Data path performance can benefit if the PMD knows which memory it will
need to handle in advance, before the first mbuf is sent to the PMD.
It is impractical, however, to consider all allocated memory for this
purpose. Most often mbuf memory comes from mempools that can come and
go. PMD can enumerate existing mempools on device start, but it also
needs to track creation and destruction of mempools after the forwarding
starts but before an mbuf from the new mempool is sent to the device.
Add an API to register callback for mempool life cycle events:
* rte_mempool_event_callback_register()
* rte_mempool_event_callback_unregister()
Currently tracked events are:
* RTE_MEMPOOL_EVENT_READY (after populating a mempool)
* RTE_MEMPOOL_EVENT_DESTROY (before freeing a mempool)
Provide a unit test for the new API.
The new API is internal, because it is primarily demanded by PMDs that
may need to deal with any mempools and do not control their creation,
while an application, on the other hand, knows which mempools it creates
and doesn't care about internal mempools PMDs might create.
Signed-off-by: Dmitry Kozlyuk <dkozl...@nvidia.com>
Acked-by: Matan Azrad <ma...@nvidia.com>
---
app/test/test_mempool.c | 209 ++++++++++++++++++++++++++++++++++++++
lib/mempool/rte_mempool.c | 137 +++++++++++++++++++++++++
lib/mempool/rte_mempool.h | 61 +++++++++++
lib/mempool/version.map | 8 ++
4 files changed, 415 insertions(+)
diff --git a/app/test/test_mempool.c b/app/test/test_mempool.c
index 7675a3e605..bc0cc9ed48 100644
--- a/app/test/test_mempool.c
+++ b/app/test/test_mempool.c
@@ -14,6 +14,7 @@
#include <rte_common.h>
#include <rte_log.h>
#include <rte_debug.h>
+#include <rte_errno.h>
#include <rte_memory.h>
#include <rte_launch.h>
#include <rte_cycles.h>
@@ -471,6 +472,206 @@ test_mp_mem_init(struct rte_mempool *mp,
data->ret = 0;
}
+struct test_mempool_events_data {
+ struct rte_mempool *mp;
+ enum rte_mempool_event event;
+ bool invoked;
+};
+
+static void
+test_mempool_events_cb(enum rte_mempool_event event,
+ struct rte_mempool *mp, void *user_data)
+{
+ struct test_mempool_events_data *data = user_data;
+
+ data->mp = mp;
+ data->event = event;
+ data->invoked = true;
+}
+
+static int
+test_mempool_events(int (*populate)(struct rte_mempool *mp))
+{
+ static const size_t CB_NUM = 3;
+ static const size_t MP_NUM = 2;
+
+ struct test_mempool_events_data data[CB_NUM];
+ struct rte_mempool *mp[MP_NUM];
+ char name[RTE_MEMPOOL_NAMESIZE];
+ size_t i, j;
+ int ret;
+
+ for (i = 0; i < CB_NUM; i++) {
+ ret = rte_mempool_event_callback_register
+ (test_mempool_events_cb, &data[i]);
+ RTE_TEST_ASSERT_EQUAL(ret, 0, "Failed to register the callback
%zu: %s",
+ i, rte_strerror(rte_errno));
+ }
+ ret = rte_mempool_event_callback_unregister(test_mempool_events_cb, mp);
+ RTE_TEST_ASSERT_NOT_EQUAL(ret, 0, "Unregistered a non-registered
callback");
+ /* NULL argument has no special meaning in this API. */
+ ret = rte_mempool_event_callback_unregister(test_mempool_events_cb,
+ NULL);
+ RTE_TEST_ASSERT_NOT_EQUAL(ret, 0, "Unregistered a non-registered
callback with NULL argument");
+
