[PATCH v3] net/bonding: another fix to LACP mempool size

[Gaoxiang Liu <gaoxiangliu0@163.com>]

The following log message may appear after a slave is idle(or nearly
idle)
for a few minutes:"PMD: Failed to allocate LACP packet from pool".
And bond mode 4 negotiation may fail.

Problem: All mbufs from a slave' private pool(used exclusively for
transmitting LACPDUs)
have been allocated and are still sitting in the device's tx descriptor
ring and
other cores' mempool caches.

Solution: Ensure that each slave'tx (LACPDU) mempool owns more than
n-tx-queues * n-tx-descriptor + fwd_core_num *
per-core-mmempool-flush-threshold mbufs.

Note that the LACP tx machine fuction is the only code that allocates
from a slave's private pool. It runs in the context of the interrupt
thread, and thus it has no mempool cache of its own.

Signed-off-by: Gaoxiang Liu <liugaoxiang@huawei.com>

---
v2:
* Fixed compile issues.

v3:
* delete duplicate code.
---
 drivers/net/bonding/rte_eth_bond_8023ad.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/bonding/rte_eth_bond_8023ad.c b/drivers/net/bonding/rte_eth_bond_8023ad.c
index ca50583d62..d73038b018 100644
--- a/drivers/net/bonding/rte_eth_bond_8023ad.c
+++ b/drivers/net/bonding/rte_eth_bond_8023ad.c
@@ -1050,6 +1050,7 @@ bond_mode_8023ad_activate_slave(struct rte_eth_dev *bond_dev,
 	uint32_t total_tx_desc;
 	struct bond_tx_queue *bd_tx_q;
 	uint16_t q_id;
+	uint32_t cache_size;
 
 	/* Given slave mus not be in active list */
 	RTE_ASSERT(find_slave_by_id(internals->active_slaves,
@@ -1100,11 +1101,12 @@ bond_mode_8023ad_activate_slave(struct rte_eth_dev *bond_dev,
 		total_tx_desc += bd_tx_q->nb_tx_desc;
 	}
 
+	cache_size = RTE_MEMPOOL_CACHE_MAX_SIZE >= 32 ?
+		32 : RTE_MEMPOOL_CACHE_MAX_SIZE;
+	total_tx_desc = rte_lcore_count() * cache_size * 1.5;
 	snprintf(mem_name, RTE_DIM(mem_name), "slave_port%u_pool", slave_id);
 	port->mbuf_pool = rte_pktmbuf_pool_create(mem_name, total_tx_desc,
-		RTE_MEMPOOL_CACHE_MAX_SIZE >= 32 ?
-			32 : RTE_MEMPOOL_CACHE_MAX_SIZE,
-		0, element_size, socket_id);
+		cache_size, 0, element_size, socket_id);
 
 	/* Any memory allocation failure in initialization is critical because
 	 * resources can't be free, so reinitialization is impossible. */
-- 
2.32.0