[2/2] mempool: use shared memzone for rte_mempool_ops
diff mbox series

Message ID 1586429580-6990-2-git-send-email-xiangxia.m.yue@gmail.com
State Superseded, archived
Delegated to: David Marchand
Headers show
Series
  • [1/2] eal: introduce last-init queue for libraries initialization
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ci/checkpatch warning coding style issues

Commit Message

Tonghao Zhang April 9, 2020, 10:53 a.m. UTC
From: Tonghao Zhang <xiangxia.m.yue@gmail.com>

The order of mempool initiation affects mempool index in the
rte_mempool_ops_table. For example, when building APPs with:

$ gcc -lrte_mempool_bucket -lrte_mempool_ring ...

The "bucket" mempool will be registered firstly, and its index
in table is 0 while the index of "ring" mempool is 1. DPDK
uses the mk/rte.app.mk to build APPs, and others, for example,
Open vSwitch, use the libdpdk.a or libdpdk.so to build it.
The mempool lib linked in dpdk and Open vSwitch is different.

The mempool can be used between primary and secondary process,
such as dpdk-pdump and pdump-pmd/Open vSwitch(pdump enabled).
There will be a crash because dpdk-pdump creates the "ring_mp_mc"
ring which index in table is 0, but the index of "bucket" ring
is 0 in Open vSwitch. If Open vSwitch use the index 0 to get
mempool ops and malloc memory from mempool. The crash will occur:

    bucket_dequeue (access null and crash)
    rte_mempool_get_ops (should get "ring_mp_mc",
                         but get "bucket" mempool)
    rte_mempool_ops_dequeue_bulk
    ...
    rte_pktmbuf_alloc
    rte_pktmbuf_copy
    pdump_copy
    pdump_rx
    rte_eth_rx_burst

To avoid the crash, there are some solution:
* constructor priority: Different mempool uses different
  priority in RTE_INIT, but it's not easy to maintain.

* change mk/rte.app.mk: Change the order in mk/rte.app.mk to
  be same as libdpdk.a/libdpdk.so, but when adding a new mempool
  driver in future, we must make sure the order.

* register mempool orderly: Sort the mempool when registering,
  so the lib linked will not affect the index in mempool table.
  but the number of mempool libraries may be different.

* shared memzone: The primary process allocates a struct in
  shared memory named memzone, When we register a mempool ops,
  we first get a name and id from the shared struct: with the lock held,
  lookup for the registered name and return its index, else
  get the last id and copy the name in the struct.

previous discussion:
https://mails.dpdk.org/archives/dev/2020-March/159354.html

Suggested-by: Olivier Matz <olivier.matz@6wind.com>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
---
 lib/librte_mempool/rte_mempool.h     | 22 ++++++++-
 lib/librte_mempool/rte_mempool_ops.c | 89 ++++++++++++++++++++++++++++--------
 2 files changed, 90 insertions(+), 21 deletions(-)

Patch
diff mbox series

diff --git a/lib/librte_mempool/rte_mempool.h b/lib/librte_mempool/rte_mempool.h
index c90cf31..fdd1057 100644
--- a/lib/librte_mempool/rte_mempool.h
+++ b/lib/librte_mempool/rte_mempool.h
@@ -50,6 +50,7 @@ 
 #include <rte_ring.h>
 #include <rte_memcpy.h>
 #include <rte_common.h>
+#include <rte_last_init.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -678,7 +679,6 @@  struct rte_mempool_ops {
  */
 struct rte_mempool_ops_table {
 	rte_spinlock_t sl;     /**< Spinlock for add/delete. */
-	uint32_t num_ops;      /**< Number of used ops structs in the table. */
 	/**
 	 * Storage for all possible ops structs.
 	 */
@@ -910,6 +910,23 @@  int rte_mempool_ops_get_info(const struct rte_mempool *mp,
  */
 int rte_mempool_register_ops(const struct rte_mempool_ops *ops);
 
+struct rte_mempool_shared_ops {
+	size_t num_mempool_ops;
+	struct {
+		char name[RTE_MEMPOOL_OPS_NAMESIZE];
+	} mempool_ops[RTE_MEMPOOL_MAX_OPS_IDX];
+
+	rte_spinlock_t mempool;
+};
+
+static inline int
+rte_mempool_register_ops_cb(const void *arg)
+{
+	const struct rte_mempool_ops *h = (const struct rte_mempool_ops *)arg;
+
+	return rte_mempool_register_ops(h);
+}
+
 /**
  * Macro to statically register the ops of a mempool handler.
  * Note that the rte_mempool_register_ops fails silently here when
@@ -918,7 +935,8 @@  int rte_mempool_ops_get_info(const struct rte_mempool *mp,
 #define MEMPOOL_REGISTER_OPS(ops)				\
 	RTE_INIT(mp_hdlr_init_##ops)				\
 	{							\
-		rte_mempool_register_ops(&ops);			\
+		rte_last_init_register(rte_mempool_register_ops_cb, \
+				       (const void *)&ops);	\
 	}
 
