netdev - question on pktgen shutdown logic.

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Date:	Wed, 22 May 2013 16:15:39 -0700
From:	Ben Greear <greearb@...delatech.com>
To:	netdev <netdev@...r.kernel.org>
Subject: question on pktgen shutdown logic.

While looking at pktgen.c in 3.9.3, I cannot explain how
it does not race on shutdown.

The thread worker checks for pktgen_exiting, and will bail out
of it's main loop and initiate cleanup if this is true.

The pg_net_exit sets the pktgen_exiting to true, and then
proceedes to call

		kthread_stop(t->tsk);
		kfree(t);

What I don't understand is what keeps the kfree(t) from happening
before the thread has noticed pktgen_exiting is set and properly
bailed out of it's loop and finished cleanup?

Thanks,
Ben

-- 
Ben Greear <greearb@...delatech.com>
Candela Technologies Inc  http://www.candelatech.com

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