From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Jin Subject: [PATCH V3 2/2] xen-netfront: limit vnic max_queues number to online cpus Date: Fri, 23 Oct 2015 17:45:38 +0800 Message-ID: <562A01C2.20501@oracle.com> References: <562A0108.3070501@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, xen-devel@lists.xenproject.org To: wei.liu2@citrix.com, Ian Campbell , Boris Ostrovsky , Konrad Rzeszutek Wilk , "David S. Miller" , Jan Beulich Return-path: Received: from userp1040.oracle.com ([156.151.31.81]:19748 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750862AbbJWJpu (ORCPT ); Fri, 23 Oct 2015 05:45:50 -0400 In-Reply-To: <562A0108.3070501@oracle.com> Sender: netdev-owner@vger.kernel.org List-ID: Should not allocate vnic queues number more than online cpus. Signed-off-by: Joe Jin Cc: Jan Beulich Cc: Wei Liu Cc: Ian Campbell Cc: Boris Ostrovsky Cc: Konrad Rzeszutek Wilk --- drivers/net/xen-netfront.c | 28 ++++++++++++++++++++++------ 1 files changed, 22 insertions(+), 6 deletions(-) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index f821a97..5cc2f4a 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -58,7 +58,9 @@ /* Module parameters */ static unsigned int xennet_max_queues; -module_param_named(max_queues, xennet_max_queues, uint, 0644); +static int xennet_set_max_queues(const char *val, struct kernel_param *kp); +module_param_call(max_queues, xennet_set_max_queues, param_get_uint, + &xennet_max_queues, 0644); MODULE_PARM_DESC(max_queues, "Maximum number of queues per virtual interface"); @@ -164,6 +166,19 @@ struct netfront_rx_info { struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1]; }; +static int xennet_set_max_queues(const char *val, struct kernel_param *kp) +{ + unsigned int cpus = num_online_cpus(); + unsigned int max_queues = simple_strtoul(val, NULL, 10); + + if (max_queues == 0 || max_queues > cpus) { + pr_err("max_queues %u is out of range [1 - %u]!\n", + max_queues, cpus); + return -ERANGE; + } + return param_set_uint(val, kp); +} + static void skb_entry_set_link(union skb_entry *list, unsigned short id) { list->link = id; @@ -2126,6 +2141,8 @@ static struct xenbus_driver netfront_driver = { static int __init netif_init(void) { + unsigned int cpus = num_online_cpus(); + if (!xen_domain()) return -ENODEV; @@ -2134,11 +2151,10 @@ static int __init netif_init(void) pr_info("Initialising Xen virtual ethernet driver\n"); - /* Allow as many queues as there are CPUs if user has not - * specified a value. - */ - if (xennet_max_queues == 0) - xennet_max_queues = num_online_cpus(); + /* Allow at most as many queues as there are CPUs. */ + if (xennet_max_queues == 0 || xennet_max_queues > cpus) + xennet_max_queues = cpus; + pr_info("max_queues: %d\n", xennet_max_queues); return xenbus_register_frontend(&netfront_driver); } -- 1.7.1