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_HOTPLUG_CPU -- Do half.  (Every second.)
10CONFIG_HZ_PERIODIC -- Do one.
11CONFIG_NO_HZ_IDLE -- Do those not otherwise specified. (Groups of two.)
12CONFIG_NO_HZ_FULL -- Do two, one with CONFIG_NO_HZ_FULL_SYSIDLE.
13CONFIG_NO_HZ_FULL_SYSIDLE -- Do one.
14CONFIG_PREEMPT -- Do half.  (First three and #8.)
15CONFIG_PROVE_LOCKING -- Do several, covering CONFIG_DEBUG_LOCK_ALLOC=y and not.
16CONFIG_PROVE_RCU -- Hardwired to CONFIG_PROVE_LOCKING.
17CONFIG_PROVE_RCU_REPEATEDLY -- Do one.
18CONFIG_RCU_BOOST -- one of PREEMPT_RCU.
19CONFIG_RCU_KTHREAD_PRIO -- set to 2 for _BOOST testing.
20CONFIG_RCU_FANOUT -- Cover hierarchy, but overlap with others.
21CONFIG_RCU_FANOUT_LEAF -- Do one non-default.
22CONFIG_RCU_FAST_NO_HZ -- Do one, but not with CONFIG_RCU_NOCB_CPU_ALL.
23CONFIG_RCU_NOCB_CPU -- Do three, see below.
24CONFIG_RCU_NOCB_CPU_ALL -- Do one.
25CONFIG_RCU_NOCB_CPU_NONE -- Do one.
26CONFIG_RCU_NOCB_CPU_ZERO -- Do one.
27CONFIG_RCU_TRACE -- Do half.
28CONFIG_SMP -- Need one !SMP for PREEMPT_RCU.
29CONFIG_RCU_EXPERT=n -- Do a few, but these have to be vanilla configurations.
30CONFIG_RCU_EQS_DEBUG -- Do at least one for CONFIG_NO_HZ_FULL and not.
31CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP -- Do for all but a couple TREE scenarios.
32CONFIG_RCU_TORTURE_TEST_SLOW_INIT -- Do for all but a couple TREE scenarios.
33CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT -- Do for all but a couple TREE scenarios.
34
35RCU-bh: Do one with PREEMPT and one with !PREEMPT.
36RCU-sched: Do one with PREEMPT but not BOOST.
37
38
39Boot parameters:
40
41nohz_full - do at least one.
42maxcpu -- do at least one.
43rcupdate.rcu_self_test_bh -- Do at least one each, offloaded and not.
44rcupdate.rcu_self_test_sched -- Do at least one each, offloaded and not.
45rcupdate.rcu_self_test -- Do at least one each, offloaded and not.
46rcutree.rcu_fanout_exact -- Do at least one.
47
48
49Kconfig Parameters Ignored:
50
51CONFIG_64BIT
52
53	Used only to check CONFIG_RCU_FANOUT value, inspection suffices.
54
55CONFIG_NO_HZ_FULL_SYSIDLE_SMALL
56
57	Defer until Frederic uses this.
58
59CONFIG_PREEMPT_COUNT
60CONFIG_PREEMPT_RCU
61
62	Redundant with CONFIG_PREEMPT, ignore.
63
64CONFIG_RCU_BOOST_DELAY
65
66	Inspection suffices, ignore.
67
68CONFIG_RCU_CPU_STALL_TIMEOUT
69
70	Inspection suffices, ignore.
71
72CONFIG_RCU_STALL_COMMON
73
74	Implied by TREE_RCU and PREEMPT_RCU.
75
76CONFIG_RCU_TORTURE_TEST
77CONFIG_RCU_TORTURE_TEST_RUNNABLE
78
79	Always used in KVM testing.
80
81CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT_DELAY
82CONFIG_RCU_TORTURE_TEST_SLOW_INIT_DELAY
83CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY
84
85	Inspection suffices, ignore.
86
87CONFIG_PREEMPT_RCU
88CONFIG_TREE_RCU
89CONFIG_TINY_RCU
90
91	These are controlled by CONFIG_PREEMPT and/or CONFIG_SMP.
92
93CONFIG_SPARSE_RCU_POINTER
94
95	Makes sense only for sparse runs, not for kernel builds.
96
97CONFIG_SRCU
98CONFIG_TASKS_RCU
99
100	Selected by CONFIG_RCU_TORTURE_TEST, so cannot disable.
101
102CONFIG_RCU_TRACE
103
104	Implied by CONFIG_RCU_TRACE for Tree RCU.
105
106
107boot parameters ignored: TBD
108