Commit 742c60e1 authored by Nick Child's avatar Nick Child Committed by Jakub Kicinski
Browse files

ibmveth: Reduce default tx queues to 8 



Previously, the default number of transmit queues was 16. Due to
resource concerns, set to 8 queues instead. Still allow the user
to set more queues (max 16) if they like.

Since the driver is virtualized away from the physical NIC, the purpose
of multiple queues is purely to allow for parallel calls to the
hypervisor. Therefore, there is no noticeable effect on performance by
reducing queue count to 8.

Fixes: d926793c ("ibmveth: Implement multi queue on xmit")
Reported-by: default avatarDave Taht <dave.taht@gmail.com>
Signed-off-by: default avatarNick Child <nnac123@linux.ibm.com>
Link: https://lore.kernel.org/r/20221107203215.58206-1-nnac123@linux.ibm.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent b0633491

drivers/net/ethernet/ibm/ibmveth.c

+2 −1
Original line number Diff line number Diff line
@@ -1757,7 +1757,8 @@ static int ibmveth_probe(struct vio_dev *dev, const struct vio_device_id *id) 
			kobject_uevent(kobj, KOBJ_ADD);

	}



	rc = netif_set_real_num_tx_queues(netdev, ibmveth_real_max_tx_queues());

	rc = netif_set_real_num_tx_queues(netdev, min(num_online_cpus(),

						      IBMVETH_DEFAULT_QUEUES));

	if (rc) {

		netdev_dbg(netdev, "failed to set number of tx queues rc=%d\n",

			   rc);

drivers/net/ethernet/ibm/ibmveth.h

+1 −0
Original line number Diff line number Diff line
@@ -100,6 +100,7 @@ static inline long h_illan_attributes(unsigned long unit_address, 
#define IBMVETH_MAX_BUF_SIZE (1024 * 128)

#define IBMVETH_MAX_TX_BUF_SIZE (1024 * 64)

#define IBMVETH_MAX_QUEUES 16U

#define IBMVETH_DEFAULT_QUEUES 8U



static int pool_size[] = { 512, 1024 * 2, 1024 * 16, 1024 * 32, 1024 * 64 };

static int pool_count[] = { 256, 512, 256, 256, 256 };