fix a typo in a description.
* In the unit test, make chain length a #define and add a few
  RTE_BUILD_BUG_ON().
* The unit test prints when allocating the mbuf pools for the bulk tests.
  Also print when freeing them.
v8:
* Add unit test, covering both bulk alloc and bulk free.
v7:
* Squash multiple modifications into one.
v6:
* Remove __rte_always_inline from static function.
  The compiler will inline anyway.
v5:
* Rename variables from "free" to "pending" for improved readability.
* Add prefix __ to rte_pktmbuf_free_seg_via_array().
* Add array size parameter to __rte_pktmbuf_free_seg_via_array().
  The compiler will optimize the parameter away anyway.
* Add description to __rte_pktmbuf_free_seg_via_array().
* Minor description updates.
v4:
* Mark as experimental by adding __rte_experimental.
* Add function to experimental section of map file.
* Fix source code formatting regarding pointer to pointer.
* Squash multiple modifications into one.
v3:
* Bugfix: Handle pakets with multiple segments.
* Add inline helper function, mainly for readability.
* Fix source code formatting regarding indentation.
v2:
* Function is not inline.
* Optimize to free multible mbufs belonging to the same mempool in
  bulk. Inspired by ixgbe_tx_free_bufs(), but allowing NULL pointers
  in the array, just like rte_pktmbuf_free() can take a NULL pointer.
* Use unsigned int instead of unsigned. Passes checkpatch, but
  mismatches the original coding style of the modified files.
* Fix a typo in the description headline: mempools is plural.


Morten Brørup (2):
  mbuf: add bulk free function
  mbuf: add unit test for bulk alloc/free functions

 app/test/test_mbuf.c                 | 179 +++++++++++++++++++++++++++
 lib/librte_mbuf/rte_mbuf.c           |  66 ++++++++++
 lib/librte_mbuf/rte_mbuf.h           |  15 +++
 lib/librte_mbuf/rte_mbuf_version.map |   1 +
 4 files changed, 261 insertions(+)

-- 
2.17.1

[dpdk-dev] [PATCH v9 1/2] mbuf: add bulk free function

[Morten Brørup]

Add function for freeing a bulk of mbufs.

Signed-off-by: Morten Brørup <mb@smartsharesystems.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Olivier Matz <olivier.matz@6wind.com>

---

v9:
* Fix a typo in a description.
* In the unit test, make chain length a #define and add a few
  RTE_BUILD_BUG_ON().
* The unit test prints when allocating the mbuf pools for the bulk tests.
  Also print when freeing them.
v8:
* Add unit test, covering both bulk alloc and bulk free.
v7:
* Squash multiple modifications into one.
v6:
* Remove __rte_always_inline from static function.
  The compiler will inline anyway.
v5:
* Rename variables from "free" to "pending" for improved readability.
* Add prefix __ to rte_pktmbuf_free_seg_via_array().
* Add array size parameter to __rte_pktmbuf_free_seg_via_array().
  The compiler will optimize the parameter away anyway.
* Add description to __rte_pktmbuf_free_seg_via_array().
* Minor description updates.
v4:
* Mark as experimental by adding __rte_experimental.
* Add function to experimental section of map file.
* Fix source code formatting regarding pointer to pointer.
* Squash multiple modifications into one.
v3:
* Bugfix: Handle pakets with multiple segments.
* Add inline helper function, mainly for readability.
* Fix source code formatting regarding indentation.
v2:
* Function is not inline.
* Optimize to free multible mbufs belonging to the same mempool in
  bulk. Inspired by ixgbe_tx_free_bufs(), but allowing NULL pointers
  in the array, just like rte_pktmbuf_free() can take a NULL pointer.
* Use unsigned int instead of unsigned. Passes checkpatch, but
  mismatches the original coding style of the modified files.
* Fix a typo in the description headline: mempools is plural.
---
 lib/librte_mbuf/rte_mbuf.c           | 66 ++++++++++++++++++++++++++++
 lib/librte_mbuf/rte_mbuf.h           | 15 +++++++
 lib/librte_mbuf/rte_mbuf_version.map |  1 +
 3 files changed, 82 insertions(+)

