From 37745d281069682d901f00c0121949a7d224195f Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 22 Jan 2015 18:24:08 -0800 Subject: rcu: Provide diagnostic option to slow down grace-period initialization Grace-period initialization normally proceeds quite quickly, so that it is very difficult to reproduce races against grace-period initialization. This commit therefore allows grace-period initialization to be artificially slowed down, increasing race-reproduction probability. A pair of new Kconfig parameters are provided, CONFIG_RCU_TORTURE_TEST_SLOW_INIT to enable the slowdowns, and CONFIG_RCU_TORTURE_TEST_SLOW_INIT_DELAY to specify the number of jiffies of slowdown to apply. A boot-time parameter named rcutree.gp_init_delay allows boot-time delay to be specified. By default, no delay will be applied even if CONFIG_RCU_TORTURE_TEST_SLOW_INIT is set. Signed-off-by: Paul E. McKenney --- Documentation/kernel-parameters.txt | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index bfcb1a62a7b4..94de410ec341 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2968,6 +2968,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Set maximum number of finished RCU callbacks to process in one batch. + rcutree.gp_init_delay= [KNL] + Set the number of jiffies to delay each step of + RCU grace-period initialization. This only has + effect when CONFIG_RCU_TORTURE_TEST_SLOW_INIT is + set. + rcutree.rcu_fanout_leaf= [KNL] Increase the number of CPUs assigned to each leaf rcu_node structure. Useful for very large -- cgit v1.2.3