From c69a00a12e26cf4faffdcdb340cb2d059b61d57e Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 25 Jan 2022 15:41:10 -0800 Subject: srcu: Add boot-time control over srcu_node array allocation This commit adds an srcu_tree.convert_to_big kernel parameter that either refuses to convert at all (0), converts immediately at init_srcu_struct() time (1), or lets rcutorture convert it (2). An addition contention-based dynamic conversion choice will be added, along with documentation. [ paulmck: Apply callback-scanning feedback from Neeraj Upadhyay. ] Co-developed-by: Neeraj Upadhyay Signed-off-by: Neeraj Upadhyay Signed-off-by: Paul E. McKenney --- Documentation/admin-guide/kernel-parameters.txt | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'Documentation/admin-guide') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 3f1cc5e317ed..1f1fcac7777d 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5608,6 +5608,19 @@ off: Disable mitigation and remove performance impact to RDRAND and RDSEED + srcutree.convert_to_big [KNL] + Specifies under what conditions an SRCU tree + srcu_struct structure will be converted to big + form, that is, with an rcu_node tree: + + 0: Never. + 1: At init_srcu_struct() time. + 2: When rcutorture decides to. + + Either way, the srcu_node tree will be sized based + on the actual runtime number of CPUs (nr_cpu_ids) + instead of the compile-time CONFIG_NR_CPUS. + srcutree.counter_wrap_check [KNL] Specifies how frequently to check for grace-period sequence counter wrap for the -- cgit v1.2.3