rcu: Remove "select IRQ_WORK" from config TREE_RCU

The 48a7639ce80c ("rcu: Make callers awaken grace-period kthread")
removed the irq_work_queue(), so the TREE_RCU doesn't need
irq work any more.  This commit therefore updates RCU's Kconfig and

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

2 files changed, 0 insertions, 3 deletions

diff --git a/init/Kconfig b/init/Kconfig
index 9afb971497f4..39b4313c6ca6 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -470,7 +470,6 @@ choice
 config TREE_RCU
         bool "Tree-based hierarchical RCU"
         depends on !PREEMPT && SMP
-        select IRQ_WORK
         help
           This option selects the RCU implementation that is
           designed for very large SMP system with hundreds or
@@ -480,7 +479,6 @@ config TREE_RCU
 config 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
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index cb5908672f11..41860b9a04a2 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -27,7 +27,6 @@
 #include <linux/threads.h>
 #include <linux/cpumask.h>
 #include <linux/seqlock.h>
-#include <linux/irq_work.h>
 
 /*
  * Define shape of hierarchy based on NR_CPUS, CONFIG_RCU_FANOUT, and