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 <[email protected]> Reviewed-by: David Gibson <[email protected]> --- drivers/net/tun.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index e3fa65a..a3f13f7 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -113,10 +113,9 @@ 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) -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
