From: Pankaj Gupta Date: Mon, 12 Jan 2015 06:11:29 +0000 (+0530) Subject: tuntap: Increase the number of queues in tun. X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=baf71c5c1f80d82e92924050a60b5baaf97e3094;p=deliverable%2Flinux.git tuntap: Increase the number of queues in tun. Networking under kvm works best if we allocate a per-vCPU RX and TX queue in a virtual NIC. This requires a per-vCPU queue on the host side. It is now safe to increase the maximum number of queues. Preceding patch: 'net: allow large number of rx queues' made sure this won't cause failures due to high order memory allocations. Increase it to 256: this is the max number of vCPUs KVM supports. Size of tun_struct changes from 8512 to 10496 after this patch. This keeps pages allocated for tun_struct before and after the patch to 3. Signed-off-by: Pankaj Gupta Reviewed-by: David Gibson Signed-off-by: David S. Miller --- diff --git a/drivers/net/tun.c b/drivers/net/tun.c index c0df872f5b8c..74fdf1158448 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -124,10 +124,9 @@ struct tap_filter { unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN]; }; -/* DEFAULT_MAX_NUM_RSS_QUEUES were chosen to let the rx/tx queues allocated for - * the netdevice to be fit in one page. So we can make sure the success of - * memory allocation. TODO: increase the limit. */ -#define MAX_TAP_QUEUES DEFAULT_MAX_NUM_RSS_QUEUES +/* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal + * to max number of VCPUs in guest. */ +#define MAX_TAP_QUEUES 256 #define MAX_TAP_FLOWS 4096 #define TUN_FLOW_EXPIRE (3 * HZ)