+ /* Create mempool 0 that will be observed by all callbacks. */
+ memset(&data, 0, sizeof(data));
+ strcpy(name, "empty0");
+ mp[0] = rte_mempool_create_empty(name, MEMPOOL_SIZE,
+ MEMPOOL_ELT_SIZE, 0, 0,
+ SOCKET_ID_ANY, 0);
+ RTE_TEST_ASSERT_NOT_NULL(mp[0], "Cannot create mempool %s: %s",
+ name, rte_strerror(rte_errno));
+ for (j = 0; j < CB_NUM; j++)
+ RTE_TEST_ASSERT_EQUAL(data[j].invoked, false,
+ "Callback %zu invoked on %s mempool
creation",
+ j, name);
+
+ rte_mempool_set_ops_byname(mp[0], rte_mbuf_best_mempool_ops(), NULL);
+ ret = populate(mp[0]);
+ RTE_TEST_ASSERT_EQUAL(ret, (int)mp[0]->size, "Failed to populate
mempool %s: %s",
+ name, rte_strerror(rte_errno));
+ for (j = 0; j < CB_NUM; j++) {
+ RTE_TEST_ASSERT_EQUAL(data[j].invoked, true,
+ "Callback %zu not invoked on mempool %s
population",
+ j, name);
+ RTE_TEST_ASSERT_EQUAL(data[j].event,
+ RTE_MEMPOOL_EVENT_READY,
+ "Wrong callback invoked, expected
READY");
+ RTE_TEST_ASSERT_EQUAL(data[j].mp, mp[0],
+ "Callback %zu invoked for a wrong
mempool instead of %s",
+ j, name);
+ }
+
+ /* Check that unregistered callback 0 observes no events. */
+ ret = rte_mempool_event_callback_unregister(test_mempool_events_cb,
+ &data[0]);
+ RTE_TEST_ASSERT_EQUAL(ret, 0, "Failed to unregister callback 0: %s",
+ rte_strerror(rte_errno));
+ memset(&data, 0, sizeof(data));
+ strcpy(name, "empty1");
+ mp[1] = rte_mempool_create_empty(name, MEMPOOL_SIZE,
+ MEMPOOL_ELT_SIZE, 0, 0,
+ SOCKET_ID_ANY, 0);
+ RTE_TEST_ASSERT_NOT_NULL(mp[1], "Cannot create mempool %s: %s",
+ name, rte_strerror(rte_errno));
+ rte_mempool_set_ops_byname(mp[1], rte_mbuf_best_mempool_ops(), NULL);
+ ret = populate(mp[1]);
+ RTE_TEST_ASSERT_EQUAL(ret, (int)mp[1]->size, "Failed to populate
mempool %s: %s",
+ name, rte_strerror(rte_errno));
+ RTE_TEST_ASSERT_EQUAL(data[0].invoked, false,
+ "Unregistered callback 0 invoked on %s mempool
populaton",
+ name);
+
+ for (i = 0; i < MP_NUM; i++) {
+ memset(&data, 0, sizeof(data));
+ sprintf(name, "empty%zu", i);
+ rte_mempool_free(mp[i]);
+ for (j = 1; j < CB_NUM; j++) {
+ RTE_TEST_ASSERT_EQUAL(data[j].invoked, true,
+ "Callback %zu not invoked on
mempool %s destruction",
+ j, name);
+ RTE_TEST_ASSERT_EQUAL(data[j].event,
+ RTE_MEMPOOL_EVENT_DESTROY,
+ "Wrong callback invoked, expected
DESTROY");
+ RTE_TEST_ASSERT_EQUAL(data[j].mp, mp[i],
+ "Callback %zu invoked for a wrong
mempool instead of %s",
+ j, name);
+ }
+ RTE_TEST_ASSERT_EQUAL(data[0].invoked, false,
+ "Unregistered callback 0 invoked on %s
mempool destruction",
+ name);
+ }
+
+ for (j = 1; j < CB_NUM; j++) {
+ ret = rte_mempool_event_callback_unregister
+ (test_mempool_events_cb, &data[j]);
+ RTE_TEST_ASSERT_EQUAL(ret, 0, "Failed to unregister the
callback %zu: %s",
+ j, rte_strerror(rte_errno));
+ }
+ return 0;
+}
+
+struct test_mempool_events_safety_data {
+ bool invoked;
+ int (*api_func)(rte_mempool_event_callback *func, void *user_data);
+ rte_mempool_event_callback *cb_func;
+ void *cb_user_data;
+ int ret;
+};
+
+static void
+test_mempool_events_safety_cb(enum rte_mempool_event event,
+ struct rte_mempool *mp, void *user_data)
+{