diff --git a/lib/librte_mbuf/rte_mbuf.c b/lib/librte_mbuf/rte_mbuf.c
index 0236fba76..b0d292c6e 100644
--- a/lib/librte_mbuf/rte_mbuf.c
+++ b/lib/librte_mbuf/rte_mbuf.c
@@ -245,6 +245,72 @@ int rte_mbuf_check(const struct rte_mbuf *m, int is_header,
 	return 0;
 }
 
+/**
+ * @internal helper function for freeing a bulk of packet mbuf segments
+ * via an array holding the packet mbuf segments from the same mempool
+ * pending to be freed.
+ *
+ * @param m
+ *  The packet mbuf segment to be freed.
+ * @param pending
+ *  Pointer to the array of packet mbuf segments pending to be freed.
+ * @param nb_pending
+ *  Pointer to the number of elements held in the array.
+ * @param pending_sz
+ *  Number of elements the array can hold.
+ *  Note: The compiler should optimize this parameter away when using a
+ *  constant value, such as RTE_PKTMBUF_FREE_PENDING_SZ.
+ */
+static void
+__rte_pktmbuf_free_seg_via_array(struct rte_mbuf *m,
+	struct rte_mbuf ** const pending, unsigned int * const nb_pending,
+	const unsigned int pending_sz)
+{
+	m = rte_pktmbuf_prefree_seg(m);
+	if (likely(m != NULL)) {
+		if (*nb_pending == pending_sz ||
+		    (*nb_pending > 0 && m->pool != pending[0]->pool)) {
+			rte_mempool_put_bulk(pending[0]->pool,
+					(void **)pending, *nb_pending);
+			*nb_pending = 0;
+		}
+
+		pending[(*nb_pending)++] = m;
+	}
+}
+
+/**
+ * Size of the array holding mbufs from the same mempool pending to be freed
+ * in bulk.
+ */
+#define RTE_PKTMBUF_FREE_PENDING_SZ 64
+
+/* Free a bulk of packet mbufs back into their original mempools. */
+void rte_pktmbuf_free_bulk(struct rte_mbuf **mbufs, unsigned int count)
+{
+	struct rte_mbuf *m, *m_next, *pending[RTE_PKTMBUF_FREE_PENDING_SZ];
+	unsigned int idx, nb_pending = 0;
+
+	for (idx = 0; idx < count; idx++) {
+		m = mbufs[idx];
+		if (unlikely(m == NULL))
+			continue;
+
+		__rte_mbuf_sanity_check(m, 1);
+
+		do {
+			m_next = m->next;
+			__rte_pktmbuf_free_seg_via_array(m,
+					pending, &nb_pending,
+					RTE_PKTMBUF_FREE_PENDING_SZ);
+			m = m_next;
+		} while (m != NULL);
+	}
+
+	if (nb_pending > 0)
+		rte_mempool_put_bulk(pending[0]->pool, (void **)pending, nb_pending);
+}
+
 /* Creates a shallow copy of mbuf */
 struct rte_mbuf *
 rte_pktmbuf_clone(struct rte_mbuf *md, struct rte_mempool *mp)
diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index fb0849ac1..b1a92b17a 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -1914,6 +1914,21 @@ static inline void rte_pktmbuf_free(struct rte_mbuf *m)
 	}
 }
 
