1This document gives a brief rationale for the TREE_RCU-related test
2cases, a group that includes PREEMPT_RCU.
3
4
5Kconfig Parameters:
6
7CONFIG_DEBUG_LOCK_ALLOC -- Do three, covering CONFIG_PROVE_LOCKING & not.
8CONFIG_DEBUG_OBJECTS_RCU_HEAD -- Do one.
9CONFIG_HZ_PERIODIC -- Do one.
10CONFIG_NO_HZ_IDLE -- Do those not otherwise specified. (Groups of two.)
11CONFIG_NO_HZ_FULL -- Do two, one with partial CPU enablement.
12CONFIG_PREEMPT -- Do half.  (First three and #8.)
13CONFIG_PROVE_LOCKING -- Do several, covering CONFIG_DEBUG_LOCK_ALLOC=y and not.
14CONFIG_PROVE_RCU -- Hardwired to CONFIG_PROVE_LOCKING.
15CONFIG_RCU_BOOST -- one of PREEMPT_RCU.
16CONFIG_RCU_FANOUT -- Cover hierarchy, but overlap with others.
17CONFIG_RCU_FANOUT_LEAF -- Do one non-default.
18CONFIG_RCU_NOCB_CPU -- Do three, one with no rcu_nocbs CPUs, one with
19	rcu_nocbs=0, and one with all rcu_nocbs CPUs.
20CONFIG_RCU_TRACE -- Do half.
21CONFIG_SMP -- Need one !SMP for PREEMPT_RCU.
22CONFIG_RCU_EXPERT=n -- Do a few, but these have to be vanilla configurations.
23CONFIG_RCU_EQS_DEBUG -- Do at least one for CONFIG_NO_HZ_FULL and not.
24
25RCU-bh: Do one with PREEMPT and one with !PREEMPT.
26RCU-sched: Do one with PREEMPT but not BOOST.
27
28
29Boot parameters:
30
31nohz_full - do at least one.
32maxcpu -- do at least one.
33rcupdate.rcu_self_test_bh -- Do at least one each, offloaded and not.
34rcupdate.rcu_self_test_sched -- Do at least one each, offloaded and not.
35rcupdate.rcu_self_test -- Do at least one each, offloaded and not.
36rcutree.rcu_fanout_exact -- Do at least one.
37
38
39Kconfig Parameters Ignored:
40
41CONFIG_64BIT
42
43	Used only to check CONFIG_RCU_FANOUT value, inspection suffices.
44
45CONFIG_PREEMPT_COUNT
46CONFIG_PREEMPT_RCU
47
48	Redundant with CONFIG_PREEMPT, ignore.
49
50CONFIG_RCU_BOOST_DELAY
51
52	Inspection suffices, ignore.
53
54CONFIG_RCU_CPU_STALL_TIMEOUT
55
56	Inspection suffices, ignore.
57
58CONFIG_RCU_STALL_COMMON
59
60	Implied by TREE_RCU and PREEMPT_RCU.
61
62CONFIG_RCU_TORTURE_TEST
63CONFIG_RCU_TORTURE_TEST_RUNNABLE
64
65	Always used in KVM testing.
66
67CONFIG_PREEMPT_RCU
68CONFIG_TREE_RCU
69CONFIG_TINY_RCU
70CONFIG_TASKS_RCU
71
72	These are controlled by CONFIG_PREEMPT and/or CONFIG_SMP.
73
74
75boot parameters ignored: TBD
76