+ struct test_mempool_events_safety_data *data = user_data;
+
+ RTE_SET_USED(event);
+ RTE_SET_USED(mp);
+ data->invoked = true;
+ data->ret = data->api_func(data->cb_func, data->cb_user_data);
+}
+
+static int
+test_mempool_events_safety(void)
+{
+ struct test_mempool_events_data data;
+ struct test_mempool_events_safety_data sdata[2];
+ struct rte_mempool *mp;
+ size_t i;
+ int ret;
+
+ /* removes itself */
+ sdata[0].api_func = rte_mempool_event_callback_unregister;
+ sdata[0].cb_func = test_mempool_events_safety_cb;
+ sdata[0].cb_user_data = &sdata[0];
+ sdata[0].ret = -1;
+ rte_mempool_event_callback_register(test_mempool_events_safety_cb,
+ &sdata[0]);
+ /* inserts a callback after itself */
+ sdata[1].api_func = rte_mempool_event_callback_register;
+ sdata[1].cb_func = test_mempool_events_cb;
+ sdata[1].cb_user_data = &data;
+ sdata[1].ret = -1;
+ rte_mempool_event_callback_register(test_mempool_events_safety_cb,
+ &sdata[1]);
+
+ mp = rte_mempool_create_empty("empty", MEMPOOL_SIZE,
+ MEMPOOL_ELT_SIZE, 0, 0,
+ SOCKET_ID_ANY, 0);
+ RTE_TEST_ASSERT_NOT_NULL(mp, "Cannot create mempool: %s",
+ rte_strerror(rte_errno));
+ memset(&data, 0, sizeof(data));
+ ret = rte_mempool_populate_default(mp);
+ RTE_TEST_ASSERT_EQUAL(ret, (int)mp->size, "Failed to populate mempool:
%s",
+ rte_strerror(rte_errno));
+
+ RTE_TEST_ASSERT_EQUAL(sdata[0].ret, 0, "Callback failed to unregister
itself: %s",
+ rte_strerror(rte_errno));
+ RTE_TEST_ASSERT_EQUAL(sdata[1].ret, 0, "Failed to insert a new
callback: %s",
+ rte_strerror(rte_errno));
+ RTE_TEST_ASSERT_EQUAL(data.invoked, false,
+ "Inserted callback is invoked on mempool
population");
+
+ memset(&data, 0, sizeof(data));
+ sdata[0].invoked = false;
+ rte_mempool_free(mp);
+ RTE_TEST_ASSERT_EQUAL(sdata[0].invoked, false,
+ "Callback that unregistered itself was called");
+ RTE_TEST_ASSERT_EQUAL(sdata[1].ret, -EEXIST,
+ "New callback inserted twice");
+ RTE_TEST_ASSERT_EQUAL(data.invoked, true,
+ "Inserted callback is not invoked on mempool
destruction");
+
+ /* cleanup, don't care which callbacks are already removed */
+ rte_mempool_event_callback_unregister(test_mempool_events_cb, &data);
+ for (i = 0; i < RTE_DIM(sdata); i++)
+ rte_mempool_event_callback_unregister
+ (test_mempool_events_safety_cb,
+ &sdata[i]);
+ return 0;
+}
+
static int
test_mempool(void)
{
@@ -645,6 +846,14 @@ test_mempool(void)
if (test_mempool_basic(default_pool, 1) < 0)
GOTO_ERR(ret, err);
+ /* test mempool event callbacks */
+ if (test_mempool_events(rte_mempool_populate_default) < 0)
+ GOTO_ERR(ret, err);
+ if (test_mempool_events(rte_mempool_populate_anon) < 0)
+ GOTO_ERR(ret, err);
+ if (test_mempool_events_safety() < 0)
+ GOTO_ERR(ret, err);
+
rte_mempool_list_dump(stdout);
ret = 0;
diff --git a/lib/mempool/rte_mempool.c b/lib/mempool/rte_mempool.c
index c5f859ae71..51c0ba2931 100644
--- a/lib/mempool/rte_mempool.c
+++ b/lib/mempool/rte_mempool.c
@@ -42,6 +42,18 @@ static struct rte_tailq_elem rte_mempool_tailq = {
};
EAL_REGISTER_TAILQ(rte_mempool_tailq)
+TAILQ_HEAD(mempool_callback_list, rte_tailq_entry);
+
+static struct rte_tailq_elem callback_tailq = {
