Re: [PATCH] ixgbe: take online CPU number as MQ max limit when alloc_etherdev_mq()

From: Sergei Shtylyov
Date: Fri May 13 2016 - 08:52:51 EST


Hello.

On 5/13/2016 8:56 AM, Ethan Zhao wrote:

Allocating 64 Tx/Rx as default doesn't benefit perfomrnace when less

Performance.

CPUs were assigned. especially when DCB is enabled, so we should take
num_online_cpus() as top limit, and aslo to make sure every TC has

Also.

at least one queue, take the MAX_TRAFFIC_CLASS as bottom limit of queues
number.

Signed-off-by: Ethan Zhao <ethan.zhao@xxxxxxxxxx>
---
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 7df3fe2..1f9769c 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -9105,6 +9105,10 @@ static int ixgbe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
indices = IXGBE_MAX_RSS_INDICES;
#endif
}
+ /* Don't allocate too more queues than online cpus number */

"Too" not needed here. CPUs.

+ indices = min_t(int, indices, num_online_cpus());
+ /* To make sure TC works, allocate at least 1 queue per TC */
+ indices = max_t(int, indices, MAX_TRAFFIC_CLASS);

netdev = alloc_etherdev_mq(sizeof(struct ixgbe_adapter), indices);
if (!netdev) {

MBR, Sergei