rcu: Remove *_SLOW_* Kconfig options

The RCU_TORTURE_TEST_SLOW_PREINIT, RCU_TORTURE_TEST_SLOW_PREINIT_DELAY,
RCU_TORTURE_TEST_SLOW_PREINIT_DELAY, RCU_TORTURE_TEST_SLOW_INIT,
RCU_TORTURE_TEST_SLOW_INIT_DELAY, RCU_TORTURE_TEST_SLOW_CLEANUP,
and RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY Kconfig options are only
useful for torture testing, and there are the rcutree.gp_cleanup_delay,
rcutree.gp_init_delay, and rcutree.gp_preinit_delay kernel boot parameters
that rcutorture can use instead.  The effect of these parameters is to
artificially slow down grace period initialization and cleanup in order
to make some types of race conditions happen more often.

This commit therefore simplifies Tree RCU a bit by removing the Kconfig
options and adding the corresponding kernel parameters to rcutorture's
.boot files instead.  However, this commit also leaves out the kernel
parameters for TREE02, TREE04, and TREE07 in order to have about the
same number of tests slowed as not slowed.  TREE01, TREE03, TREE05,
and TREE06 are slowed, and the rest are not slowed.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

2 files changed, 9 insertions, 23 deletions

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index cac24f5..bbbddd8 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -177,26 +177,12 @@ module_param(kthread_prio, int, 0644);
 
 /* Delay in jiffies for grace-period initialization delays, debug only. */
 
-#ifdef CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT
-static int gp_preinit_delay = CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT_DELAY;
-module_param(gp_preinit_delay, int, 0644);
-#else /* #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT */
-static const int gp_preinit_delay;
-#endif /* #else #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT */
-
-#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 */
-
-#ifdef CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP
-static int gp_cleanup_delay = CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY;
-module_param(gp_cleanup_delay, int, 0644);
-#else /* #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP */
-static const int gp_cleanup_delay;
-#endif /* #else #ifdef CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP */
+static int gp_preinit_delay;
+module_param(gp_preinit_delay, int, 0444);
+static int gp_init_delay;
+module_param(gp_init_delay, int, 0444);
+static int gp_cleanup_delay;
+module_param(gp_cleanup_delay, int, 0444);
 
 /*
  * Number of grace periods between delays, normalized by the duration of
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 116cf83..0553d9f 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -109,11 +109,11 @@ static void __init rcu_bootup_announce_oddness(void)
 		pr_info("\tKick kthreads if too-long grace period.\n");
 	if (IS_ENABLED(CONFIG_DEBUG_OBJECTS_RCU_HEAD))
 		pr_info("\tRCU callback double-/use-after-free debug enabled.\n");
-	if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT))
+	if (gp_preinit_delay)
 		pr_info("\tRCU debug GP pre-init slowdown %d jiffies.\n", gp_preinit_delay);
-	if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_SLOW_INIT))
+	if (gp_init_delay)
 		pr_info("\tRCU debug GP init slowdown %d jiffies.\n", gp_init_delay);
-	if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP))
+	if (gp_cleanup_delay)
 		pr_info("\tRCU debug GP init slowdown %d jiffies.\n", gp_cleanup_delay);
 	if (IS_ENABLED(CONFIG_RCU_EQS_DEBUG))
 		pr_info("\tRCU debug extended QS entry/exit.\n");