ctdb: Adding memory pool for queue callback

The received packet is copied into a newly allocated memory chunk for further
processing by the assigned callback. Once this is done, the memory is free'd.
This is repeated for each received packet making the memory allocation / free
an expensive task. To optimize this process, a memory pool is defined which
is sized identically to the queue's buffer.
During tests it could be seen that more than 95% of all messages were sized
below the standard buffer_size of 1k.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Reviewed-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Christof Schmitt <cs@samba.org>

Autobuild-User(master): Christof Schmitt <cs@samba.org>
Autobuild-Date(master): Fri Dec  7 23:27:16 CET 2018 on sn-devel-144

1 files changed, 8 insertions, 1 deletions

diff --git a/ctdb/common/ctdb_io.c b/ctdb/common/ctdb_io.c
index 5bed7a61b31..d86540762ea 100644
--- a/ctdb/common/ctdb_io.c
+++ b/ctdb/common/ctdb_io.c
@@ -65,6 +65,7 @@ struct ctdb_queue {
 	size_t alignment;
 	void *private_data;
 	ctdb_queue_cb_fn_t callback;
+	TALLOC_CTX *data_pool;
 	const char *name;
 	uint32_t buffer_size;
 };
@@ -115,7 +116,7 @@ static void queue_process(struct ctdb_queue *queue)
 	}
 
 	/* Extract complete packet */
-	data = talloc_memdup(queue,
+	data = talloc_memdup(queue->data_pool,
 			     queue->buffer.data + queue->buffer.offset,
 			     pkt_size);
 
@@ -479,5 +480,11 @@ struct ctdb_queue *ctdb_queue_setup(struct ctdb_context *ctdb,
 		queue->buffer_size = 1024;
 	}
 
+	queue->data_pool = talloc_pool(queue, queue->buffer_size);
+	if (queue->data_pool == NULL) {
+		TALLOC_FREE(queue);
+		return NULL;
+	}
+
 	return queue;
 }