From patchwork Mon Jan 12 06:11:28 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pankaj Gupta X-Patchwork-Id: 427557 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 ADA6614007D for ; Mon, 12 Jan 2015 17:12:28 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752198AbbALGMJ (ORCPT ); Mon, 12 Jan 2015 01:12:09 -0500 Received: from mx1.redhat.com ([209.132.183.28]:40399 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751792AbbALGMF (ORCPT ); Mon, 12 Jan 2015 01:12:05 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t0C6BpN5023117 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 12 Jan 2015 01:11:51 -0500 Received: from dhcp223-82.pnq.redhat.com ([10.65.223.16]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t0C6BXEt001262; Mon, 12 Jan 2015 01:11:45 -0500 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, 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 v5 net-next 1/2] net: allow large number of rx queues Date: Mon, 12 Jan 2015 11:41:28 +0530 Message-Id: <1421043089-30103-2-git-send-email-pagupta@redhat.com> In-Reply-To: <1421043089-30103-1-git-send-email-pagupta@redhat.com> References: <1421043089-30103-1-git-send-email-pagupta@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 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 | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 1ab168e..954591a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6145,13 +6145,16 @@ 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++) @@ -6781,7 +6784,7 @@ void free_netdev(struct net_device *dev) netif_free_tx_queues(dev); #ifdef CONFIG_SYSFS - kfree(dev->_rx); + kvfree(dev->_rx); #endif kfree(rcu_dereference_protected(dev->ingress_queue, 1));