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| author | Juergen Gross <jgross@suse.com> | 2017-01-10 16:32:52 +0300 |
|---|---|---|
| committer | Boris Ostrovsky <boris.ostrovsky@oracle.com> | 2017-01-30 02:48:27 +0300 |
| commit | 56dd5af9bc23d0d5d23bb207c477715b4c2216c5 (patch) | |
| tree | 3d801b67474d3fe57d268c4eb8e573d8cb14a584 | |
| parent | 034702a64a6692a8d5d0d9630064a014fc633728 (diff) | |
| download | linux-56dd5af9bc23d0d5d23bb207c477715b4c2216c5.tar.xz | |
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>
| -rw-r--r-- | drivers/net/xen-netback/netback.c | 6 |
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); +#define MAX_QUEUES_DEFAULT 8 unsigned int xenvif_max_queues; module_param_named(max_queues, xenvif_max_queues, uint, 0644); MODULE_PARM_DESC(max_queues, @@ -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", |