From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: [PATCH] Bring comments in loopback.c uptodate. Date: Thu, 27 Sep 2007 16:39:53 -0600 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: To: David Miller Return-path: Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:42134 "EHLO ebiederm.dsl.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756078AbXI0WkF (ORCPT ); Thu, 27 Sep 2007 18:40:05 -0400 Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org A hint as to why it is safe to use per cpu variables, and note that we actually can have multiple instances of the loopback device now. Signed-off-by: Eric W. Biederman --- drivers/net/loopback.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c index 2617320..cba5c76 100644 --- a/drivers/net/loopback.c +++ b/drivers/net/loopback.c @@ -154,6 +154,7 @@ static int loopback_xmit(struct sk_buff *skb, struct net_device *dev) #endif dev->last_rx = jiffies; + /* it's OK to use per_cpu_ptr() because BHs are off */ pcpu_lstats = netdev_priv(dev); lb_stats = per_cpu_ptr(pcpu_lstats, smp_processor_id()); lb_stats->bytes += skb->len; @@ -221,7 +222,8 @@ static void loopback_dev_free(struct net_device *dev) } /* - * The loopback device is special. There is only one instance. + * The loopback device is special. There is only one instance + * per network namespace. */ static void loopback_setup(struct net_device *dev) { -- 1.5.3.rc6.17.g1911