From patchwork Tue Nov 18 16:22:58 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pankaj Gupta X-Patchwork-Id: 412118 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id B10B2140142 for ; Wed, 19 Nov 2014 05:09:01 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754551AbaKRSIG (ORCPT ); Tue, 18 Nov 2014 13:08:06 -0500 Received: from [114.143.50.60] ([114.143.50.60]:18818 "EHLO dhcp223-82.pnq.redhat.com" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1754379AbaKRSIF (ORCPT ); Tue, 18 Nov 2014 13:08:05 -0500 X-Greylist: delayed 1746 seconds by postgrey-1.27 at vger.kernel.org; Tue, 18 Nov 2014 13:05:53 EST Received: from dhcp223-82.pnq.redhat.com (localhost [127.0.0.1]) by dhcp223-82.pnq.redhat.com (8.14.7/8.14.7) with ESMTP id sAIGQ1Cp020880; Tue, 18 Nov 2014 21:56:01 +0530 Received: (from root@localhost) by dhcp223-82.pnq.redhat.com (8.14.7/8.14.7/Submit) id sAIGPeN3020503; Tue, 18 Nov 2014 21:55:40 +0530 From: Pankaj Gupta To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org Cc: davem@davemloft.net, jasowang@redhat.com, mst@redhat.com, dgibson@redhat.com, vfalico@gmail.com, edumazet@google.com, vyasevic@redhat.com, hkchu@google.com, wuzhy@linux.vnet.ibm.com.pnq.redhat.com, xemul@parallels.com, therbert@google.com, bhutchings@solarflare.com, xii@google.com, stephen@networkplumber.org, jiri@resnulli.us, sergei.shtylyov@cogentembedded.com, Pankaj Gupta Subject: [PATCH net-next 4/4] tuntap: Increase the number of queues in tun. Date: Tue, 18 Nov 2014 21:52:58 +0530 Message-Id: <1416327778-17716-5-git-send-email-pagupta@redhat.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1416327778-17716-1-git-send-email-pagupta@redhat.com> References: <1416327778-17716-1-git-send-email-pagupta@redhat.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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 tuntap: Accepts tuntap max queue length as net sysctl parameter 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 a9b3eb4..2fb31b7 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -115,10 +115,11 @@ 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 MIN_TAP_QUEUES 1 #define MAX_TAP_FLOWS 4096