rcu: print boot-time console messages if RCU configs out of ordinary

Print boot-time messages if tracing is enabled, if fanout is set
to non-default values, if exact fanout is specified, if accelerated
dyntick-idle grace periods have been enabled, if RCU-lockdep is enabled,
if rcutorture has been boot-time enabled, if the CPU stall detector has
been disabled, or if four-level hierarchy has been enabled.

This is all for TREE_RCU and TREE_PREEMPT_RCU.  TINY_RCU will be handled
separately, if at all.

Suggested-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney 2010-04-13 14:19:23 -07:00
parent c68de2097a
commit 26845c2860
2 changed files with 42 additions and 8 deletions

View file

@ -1938,12 +1938,6 @@ void __init rcu_init(void)
int cpu;
rcu_bootup_announce();
#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
printk(KERN_INFO "RCU-based detection of stalled CPUs is enabled.\n");
#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
#if NUM_RCU_LVL_4 != 0
printk(KERN_INFO "Experimental four-level hierarchy is enabled.\n");
#endif /* #if NUM_RCU_LVL_4 != 0 */
RCU_INIT_FLAVOR(&rcu_sched_state, rcu_sched_data);
RCU_INIT_FLAVOR(&rcu_bh_state, rcu_bh_data);
__rcu_init_preempt();

View file

@ -26,6 +26,45 @@
#include <linux/delay.h>
/*
* Check the RCU kernel configuration parameters and print informative
* messages about anything out of the ordinary. If you like #ifdef, you
* will love this function.
*/
static void __init rcu_bootup_announce_oddness(void)
{
#ifdef CONFIG_RCU_TRACE
printk(KERN_INFO "\tRCU debugfs-based tracing is enabled.\n");
#endif
#if (defined(CONFIG_64BIT) && CONFIG_RCU_FANOUT != 64) || (!defined(CONFIG_64BIT) && CONFIG_RCU_FANOUT != 32)
printk(KERN_INFO "\tCONFIG_RCU_FANOUT set to non-default value of %d\n",
CONFIG_RCU_FANOUT);
#endif
#ifdef CONFIG_RCU_FANOUT_EXACT
printk(KERN_INFO "\tHierarchical RCU autobalancing is disabled.\n");
#endif
#ifdef CONFIG_RCU_FAST_NO_HZ
printk(KERN_INFO
"\tRCU dyntick-idle grace-period acceleration is enabled.\n");
#endif
#ifdef CONFIG_PROVE_RCU
printk(KERN_INFO "\tRCU lockdep checking is enabled.\n");
#endif
#ifdef CONFIG_RCU_TORTURE_TEST_RUNNABLE
printk(KERN_INFO "\tRCU torture testing starts during boot.\n");
#endif
#ifndef CONFIG_RCU_CPU_STALL_DETECTOR
printk(KERN_INFO
"\tRCU-based detection of stalled CPUs is disabled.\n");
#endif
#ifndef CONFIG_RCU_CPU_STALL_VERBOSE
printk(KERN_INFO "\tVerbose stalled-CPUs detection is disabled.\n");
#endif
#if NUM_RCU_LVL_4 != 0
printk(KERN_INFO "\tExperimental four-level hierarchy is enabled.\n");
#endif
}
#ifdef CONFIG_TREE_PREEMPT_RCU
struct rcu_state rcu_preempt_state = RCU_STATE_INITIALIZER(rcu_preempt_state);
@ -38,8 +77,8 @@ static int rcu_preempted_readers_exp(struct rcu_node *rnp);
*/
static void __init rcu_bootup_announce(void)
{
printk(KERN_INFO
"Experimental preemptable hierarchical RCU implementation.\n");
printk(KERN_INFO "Preemptable hierarchical RCU implementation.\n");
rcu_bootup_announce_oddness();
}
/*
@ -757,6 +796,7 @@ void exit_rcu(void)
static void __init rcu_bootup_announce(void)
{
printk(KERN_INFO "Hierarchical RCU implementation.\n");
rcu_bootup_announce_oddness();
}
/*