* [dpdk-dev] [PATCH 1/2] ring: introduce rte_ring_get_memsize()
2014-05-07 11:38 [dpdk-dev] [PATCH 0/2] ring: allow to init a rte_ring outside of an rte_memzone Olivier Matz
@ 2014-05-07 11:38 ` Olivier Matz
2014-05-07 12:35 ` Ananyev, Konstantin
2014-05-07 11:38 ` [dpdk-dev] [PATCH 2/2] ring: introduce rte_ring_init() Olivier Matz
1 sibling, 1 reply; 5+ messages in thread
From: Olivier Matz @ 2014-05-07 11:38 UTC (permalink / raw)
To: dev
Add a function that returns the amount of memory occupied by a rte_ring
structure and its object table. This commit prepares the next one that
will allow to allocate a ring dynamically.
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---
lib/librte_ring/rte_ring.c | 29 ++++++++++++++++++++++-------
lib/librte_ring/rte_ring.h | 16 ++++++++++++++++
2 files changed, 38 insertions(+), 7 deletions(-)
diff --git a/lib/librte_ring/rte_ring.c b/lib/librte_ring/rte_ring.c
index 0d43a55..4aa500f 100644
--- a/lib/librte_ring/rte_ring.c
+++ b/lib/librte_ring/rte_ring.c
@@ -94,6 +94,24 @@ TAILQ_HEAD(rte_ring_list, rte_ring);
/* true if x is a power of 2 */
#define POWEROF2(x) ((((x)-1) & (x)) == 0)
+/* return the size of memory occupied by a ring */
+ssize_t rte_ring_get_memsize(unsigned count)
+{
+ ssize_t sz;
+
+ /* count must be a power of 2 */
+ if ((!POWEROF2(count)) || (count > RTE_RING_SZ_MASK )) {
+ RTE_LOG(ERR, RING,
+ "Requested size is invalid, must be power of 2, and "
+ "do not exceed the size limit %u\n", RTE_RING_SZ_MASK);
+ return -EINVAL;
+ }
+
+ sz = sizeof(struct rte_ring) + count * sizeof(void *);
+ sz = (sz + CACHE_LINE_MASK) & (~CACHE_LINE_MASK);
+ return sz;
+}
+
/* create the ring */
struct rte_ring *
rte_ring_create(const char *name, unsigned count, int socket_id,
@@ -102,7 +120,7 @@ rte_ring_create(const char *name, unsigned count, int socket_id,
char mz_name[RTE_MEMZONE_NAMESIZE];
struct rte_ring *r;
const struct rte_memzone *mz;
- size_t ring_size;
+ ssize_t ring_size;
int mz_flags = 0;
struct rte_ring_list* ring_list = NULL;
@@ -129,16 +147,13 @@ rte_ring_create(const char *name, unsigned count, int socket_id,
return NULL;
}
- /* count must be a power of 2 */
- if ((!POWEROF2(count)) || (count > RTE_RING_SZ_MASK )) {
- rte_errno = EINVAL;
- RTE_LOG(ERR, RING, "Requested size is invalid, must be power of 2, and "
- "do not exceed the size limit %u\n", RTE_RING_SZ_MASK);
+ ring_size = rte_ring_get_memsize(count);
+ if (ring_size < 0) {
+ rte_errno = ring_size;
return NULL;
}
rte_snprintf(mz_name, sizeof(mz_name), "%s%s", RTE_RING_MZ_PREFIX, name);
- ring_size = count * sizeof(void *) + sizeof(struct rte_ring);
rte_rwlock_write_lock(RTE_EAL_TAILQ_RWLOCK);
diff --git a/lib/librte_ring/rte_ring.h b/lib/librte_ring/rte_ring.h
index 775ea79..e8493f2 100644
--- a/lib/librte_ring/rte_ring.h
+++ b/lib/librte_ring/rte_ring.h
@@ -199,6 +199,22 @@ struct rte_ring {
#endif
/**
+ * Calculate the memory size needed for a ring
+ *
+ * This function returns the number of bytes needed for a ring, given
+ * the number of elements in it. This value is the sum of the size of
+ * the structure rte_ring and the size of the memory needed by the
+ * objects pointers. The value is aligned to a cache line size.
