path: root/drivers/net/xen-netback/netback.c
diff options
authorJuergen Gross <jgross@suse.com>2017-01-10 14:32:52 +0100
committerBoris Ostrovsky <boris.ostrovsky@oracle.com>2017-01-29 18:48:27 -0500
commit56dd5af9bc23d0d5d23bb207c477715b4c2216c5 (patch)
tree3d801b67474d3fe57d268c4eb8e573d8cb14a584 /drivers/net/xen-netback/netback.c
parentxen/netfront: set default upper limit of tx/rx queues to 8 (diff)
xen/netback: set default upper limit of tx/rx queues to 8
The default for the maximum number of tx/rx queues of one interface is the number of cpus of the system today. As each queue pair reserves 512 grant pages this default consumes a ridiculous number of grants for large guests. Limit the queue number to 8 as default. This value can be modified via a module parameter if required. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Diffstat (limited to 'drivers/net/xen-netback/netback.c')
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 47b481095d77..f9bcf4a665bc 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -67,6 +67,7 @@ module_param(rx_drain_timeout_msecs, uint, 0444);
unsigned int rx_stall_timeout_msecs = 60000;
module_param(rx_stall_timeout_msecs, uint, 0444);
unsigned int xenvif_max_queues;
module_param_named(max_queues, xenvif_max_queues, uint, 0644);
@@ -1622,11 +1623,12 @@ static int __init netback_init(void)
if (!xen_domain())
return -ENODEV;
- /* Allow as many queues as there are CPUs if user has not
+ /* Allow as many queues as there are CPUs but max. 8 if user has not
* specified a value.
if (xenvif_max_queues == 0)
- xenvif_max_queues = num_online_cpus();
+ xenvif_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
+ num_online_cpus());
if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",