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_FAST_NO_HZ -- Do one, but not with all nohz_full CPUs. 19CONFIG_RCU_NOCB_CPU -- Do three, one with no rcu_nocbs CPUs, one with 20 rcu_nocbs=0, and one with all rcu_nocbs CPUs. 21CONFIG_RCU_TRACE -- Do half. 22CONFIG_SMP -- Need one !SMP for PREEMPT_RCU. 23CONFIG_RCU_EXPERT=n -- Do a few, but these have to be vanilla configurations. 24CONFIG_RCU_EQS_DEBUG -- Do at least one for CONFIG_NO_HZ_FULL and not. 25 26RCU-bh: Do one with PREEMPT and one with !PREEMPT. 27RCU-sched: Do one with PREEMPT but not BOOST. 28 29 30Boot parameters: 31 32nohz_full - do at least one. 33maxcpu -- do at least one. 34rcupdate.rcu_self_test_bh -- Do at least one each, offloaded and not. 35rcupdate.rcu_self_test_sched -- Do at least one each, offloaded and not. 36rcupdate.rcu_self_test -- Do at least one each, offloaded and not. 37rcutree.rcu_fanout_exact -- Do at least one. 38 39 40Kconfig Parameters Ignored: 41 42CONFIG_64BIT 43 44 Used only to check CONFIG_RCU_FANOUT value, inspection suffices. 45 46CONFIG_PREEMPT_COUNT 47CONFIG_PREEMPT_RCU 48 49 Redundant with CONFIG_PREEMPT, ignore. 50 51CONFIG_RCU_BOOST_DELAY 52 53 Inspection suffices, ignore. 54 55CONFIG_RCU_CPU_STALL_TIMEOUT 56 57 Inspection suffices, ignore. 58 59CONFIG_RCU_STALL_COMMON 60 61 Implied by TREE_RCU and PREEMPT_RCU. 62 63CONFIG_RCU_TORTURE_TEST 64CONFIG_RCU_TORTURE_TEST_RUNNABLE 65 66 Always used in KVM testing. 67 68CONFIG_PREEMPT_RCU 69CONFIG_TREE_RCU 70CONFIG_TINY_RCU 71CONFIG_TASKS_RCU 72 73 These are controlled by CONFIG_PREEMPT and/or CONFIG_SMP. 74 75CONFIG_SRCU 76 77 Selected by CONFIG_RCU_TORTURE_TEST, so cannot disable. 78 79 80boot parameters ignored: TBD 81