+/**
+ * Free a bulk of packet mbufs back into their original mempools.
+ *
+ * Free a bulk of mbufs, and all their segments in case of chained buffers.
+ * Each segment is added back into its original mempool.
+ *
+ *  @param mbufs
+ *    Array of pointers to packet mbufs.
+ *    The array may contain NULL pointers.
+ *  @param count
+ *    Array size.
+ */
+__rte_experimental
+void rte_pktmbuf_free_bulk(struct rte_mbuf **mbufs, unsigned int count);
+
 /**
  * Create a "clone" of the given packet mbuf.
  *
diff --git a/lib/librte_mbuf/rte_mbuf_version.map b/lib/librte_mbuf/rte_mbuf_version.map
index 519fead35..9a2a7b101 100644
--- a/lib/librte_mbuf/rte_mbuf_version.map
+++ b/lib/librte_mbuf/rte_mbuf_version.map
@@ -58,6 +58,7 @@ EXPERIMENTAL {
 	global:
 
 	rte_mbuf_check;
+	rte_pktmbuf_free_bulk;
 	rte_pktmbuf_copy;
 
 } DPDK_18.08;
-- 
2.17.1

[dpdk-dev] [PATCH v9 2/2] mbuf: add unit test for bulk alloc/free functions

[Morten Brørup]

Add unit test for functions for allocating and freeing a bulk of mbufs.

Signed-off-by: Morten Brørup <mb@smartsharesystems.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>

---

v9:
* Fix a typo in a description.
* In the unit test, make chain length a #define and add a few
  RTE_BUILD_BUG_ON().
* The unit test prints when allocating the mbuf pools for the bulk tests.
  Also print when freeing them.
v8:
* Add unit test, covering both bulk alloc and bulk free.
v7:
* Squash multiple modifications into one.
v6:
* Remove __rte_always_inline from static function.
  The compiler will inline anyway.
v5:
* Rename variables from "free" to "pending" for improved readability.
* Add prefix __ to rte_pktmbuf_free_seg_via_array().
* Add array size parameter to __rte_pktmbuf_free_seg_via_array().
  The compiler will optimize the parameter away anyway.
* Add description to __rte_pktmbuf_free_seg_via_array().
* Minor description updates.
v4:
* Mark as experimental by adding __rte_experimental.
* Add function to experimental section of map file.
* Fix source code formatting regarding pointer to pointer.
* Squash multiple modifications into one.
v3:
* Bugfix: Handle pakets with multiple segments.
* Add inline helper function, mainly for readability.
* Fix source code formatting regarding indentation.
v2:
* Function is not inline.
* Optimize to free multible mbufs belonging to the same mempool in
  bulk. Inspired by ixgbe_tx_free_bufs(), but allowing NULL pointers
  in the array, just like rte_pktmbuf_free() can take a NULL pointer.
* Use unsigned int instead of unsigned. Passes checkpatch, but
  mismatches the original coding style of the modified files.
* Fix a typo in the description headline: mempools is plural.
---
 app/test/test_mbuf.c | 179 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 179 insertions(+)

diff --git a/app/test/test_mbuf.c b/app/test/test_mbuf.c
index b9c2b2500..c21ef64c8 100644
--- a/app/test/test_mbuf.c
+++ b/app/test/test_mbuf.c
@@ -12,6 +12,7 @@
 #include <sys/queue.h>
 
 #include <rte_common.h>
+#include <rte_errno.h>
 #include <rte_debug.h>
 #include <rte_log.h>
 #include <rte_memory.h>
@@ -39,6 +40,9 @@
 #define MBUF_TEST_HDR2_LEN      30
 #define MBUF_TEST_ALL_HDRS_LEN  (MBUF_TEST_HDR1_LEN+MBUF_TEST_HDR2_LEN)
 
+/* chain length in bulk test */
+#define CHAIN_LEN 16
+
 /* size of private data for mbuf in pktmbuf_pool2 */
 #define MBUF2_PRIV_SIZE         128
 
@@ -700,6 +704,175 @@ test_pktmbuf_pool(struct rte_mempool *pktmbuf_pool)
 	return ret;
 }
 
