rcu: Select IRQ_WORK from TREE_PREEMPT_RCU

TREE_RCU and TREE_PREEMPT_RCU both cause kernel/rcutree.c to be built,
but only TREE_RCU selects IRQ_WORK, which can result in an undefined
reference to irq_work_queue for some (random) configs:

kernel/built-in.o In function `rcu_start_gp_advanced':
kernel/rcutree.c:1564: undefined reference to `irq_work_queue'

Select IRQ_WORK from TREE_PREEMPT_RCU too to fix this.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

diff --git a/init/Kconfig b/init/Kconfig
index 247084b..c08a549 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -470,6 +470,7 @@ config TREE_RCU
 config TREE_PREEMPT_RCU
        bool "Preemptible tree-based hierarchical RCU"
        depends on PREEMPT
+       select IRQ_WORK
        help
          This option selects the RCU implementation that is
          designed for very large SMP systems with hundreds or