From 742c60e1285ca40642e988f7e3db92232171b27d Mon Sep 17 00:00:00 2001
From: Nick Child <nnac123@linux.ibm.com>
Date: Mon, 7 Nov 2022 14:32:15 -0600
Subject: [PATCH] ibmveth: Reduce default tx queues to 8
References: jsc#PED-2639
Patch-mainline: v6.1-rc5
Git-commit: 742c60e1285ca40642e988f7e3db92232171b27d
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: d926793c1de9 ("ibmveth: Implement multi queue on xmit")
Reported-by: Dave Taht <dave.taht@gmail.com>
Signed-off-by: Nick Child <nnac123@linux.ibm.com>
Link: https://lore.kernel.org/r/20221107203215.58206-1-nnac123@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
drivers/net/ethernet/ibm/ibmveth.c | 3 ++-
drivers/net/ethernet/ibm/ibmveth.h | 1 +
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index 3b14dc93f59d..5b96cd94dcd2 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -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);
diff --git a/drivers/net/ethernet/ibm/ibmveth.h b/drivers/net/ethernet/ibm/ibmveth.h
index daf6f615c03f..115d4c45aa77 100644
--- a/drivers/net/ethernet/ibm/ibmveth.h
+++ b/drivers/net/ethernet/ibm/ibmveth.h
@@ -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 };
--
2.35.3