+/*
+ * test bulk allocation and bulk free of mbufs
+ */
+static int
+test_pktmbuf_pool_bulk(void)
+{
+	struct rte_mempool *pool = NULL;
+	struct rte_mempool *pool2 = NULL;
+	unsigned int i;
+	struct rte_mbuf *m;
+	struct rte_mbuf *mbufs[NB_MBUF];
+	int ret = 0;
+
+	/* We cannot use the preallocated mbuf pools because their caches
+	 * prevent us from bulk allocating all objects in them.
+	 * So we create our own mbuf pools without caches.
+	 */
+	printf("Create mbuf pools for bulk allocation.\n");
+	pool = rte_pktmbuf_pool_create("test_pktmbuf_bulk",
+			NB_MBUF, 0, 0, MBUF_DATA_SIZE, SOCKET_ID_ANY);
+	if (pool == NULL) {
+		printf("rte_pktmbuf_pool_create() failed. rte_errno %d\n",
+		       rte_errno);
+		goto err;
+	}
+	pool2 = rte_pktmbuf_pool_create("test_pktmbuf_bulk2",
+			NB_MBUF, 0, 0, MBUF_DATA_SIZE, SOCKET_ID_ANY);
+	if (pool2 == NULL) {
+		printf("rte_pktmbuf_pool_create() failed. rte_errno %d\n",
+		       rte_errno);
+		goto err;
+	}
+
+	/* Preconditions: Mempools must be full. */
+	if (!(rte_mempool_full(pool) && rte_mempool_full(pool2))) {
+		printf("Test precondition failed: mempools not full\n");
+		goto err;
+	}
+	if (!(rte_mempool_avail_count(pool) == NB_MBUF &&
+			rte_mempool_avail_count(pool2) == NB_MBUF)) {
+		printf("Test precondition failed: mempools: %u+%u != %u+%u",
+		       rte_mempool_avail_count(pool),
+		       rte_mempool_avail_count(pool2),
+		       NB_MBUF, NB_MBUF);
+		goto err;
+	}
+
+	printf("Test single bulk alloc, followed by multiple bulk free.\n");
+
+	/* Bulk allocate all mbufs in the pool, in one go. */
+	ret = rte_pktmbuf_alloc_bulk(pool, mbufs, NB_MBUF);
+	if (ret != 0) {
+		printf("rte_pktmbuf_alloc_bulk() failed: %d\n", ret);
+		goto err;
+	}
+	/* Test that they have been removed from the pool. */
+	if (!rte_mempool_empty(pool)) {
+		printf("mempool not empty\n");
+		goto err;
+	}
+	/* Bulk free all mbufs, in four steps. */
+	RTE_BUILD_BUG_ON(NB_MBUF % 4 != 0);
+	for (i = 0; i < NB_MBUF; i += NB_MBUF / 4) {
+		rte_pktmbuf_free_bulk(&mbufs[i], NB_MBUF / 4);
+		/* Test that they have been returned to the pool. */
+		if (rte_mempool_avail_count(pool) != i + NB_MBUF / 4) {
+			printf("mempool avail count incorrect\n");
+			goto err;
+		}
+	}
+
+	printf("Test multiple bulk alloc, followed by single bulk free.\n");
+
+	/* Bulk allocate all mbufs in the pool, in four steps. */
+	for (i = 0; i < NB_MBUF; i += NB_MBUF / 4) {
+		ret = rte_pktmbuf_alloc_bulk(pool, &mbufs[i], NB_MBUF / 4);
+		if (ret != 0) {
+			printf("rte_pktmbuf_alloc_bulk() failed: %d\n", ret);
+			goto err;
+		}
+	}
+	/* Test that they have been removed from the pool. */
+	if (!rte_mempool_empty(pool)) {
+		printf("mempool not empty\n");
+		goto err;
+	}
+	/* Bulk free all mbufs, in one go. */
+	rte_pktmbuf_free_bulk(mbufs, NB_MBUF);
+	/* Test that they have been returned to the pool. */
+	if (!rte_mempool_full(pool)) {
+		printf("mempool not full\n");
+		goto err;
+	}
+
+	printf("Test bulk free of single long chain.\n");
