Commit cece1945 authored Aug 07, 2010 by Changli Gao Committed by David S. Miller Aug 07, 2010

net: disable preemption before call smp_processor_id()



Although netif_rx() isn't expected to be called in process context with
preemption enabled, it'd better handle this case. And this is why get_cpu()
is used in the non-RPS #ifdef branch. If tree RCU is selected,
rcu_read_lock() won't disable preemption, so preempt_disable() should be
called explictly.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent ba78e2dd

net/core/dev.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -2517,6 +2517,7 @@ int netif_rx(struct sk_buff *skb)
		struct rps_dev_flow voidflow, *rflow = &voidflow;
		int cpu;

		preempt_disable();
		rcu_read_lock();

		cpu = get_rps_cpu(skb->dev, skb, &rflow);
		@@ -2526,6 +2527,7 @@ int netif_rx(struct sk_buff *skb)
		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);

		rcu_read_unlock();
		preempt_enable();
		}
		#else
		{