From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Date: Sun, 30 Aug 2009 20:10:43 +0000 (+0000)
Subject: drop_monitor: fix trace_napi_poll_hit()
X-Git-Tag: v2.6.32-rc1~703^2~154
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=f2798eb4e01b095f273f4bf40f511c9d69c0e1da;p=karo-tx-linux.git

drop_monitor: fix trace_napi_poll_hit()

The net_dev of backlog napi is NULL, like below:

__get_cpu_var(softnet_data).backlog.dev == NULL

So, we should check it in napi tracepoint's probe function

Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c
index 9d66fa953ab7..d31120248c03 100644
--- a/net/core/drop_monitor.c
+++ b/net/core/drop_monitor.c
@@ -182,7 +182,8 @@ static void trace_napi_poll_hit(struct napi_struct *napi)
 	/*
 	 * Ratelimit our check time to dm_hw_check_delta jiffies
 	 */
-	if (!time_after(jiffies, napi->dev->last_rx + dm_hw_check_delta))
+	if (!napi->dev ||
+	    !time_after(jiffies, napi->dev->last_rx + dm_hw_check_delta))
 		return;
 
 	rcu_read_lock();