 /**
diff --git a/lib/librte_mempool/rte_mempool_ops.c b/lib/librte_mempool/rte_mempool_ops.c
index 22c5251..48aa999 100644
--- a/lib/librte_mempool/rte_mempool_ops.c
+++ b/lib/librte_mempool/rte_mempool_ops.c
@@ -14,43 +14,95 @@ 
 /* indirect jump table to support external memory pools. */
 struct rte_mempool_ops_table rte_mempool_ops_table = {
 	.sl =  RTE_SPINLOCK_INITIALIZER,
-	.num_ops = 0
 };
 
-/* add a new ops struct in rte_mempool_ops_table, return its index. */
-int
-rte_mempool_register_ops(const struct rte_mempool_ops *h)
+static int
+rte_mempool_register_shared_ops(const char *name)
 {
-	struct rte_mempool_ops *ops;
-	int16_t ops_index;
+	static bool mempool_shared_ops_inited = false;
+	struct rte_mempool_shared_ops *shared_ops;
+	const struct rte_memzone* mz;
+	uint32_t ops_index = 0;
+
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY &&
+	    !mempool_shared_ops_inited) {
+
+		mz = rte_memzone_reserve("mempool_ops_shared",
+					 sizeof(*shared_ops), 0, 0);
+		if (mz == NULL)
+			return -ENOMEM;
+
+		shared_ops = mz->addr;
+		shared_ops->num_mempool_ops = 0;
+		rte_spinlock_init(&shared_ops->mempool);
+
+		mempool_shared_ops_inited = true;
+	} else {
+		mz = rte_memzone_lookup("mempool_ops_shared");
+		if (mz == NULL)
+			return -ENOMEM;
+
+		shared_ops = mz->addr;
+	}
 
-	rte_spinlock_lock(&rte_mempool_ops_table.sl);
+	rte_spinlock_lock(&shared_ops->mempool);
 
-	if (rte_mempool_ops_table.num_ops >=
-			RTE_MEMPOOL_MAX_OPS_IDX) {
-		rte_spinlock_unlock(&rte_mempool_ops_table.sl);
+	if (shared_ops->num_mempool_ops >= RTE_MEMPOOL_MAX_OPS_IDX) {
+		rte_spinlock_unlock(&shared_ops->mempool);
 		RTE_LOG(ERR, MEMPOOL,
 			"Maximum number of mempool ops structs exceeded\n");
 		return -ENOSPC;
 	}
 
+	while (shared_ops->mempool_ops[ops_index].name[0]) {
+		if(!strcmp(name, shared_ops->mempool_ops[ops_index].name)) {
+			rte_spinlock_unlock(&shared_ops->mempool);
+			return ops_index;
+		}
+
+		ops_index ++;
+	}
+
+	strlcpy(shared_ops->mempool_ops[ops_index].name, name,
+		sizeof(shared_ops->mempool_ops[0].name));
+
+	shared_ops->num_mempool_ops ++;
+
+	rte_spinlock_unlock(&shared_ops->mempool);
+	return ops_index;
+}
+
+/* add a new ops struct in rte_mempool_ops_table, return its index. */
+int
+rte_mempool_register_ops(const struct rte_mempool_ops *h)
+{
+	struct rte_mempool_ops *ops;
+	int16_t ops_index;
+
 	if (h->alloc == NULL || h->enqueue == NULL ||
-			h->dequeue == NULL || h->get_count == NULL) {
-		rte_spinlock_unlock(&rte_mempool_ops_table.sl);
+	    h->dequeue == NULL || h->get_count == NULL) {
 		RTE_LOG(ERR, MEMPOOL,
 			"Missing callback while registering mempool ops\n");
+		rte_errno = EINVAL;
 		return -EINVAL;
 	}
 
 	if (strlen(h->name) >= sizeof(ops->name) - 1) {
-		rte_spinlock_unlock(&rte_mempool_ops_table.sl);
-		RTE_LOG(DEBUG, EAL, "%s(): mempool_ops <%s>: name too long\n",
-				__func__, h->name);
+		RTE_LOG(ERR, MEMPOOL,
+			"The registering  mempool_ops <%s>: name too long\n",
+			h->name);
 		rte_errno = EEXIST;
 		return -EEXIST;
 	}
 
-	ops_index = rte_mempool_ops_table.num_ops++;
+	ops_index = rte_mempool_register_shared_ops(h->name);
+	if (ops_index < 0) {
+		rte_errno = -ops_index;
+		return ops_index;
+	}
+
+	rte_spinlock_lock(&rte_mempool_ops_table.sl);
+
 	ops = &rte_mempool_ops_table.ops[ops_index];
 	strlcpy(ops->name, h->name, sizeof(ops->name));
 	ops->alloc = h->alloc;
@@ -165,9 +217,8 @@  struct rte_mempool_ops_table rte_mempool_ops_table = {
 	if (mp->flags & MEMPOOL_F_POOL_CREATED)
 		return -EEXIST;
 
-	for (i = 0; i < rte_mempool_ops_table.num_ops; i++) {
-		if (!strcmp(name,
-				rte_mempool_ops_table.ops[i].name)) {
+	for (i = 0; i < RTE_MEMPOOL_MAX_OPS_IDX; i++) {
+		if (!strcmp(name, rte_mempool_ops_table.ops[i].name)) {
 			ops = &rte_mempool_ops_table.ops[i];
 			break;
 		}