+ .name = "RTE_MEMPOOL_CALLBACK",
+};
+EAL_REGISTER_TAILQ(callback_tailq)
+
+/* Invoke all registered mempool event callbacks. */
+static void
+mempool_event_callback_invoke(enum rte_mempool_event event,
+ struct rte_mempool *mp);
+
#define CACHE_FLUSHTHRESH_MULTIPLIER 1.5
#define CALC_CACHE_FLUSHTHRESH(c) \
((typeof(c))((c) * CACHE_FLUSHTHRESH_MULTIPLIER))
@@ -360,6 +372,10 @@ rte_mempool_populate_iova(struct rte_mempool *mp, char
*vaddr,
STAILQ_INSERT_TAIL(&mp->mem_list, memhdr, next);
mp->nb_mem_chunks++;
+ /* Report the mempool as ready only when fully populated. */
+ if (mp->populated_size >= mp->size)
+ mempool_event_callback_invoke(RTE_MEMPOOL_EVENT_READY, mp);
+
rte_mempool_trace_populate_iova(mp, vaddr, iova, len, free_cb, opaque);
return i;
@@ -722,6 +738,7 @@ rte_mempool_free(struct rte_mempool *mp)
}
rte_mcfg_tailq_write_unlock();
+ mempool_event_callback_invoke(RTE_MEMPOOL_EVENT_DESTROY, mp);
rte_mempool_trace_free(mp);
rte_mempool_free_memchunks(mp);
rte_mempool_ops_free(mp);
@@ -1343,3 +1360,123 @@ void rte_mempool_walk(void (*func)(struct rte_mempool
*, void *),
rte_mcfg_mempool_read_unlock();
}
+
+struct mempool_callback {
+ rte_mempool_event_callback *func;
+ void *user_data;
+};
+
+static void
+mempool_event_callback_invoke(enum rte_mempool_event event,
+ struct rte_mempool *mp)
+{
+ struct mempool_callback_list *list;
+ struct rte_tailq_entry *te;
+ void *tmp_te;
+
+ rte_mcfg_tailq_read_lock();
+ list = RTE_TAILQ_CAST(callback_tailq.head, mempool_callback_list);
+ RTE_TAILQ_FOREACH_SAFE(te, list, next, tmp_te) {
+ struct mempool_callback *cb = te->data;
+ rte_mcfg_tailq_read_unlock();
+ cb->func(event, mp, cb->user_data);
+ rte_mcfg_tailq_read_lock();
+ }
+ rte_mcfg_tailq_read_unlock();
+}
+
+int
+rte_mempool_event_callback_register(rte_mempool_event_callback *func,
+ void *user_data)
+{
+ struct mempool_callback_list *list;
+ struct rte_tailq_entry *te = NULL;
+ struct mempool_callback *cb;
+ void *tmp_te;
+ int ret;
+
+ if (func == NULL) {
+ rte_errno = EINVAL;
+ return -rte_errno;
+ }
+
+ rte_mcfg_mempool_read_lock();
+ rte_mcfg_tailq_write_lock();
+
+ list = RTE_TAILQ_CAST(callback_tailq.head, mempool_callback_list);
+ RTE_TAILQ_FOREACH_SAFE(te, list, next, tmp_te) {
+ struct mempool_callback *cb =
+ (struct mempool_callback *)te->data;
+ if (cb->func == func && cb->user_data == user_data) {
+ ret = -EEXIST;
+ goto exit;
+ }
+ }
+
+ te = rte_zmalloc("MEMPOOL_TAILQ_ENTRY", sizeof(*te), 0);
+ if (te == NULL) {
+ RTE_LOG(ERR, MEMPOOL,
+ "Cannot allocate event callback tailq entry!\n");
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ cb = rte_malloc("MEMPOOL_EVENT_CALLBACK", sizeof(*cb), 0);
+ if (cb == NULL) {
+ RTE_LOG(ERR, MEMPOOL,
+ "Cannot allocate event callback!\n");
+ rte_free(te);
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ cb->func = func;
+ cb->user_data = user_data;
+ te->data = cb;
+ TAILQ_INSERT_TAIL(list, te, next);
+ ret = 0;
+
+exit:
+ rte_mcfg_tailq_write_unlock();
+ rte_mcfg_mempool_read_unlock();
+ rte_errno = -ret;
+ return ret;
+}
+
+int
+rte_mempool_event_callback_unregister(rte_mempool_event_callback *func,
