Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

Pull RCU fix from Ingo Molnar:
 "An RCU Kconfig fix that eliminates an annoying interactive kconfig
  question for CONFIG_RCU_TORTURE_TEST_SLOW_INIT"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rcu: Control grace-period delays directly from value

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 233165da782f51deb88c6373116d9d28a4fec38b..8cf7304b2867f5a113807afb0bd5dc0a3bd3cfc0 100644 (file)
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -162,11 +162,14 @@ static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp);
 static int kthread_prio = CONFIG_RCU_KTHREAD_PRIO;
 module_param(kthread_prio, int, 0644);
 
-/* Delay in jiffies for grace-period initialization delays. */
-static int gp_init_delay = IS_ENABLED(CONFIG_RCU_TORTURE_TEST_SLOW_INIT)
-                               ? CONFIG_RCU_TORTURE_TEST_SLOW_INIT_DELAY
-                               : 0;
+/* Delay in jiffies for grace-period initialization delays, debug only. */
+#ifdef CONFIG_RCU_TORTURE_TEST_SLOW_INIT
+static int gp_init_delay = CONFIG_RCU_TORTURE_TEST_SLOW_INIT_DELAY;
 module_param(gp_init_delay, int, 0644);
+#else /* #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_INIT */
+static const int gp_init_delay;
+#endif /* #else #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_INIT */
+#define PER_RCU_NODE_PERIOD 10 /* Number of grace periods between delays. */
 
 /*
  * Track the rcutorture test sequence number and the update version
@@ -1843,9 +1846,8 @@ static int rcu_gp_init(struct rcu_state *rsp)
                raw_spin_unlock_irq(&rnp->lock);
                cond_resched_rcu_qs();
                ACCESS_ONCE(rsp->gp_activity) = jiffies;
-               if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_SLOW_INIT) &&
-                   gp_init_delay > 0 &&
-                   !(rsp->gpnum % (rcu_num_nodes * 10)))
+               if (gp_init_delay > 0 &&
+                   !(rsp->gpnum % (rcu_num_nodes * PER_RCU_NODE_PERIOD)))
                        schedule_timeout_uninterruptible(gp_init_delay);
        }
 

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 17670573dda82d92a515d4519211e8bbe65b5f63..ba2b0c87e65b196c7c1f016798e0b59ea8dba97c 100644 (file)
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1281,6 +1281,7 @@ config RCU_TORTURE_TEST_SLOW_INIT_DELAY
        int "How much to slow down RCU grace-period initialization"
        range 0 5
        default 3
+       depends on RCU_TORTURE_TEST_SLOW_INIT
        help
          This option specifies the number of jiffies to wait between
          each rcu_node structure initialization.