+ *
+ * @param count
+ * The number of elements in the ring (must be a power of 2).
+ * @return
+ * - The memory size needed for the ring on success.
+ * - -EINVAL if count is not a power of 2.
+ */
+ssize_t rte_ring_get_memsize(unsigned count);
+
+/**
* Create a new ring named *name* in memory.
*
* This function uses ``memzone_reserve()`` to allocate memory. Its size is
--
1.9.2
^ permalink raw reply [flat|nested] 5+ messages in thread* [dpdk-dev] [PATCH 2/2] ring: introduce rte_ring_init()
2014-05-07 11:38 [dpdk-dev] [PATCH 0/2] ring: allow to init a rte_ring outside of an rte_memzone Olivier Matz
2014-05-07 11:38 ` [dpdk-dev] [PATCH 1/2] ring: introduce rte_ring_get_memsize() Olivier Matz
@ 2014-05-07 11:38 ` Olivier Matz
1 sibling, 0 replies; 5+ messages in thread
From: Olivier Matz @ 2014-05-07 11:38 UTC (permalink / raw)
To: dev
Allow to initialize a ring in an already allocated memory. The rte_ring_create()
function that allocates a ring in a rte_memzone is still available and now uses
the new rte_ring_init() function in order to factorize the code.
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---
lib/librte_ring/rte_ring.c | 63 ++++++++++++++++++++++++++--------------------
lib/librte_ring/rte_ring.h | 51 +++++++++++++++++++++++++++++++++----
2 files changed, 82 insertions(+), 32 deletions(-)
diff --git a/lib/librte_ring/rte_ring.c b/lib/librte_ring/rte_ring.c
index 4aa500f..a65f33e 100644
--- a/lib/librte_ring/rte_ring.c
+++ b/lib/librte_ring/rte_ring.c
@@ -112,18 +112,10 @@ ssize_t rte_ring_get_memsize(unsigned count)
return sz;
}
-/* create the ring */
-struct rte_ring *
-rte_ring_create(const char *name, unsigned count, int socket_id,
- unsigned flags)
+int
+rte_ring_init(struct rte_ring *r, const char *name, unsigned count,
+ unsigned flags)
{
- char mz_name[RTE_MEMZONE_NAMESIZE];
- struct rte_ring *r;
- const struct rte_memzone *mz;
- ssize_t ring_size;
- int mz_flags = 0;
- struct rte_ring_list* ring_list = NULL;
-
/* compilation-time checks */
RTE_BUILD_BUG_ON((sizeof(struct rte_ring) &
CACHE_LINE_MASK) != 0);
@@ -140,11 +132,38 @@ rte_ring_create(const char *name, unsigned count, int socket_id,
CACHE_LINE_MASK) != 0);
#endif
+ /* init the ring structure */
+ memset(r, 0, sizeof(*r));
+ rte_snprintf(r->name, sizeof(r->name), "%s", name);
+ r->flags = flags;
+ r->prod.watermark = count;
+ r->prod.sp_enqueue = !!(flags & RING_F_SP_ENQ);
+ r->cons.sc_dequeue = !!(flags & RING_F_SC_DEQ);
+ r->prod.size = r->cons.size = count;
+ r->prod.mask = r->cons.mask = count-1;
+ r->prod.head = r->cons.head = 0;
+ r->prod.tail = r->cons.tail = 0;
+
+ return 0;
+}
+
+/* create the ring */
+struct rte_ring *
+rte_ring_create(const char *name, unsigned count, int socket_id,
+ unsigned flags)
+{
+ char mz_name[RTE_MEMZONE_NAMESIZE];
+ struct rte_ring *r;
+ const struct rte_memzone *mz;
+ ssize_t ring_size;
+ int mz_flags = 0;
+ struct rte_ring_list* ring_list = NULL;
+
/* check that we have an initialised tail queue */
- if ((ring_list =
+ if ((ring_list =
RTE_TAILQ_LOOKUP_BY_IDX(RTE_TAILQ_RING, rte_ring_list)) == NULL) {
rte_errno = E_RTE_NO_TAILQ;
- return NULL;
+ return NULL;
}
ring_size = rte_ring_get_memsize(count);
@@ -163,26 +182,16 @@ rte_ring_create(const char *name, unsigned count, int socket_id,
mz = rte_memzone_reserve(mz_name, ring_size, socket_id, mz_flags);
