[ Upstream commit c58543c8 ]

With lots of virtual devices it's easy to generate a lot of
events and chew up the kernel IRQ stack.
Reported-by: hyl <heyongli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>