+ void *user_data)
+{
+ struct mempool_callback_list *list;
+ struct rte_tailq_entry *te = NULL;
+ struct mempool_callback *cb;
+ int ret;
+
+ if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
+ rte_errno = EPERM;
+ return -1;
+ }
+
+ rte_mcfg_mempool_read_lock();
+ rte_mcfg_tailq_write_lock();
+ ret = -ENOENT;
+ list = RTE_TAILQ_CAST(callback_tailq.head, mempool_callback_list);
+ TAILQ_FOREACH(te, list, next) {
+ cb = (struct mempool_callback *)te->data;
+ if (cb->func == func && cb->user_data == user_data)
+ break;
+ }
+ if (te != NULL) {
+ TAILQ_REMOVE(list, te, next);
+ ret = 0;
+ }
+ rte_mcfg_tailq_write_unlock();
+ rte_mcfg_mempool_read_unlock();
+
+ if (ret == 0) {
+ rte_free(te);
+ rte_free(cb);
+ }
+ rte_errno = -ret;
+ return ret;
+}
diff --git a/lib/mempool/rte_mempool.h b/lib/mempool/rte_mempool.h
index f57ecbd6fc..663123042f 100644
--- a/lib/mempool/rte_mempool.h
+++ b/lib/mempool/rte_mempool.h
@@ -1774,6 +1774,67 @@ void rte_mempool_walk(void (*func)(struct rte_mempool *,
void *arg),
int
rte_mempool_get_page_size(struct rte_mempool *mp, size_t *pg_sz);
+/**
+ * Mempool event type.
+ * @internal
+ */
+enum rte_mempool_event {
+ /** Occurs after a mempool is successfully populated. */
+ RTE_MEMPOOL_EVENT_READY = 0,
+ /** Occurs before destruction of a mempool begins. */
+ RTE_MEMPOOL_EVENT_DESTROY = 1,
+};
+
+/**
+ * @internal
+ * Mempool event callback.
+ *
+ * rte_mempool_event_callback_register() may be called from within the
callback,
+ * but the callbacks registered this way will not be invoked for the same
event.
+ * rte_mempool_event_callback_unregister() may only be safely called
+ * to remove the running callback.
+ */
+typedef void (rte_mempool_event_callback)(
+ enum rte_mempool_event event,
+ struct rte_mempool *mp,
+ void *user_data);
+
+/**
+ * @internal
+ * Register a callback invoked on mempool life cycle event.
+ * Callbacks will be invoked in the process that creates the mempool.
+ *
+ * @param func
+ * Callback function.
+ * @param user_data
+ * User data.
+ *
+ * @return
+ * 0 on success, negative on failure and rte_errno is set.
+ */
+__rte_internal
+int
+rte_mempool_event_callback_register(rte_mempool_event_callback *func,
+ void *user_data);
+
+/**
+ * @internal
+ * Unregister a callback added with rte_mempool_event_callback_register().
+ * @p func and @p user_data must exactly match registration parameters.
+ *
+ * @param func
+ * Callback function.
+ * @param user_data
+ * User data.
+ *
+ * @return
+ * 0 on success, negative on failure and rte_errno is set.
+ */
+__rte_internal
+int
+rte_mempool_event_callback_unregister(rte_mempool_event_callback *func,
+ void *user_data);
+
#ifdef __cplusplus
}
#endif
diff --git a/lib/mempool/version.map b/lib/mempool/version.map
index 9f77da6fff..1b7d7c5456 100644
--- a/lib/mempool/version.map
+++ b/lib/mempool/version.map
@@ -64,3 +64,11 @@ EXPERIMENTAL {
__rte_mempool_trace_ops_free;
__rte_mempool_trace_set_ops_byname;
};
+
+INTERNAL {
+ global:
+
+ # added in 21.11
+ rte_mempool_event_callback_register;
+ rte_mempool_event_callback_unregister;
+};
--
2.25.1