if (mz != NULL) {
r = mz->addr;
-
- /* init the ring structure */
- memset(r, 0, sizeof(*r));
- rte_snprintf(r->name, sizeof(r->name), "%s", name);
- r->flags = flags;
- r->prod.watermark = count;
- r->prod.sp_enqueue = !!(flags & RING_F_SP_ENQ);
- r->cons.sc_dequeue = !!(flags & RING_F_SC_DEQ);
- r->prod.size = r->cons.size = count;
- r->prod.mask = r->cons.mask = count-1;
- r->prod.head = r->cons.head = 0;
- r->prod.tail = r->cons.tail = 0;
-
+ /* no need to check return value here, we already checked the
+ * arguments above */
+ rte_ring_init(r, name, count, flags);
TAILQ_INSERT_TAIL(ring_list, r, next);
} else {
r = NULL;
RTE_LOG(ERR, RING, "Cannot reserve memory\n");
}
rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);
-
+
return r;
}
diff --git a/lib/librte_ring/rte_ring.h b/lib/librte_ring/rte_ring.h
index e8493f2..c62e7d7 100644
--- a/lib/librte_ring/rte_ring.h
+++ b/lib/librte_ring/rte_ring.h
@@ -215,13 +215,54 @@ struct rte_ring {
ssize_t rte_ring_get_memsize(unsigned count);
/**
+ * Initialize a ring structure.
+ *
+ * Initialize a ring structure in memory pointed by "r". The size of the
+ * memory area must be large enough to store the ring structure and the
+ * object table. It is advised to use rte_ring_get_memsize() to get the
+ * appropriate size.
+ *
+ * The ring size is set to *count*, which must be a power of two. Water
+ * marking is disabled by default. The real usable ring size is
+ * *count-1* instead of *count* to differentiate a free ring from an
+ * empty ring.
+ *
+ * The ring is not added in RTE_TAILQ_RING global list. Indeed, the
+ * memory given by the caller may not be shareable among dpdk
+ * processes.
+ *
+ * @param r
+ * The pointer to the ring structure followed by the objects table.
+ * @param name
+ * The size of the ring.
+ * @param count
+ * The number of elements in the ring (must be a power of 2).
+ * @param flags
+ * An OR of the following:
+ * - RING_F_SP_ENQ: If this flag is set, the default behavior when
+ * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()``
+ * is "single-producer". Otherwise, it is "multi-producers".
+ * - RING_F_SC_DEQ: If this flag is set, the default behavior when
+ * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()``
+ * is "single-consumer". Otherwise, it is "multi-consumers".
+ * @return
+ * 0 on success, or a negative value on error.
+ */
+int rte_ring_init(struct rte_ring *r, const char *name, unsigned count,
+ unsigned flags);
+
+/**
* Create a new ring named *name* in memory.
*
- * This function uses ``memzone_reserve()`` to allocate memory. Its size is
- * set to *count*, which must be a power of two. Water marking is
- * disabled by default.
- * Note that the real usable ring size is *count-1* instead of
- * *count*.
+ * This function uses ``memzone_reserve()`` to allocate memory. Then it
+ * calls rte_ring_init() to initialize an empty ring.
+ *
+ * The new ring size is set to *count*, which must be a power of
+ * two. Water marking is disabled by default. The real usable ring size
+ * is *count-1* instead of *count* to differentiate a free ring from an
+ * empty ring.
+ *
+ * The ring is added in RTE_TAILQ_RING list.
*
* @param name
* The name of the ring.
--
1.9.2
^ permalink raw reply [flat|nested] 5+ messages in thread