Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750927AbaKXUYn (ORCPT ); Mon, 24 Nov 2014 15:24:43 -0500 Received: from [114.143.55.155] ([114.143.55.155]:11069 "EHLO dhcp223-82.pnq.redhat.com" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1750761AbaKXUYm (ORCPT ); Mon, 24 Nov 2014 15:24:42 -0500 From: Pankaj Gupta To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org Cc: davem@davemloft.net, jasowang@redhat.com, dgibson@redhat.com, vfalico@gmail.com, edumazet@google.com, vyasevic@redhat.com, hkchu@google.com, xemul@parallels.com, therbert@google.com, bhutchings@solarflare.com, xii@google.com, stephen@networkplumber.org, jiri@resnulli.us, sergei.shtylyov@cogentembedded.com, pagupta@redhat.com Subject: [PATCH v2 net-next 3/3] tuntap: Increase the number of queues in tun. Date: Tue, 25 Nov 2014 00:04:10 +0530 Message-Id: <1416854050-10165-1-git-send-email-pagupta@redhat.com> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 patches: net: allow large number of rx queues tuntap: Reduce the size of tun_struct by using flex array 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. Signed-off-by: Pankaj Gupta Reviewed-by: David Gibson --- drivers/net/tun.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index e3fa65a..a19dc5f8 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -113,10 +113,11 @@ 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. Also, we are making sure here + * queue memory allocation do not fail. + */ +#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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/