From 7fa270010e0ddd3693381431f373b3e3135b0695 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 20 Apr 2015 10:27:15 -0700 Subject: rcu: Convert CONFIG_RCU_FANOUT_EXACT to boot parameter The CONFIG_RCU_FANOUT_EXACT Kconfig parameter is used primarily (and perhaps only) by rcutorture to verify that RCU works correctly in specific rcu_node combining-tree configurations. It therefore does not make much sense have this as a question to people attempting to configure their kernels. So this commit creates an rcutree.rcu_fanout_exact= boot parameter that rcutorture can use, and eliminates the original CONFIG_RCU_FANOUT_EXACT Kconfig parameter. Reported-by: Ingo Molnar Signed-off-by: Paul E. McKenney Reviewed-by: Pranith Kumar --- Documentation/kernel-parameters.txt | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation/kernel-parameters.txt') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 10a4fb80c033..f5582dcdf80d 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3010,6 +3010,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. the rcu_node combining tree. This only has effect when CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT is set. + rcutree.rcu_fanout_exact= [KNL] + Disable autobalancing of the rcu_node combining + tree. This is used by rcutorture, and might + possibly be useful for architectures having high + cache-to-cache transfer latencies. + 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