From patchwork Mon Nov 24 18:33:52 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pankaj Gupta X-Patchwork-Id: 414104 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 99991140170 for ; Tue, 25 Nov 2014 07:25:52 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751076AbaKXUZE (ORCPT ); Mon, 24 Nov 2014 15:25:04 -0500 Received: from [114.143.55.155] ([114.143.55.155]:11088 "EHLO dhcp223-82.pnq.redhat.com" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751031AbaKXUZD (ORCPT ); Mon, 24 Nov 2014 15:25:03 -0500 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 sAOIXuDF010120; Tue, 25 Nov 2014 00:03:56 +0530 Received: (from root@localhost) by dhcp223-82.pnq.redhat.com (8.14.7/8.14.7/Submit) id sAOIXuwt010119; Tue, 25 Nov 2014 00:03:56 +0530 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 1/3] net: allow large number of rx queues Date: Tue, 25 Nov 2014 00:03:52 +0530 Message-Id: <1416854032-10083-1-git-send-email-pagupta@redhat.com> X-Mailer: git-send-email 1.8.3.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org netif_alloc_rx_queues() uses kcalloc() to allocate memory for "struct netdev_queue *_rx" array. If we are doing large rx queue allocation kcalloc() might fail, so this patch does a fallback to vzalloc(). Similar implementation is done for tx queue allocation in netif_alloc_netdev_queues(). We avoid failure of high order memory allocation with the help of vzalloc(), this allows us to do large rx and tx queue allocation which in turn helps us to increase the number of queues in tun. As vmalloc() adds overhead on a critical network path, __GFP_REPEAT flag is used with kzalloc() to do this fallback only when really needed. Signed-off-by: Pankaj Gupta Reviewed-by: Michael S. Tsirkin Reviewed-by: David Gibson --- net/core/dev.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index e916ba8..abe9560 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6059,17 +6059,25 @@ void netif_stacked_transfer_operstate(const struct net_device *rootdev, EXPORT_SYMBOL(netif_stacked_transfer_operstate); #ifdef CONFIG_SYSFS +static void netif_free_rx_queues(struct net_device *dev) +{ + kvfree(dev->_rx); +} + static int netif_alloc_rx_queues(struct net_device *dev) { unsigned int i, count = dev->num_rx_queues; struct netdev_rx_queue *rx; + size_t sz = count * sizeof(*rx); BUG_ON(count < 1); - rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL); - if (!rx) - return -ENOMEM; - + rx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT); + if (!rx) { + rx = vzalloc(sz); + if (!rx) + return -ENOMEM; + } dev->_rx = rx; for (i = 0; i < count; i++) @@ -6698,9 +6706,8 @@ void free_netdev(struct net_device *dev) netif_free_tx_queues(dev); #ifdef CONFIG_SYSFS - kfree(dev->_rx); + netif_free_rx_queues(dev); #endif - kfree(rcu_dereference_protected(dev->ingress_queue, 1)); /* Flush device addresses */