netdev - [Question] Kernel preemption of BH handler

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Message-ID: <4F7034EB.8010707@ericsson.com>
Date:	Mon, 26 Mar 2012 11:20:43 +0200
From:	Erik Hugne <erik.hugne@...csson.com>
To:	"netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: [Question] Kernel preemption of BH handler

I have a BH handler that processes packets received from a netdevice.

my_bh_handler() {
   spin_lock_bh(my_lock);
   /*do stuff*/
   spin_unlock_bh(my_lock);
   /*do more stuff*/
}

First packet is received, and my_bh_handler() is currently processing it.
Now a new packet is received by the NIC and my_bh_handler() is preempted 
after my_lock have been released.

Is it possible that the second invocation of the BH routine is allowed 
to finish before the first?

//E
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