+
+	/* Bulk allocate all mbufs in the pool, in one go. */
+	ret = rte_pktmbuf_alloc_bulk(pool, mbufs, NB_MBUF);
+	if (ret != 0) {
+		printf("rte_pktmbuf_alloc_bulk() failed: %d\n", ret);
+		goto err;
+	}
+	/* Create a long mbuf chain. */
+	for (i = 1; i < NB_MBUF; i++) {
+		ret = rte_pktmbuf_chain(mbufs[0], mbufs[i]);
+		if (ret != 0) {
+			printf("rte_pktmbuf_chain() failed: %d\n", ret);
+			goto err;
+		}
+		mbufs[i] = NULL;
+	}
+	/* Free the mbuf chain containing all the mbufs. */
+	rte_pktmbuf_free_bulk(mbufs, 1);
+	/* Test that they have been returned to the pool. */
+	if (!rte_mempool_full(pool)) {
+		printf("mempool not full\n");
+		goto err;
+	}
+
+	printf("Test bulk free of multiple chains using multiple pools.\n");
+
+	/* Create mbuf chains containing mbufs from different pools. */
+	RTE_BUILD_BUG_ON(CHAIN_LEN % 2 != 0);
+	RTE_BUILD_BUG_ON(NB_MBUF % (CHAIN_LEN / 2) != 0);
+	for (i = 0; i < NB_MBUF * 2; i++) {
+		m = rte_pktmbuf_alloc((i & 4) ? pool2 : pool);
+		if (m == NULL) {
+			printf("rte_pktmbuf_alloc() failed (%u)\n", i);
+			goto err;
+		}
+		if ((i % CHAIN_LEN) == 0)
+			mbufs[i / CHAIN_LEN] = m;
+		else
+			rte_pktmbuf_chain(mbufs[i / CHAIN_LEN], m);
+	}
+	/* Test that both pools have been emptied. */
+	if (!(rte_mempool_empty(pool) && rte_mempool_empty(pool2))) {
+		printf("mempools not empty\n");
+		goto err;
+	}
+	/* Free one mbuf chain. */
+	rte_pktmbuf_free_bulk(mbufs, 1);
+	/* Test that the segments have been returned to the pools. */
+	if (!(rte_mempool_avail_count(pool) == CHAIN_LEN / 2 &&
+			rte_mempool_avail_count(pool2) == CHAIN_LEN / 2)) {
+		printf("all segments of first mbuf have not been returned\n");
+		goto err;
+	}
+	/* Free the remaining mbuf chains. */
+	rte_pktmbuf_free_bulk(&mbufs[1], NB_MBUF * 2 / CHAIN_LEN - 1);
+	/* Test that they have been returned to the pools. */
+	if (!(rte_mempool_full(pool) && rte_mempool_full(pool2))) {
+		printf("mempools not full\n");
+		goto err;
+	}
+
+	ret = 0;
+	goto done;
+
+err:
+	ret = -1;
+
+done:
+	printf("Free mbuf pools for bulk allocation.\n");
+	rte_mempool_free(pool);
+	rte_mempool_free(pool2);
+	return ret;
+}
+
 /*
  * test that the pointer to the data on a packet mbuf is set properly
  */
@@ -1317,6 +1490,12 @@ test_mbuf(void)
 		goto err;
 	}
 
+	/* test bulk mbuf alloc and free */
+	if (test_pktmbuf_pool_bulk() < 0) {
+		printf("test_pktmbuf_pool_bulk() failed\n");
+		goto err;
+	}
+
 	/* test that the pointer to the data on a packet mbuf is set properly */
 	if (test_pktmbuf_pool_ptr(pktmbuf_pool) < 0) {
 		printf("test_pktmbuf_pool_ptr() failed\n");
-- 
2.17.1

Re: [dpdk-dev] [PATCH v9 0/2] mbuf: add bulk free function

[Thomas Monjalon]

23/10/2019 12:11, Morten Brørup:
> Add function for freeing a bulk of mbufs.
> 
> Add unit test for functions for allocating and freeing a bulk of mbufs.
> 
> Morten Brørup (2):
>   mbuf: add bulk free function
>   mbuf: add unit test for bulk alloc/free functions

Applied, thanks