Re: [RFC 2/4] tuntap: Publish tuntap maximum number of queues as module_param

Jiri Pirko
2014-08-20T10:58:22Z

Mon, Aug 18, 2014 at 03:37:18PM CEST, pagupta@redhat.com wrote:
> This patch publishes maximum number of tun/tap queues allocated as a
> read_only module parameter which a user space application like libvirt
> can make use of to limit maximum number of queues. Value of read_only
> module parameter can be writable only at module load time. If no value is set
> at module load time a default value 256 is used which is equal to maximum number
> of vCPUS allowed by KVM.
>
> Administrator can specify maximum number of queues only at the driver
> module load time.
>
>Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
>---
> drivers/net/tun.c | 13 +++++++++++--
> 1 files changed, 11 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/net/tun.c b/drivers/net/tun.c
>index acaaf67..1f518e2 100644
>--- a/drivers/net/tun.c
>+++ b/drivers/net/tun.c
>@@ -119,6 +119,9 @@ struct tap_filter {
>
> #define TUN_FLOW_EXPIRE (3 * HZ)
>
>+static int max_tap_queues = MAX_TAP_QUEUES;
>+module_param(max_tap_queues, int, S_IRUGO);

Please do not introduce new module paramaters. Please other ways to
interchange values with userspace.