From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Jin Subject: [PATCH V3 1/2] xen-netback: limit xen vif max queues number to online cpus Date: Fri, 23 Oct 2015 17:44:44 +0800 Message-ID: <562A018C.9060708@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 aserp1040.oracle.com ([141.146.126.69]:48448 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750895AbbJWJo4 (ORCPT ); Fri, 23 Oct 2015 05:44:56 -0400 In-Reply-To: <562A0108.3070501@oracle.com> Sender: netdev-owner@vger.kernel.org List-ID: Should not allocate xen vif 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-netback/netback.c | 28 ++++++++++++++++++++++------ 1 files changed, 22 insertions(+), 6 deletions(-) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index ec98d43..021dcb0 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -68,7 +68,9 @@ unsigned int rx_stall_timeout_msecs = 60000; module_param(rx_stall_timeout_msecs, uint, 0444); unsigned int xenvif_max_queues; -module_param_named(max_queues, xenvif_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, + &xenvif_max_queues, 0644); MODULE_PARM_DESC(max_queues, "Maximum number of queues per virtual interface"); @@ -107,6 +109,20 @@ static struct xen_netif_rx_response *make_rx_response(struct xenvif_queue *queue u16 size, u16 flags); +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_info("max_queues %u is out of range [1 - %u]!\n", + max_queues, cpus); + return -ERANGE; + } + + return param_set_uint(val, kp); +} + static inline unsigned long idx_to_pfn(struct xenvif_queue *queue, u16 idx) { @@ -2110,15 +2126,15 @@ int xenvif_dealloc_kthread(void *data) static int __init netback_init(void) { int rc = 0; + unsigned int cpus = num_online_cpus(); if (!xen_domain()) return -ENODEV; - /* Allow as many queues as there are CPUs if user has not - * specified a value. - */ - if (xenvif_max_queues == 0) - xenvif_max_queues = num_online_cpus(); + /* Allow at most as many queues as CPUs. */ + if (xenvif_max_queues == 0 || xenvif_max_queues > cpus) + xenvif_max_queues = cpus; + pr_info("vif max_queues: %u\n", xenvif_max_queues); if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) { pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n", -- 1.7.1