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_RCU_BOOST -- one of PREEMPT_RCU. 18CONFIG_RCU_KTHREAD_PRIO -- set to 2 for _BOOST testing. 19CONFIG_RCU_FANOUT -- Cover hierarchy, but overlap with others. 20CONFIG_RCU_FANOUT_LEAF -- Do one non-default. 21CONFIG_RCU_FAST_NO_HZ -- Do one, but not with CONFIG_RCU_NOCB_CPU_ALL. 22CONFIG_RCU_NOCB_CPU -- Do three, see below. 23CONFIG_RCU_NOCB_CPU_ALL -- Do one. 24CONFIG_RCU_NOCB_CPU_NONE -- Do one. 25CONFIG_RCU_NOCB_CPU_ZERO -- Do one. 26CONFIG_RCU_TRACE -- Do half. 27CONFIG_SMP -- Need one !SMP for PREEMPT_RCU. 28!RCU_EXPERT -- Do a few, but these have to be vanilla configurations. 29RCU-bh: Do one with PREEMPT and one with !PREEMPT. 30RCU-sched: Do one with PREEMPT but not BOOST. 31 32 33Boot parameters: 34 35nohz_full - do at least one. 36maxcpu -- do at least one. 37rcupdate.rcu_self_test_bh -- Do at least one each, offloaded and not. 38rcupdate.rcu_self_test_sched -- Do at least one each, offloaded and not. 39rcupdate.rcu_self_test -- Do at least one each, offloaded and not. 40rcutree.rcu_fanout_exact -- Do at least one. 41 42 43Kconfig Parameters Ignored: 44 45CONFIG_64BIT 46 47 Used only to check CONFIG_RCU_FANOUT value, inspection suffices. 48 49CONFIG_NO_HZ_FULL_SYSIDLE_SMALL 50 51 Defer until Frederic uses this. 52 53CONFIG_PREEMPT_COUNT 54CONFIG_PREEMPT_RCU 55 56 Redundant with CONFIG_PREEMPT, ignore. 57 58CONFIG_RCU_BOOST_DELAY 59 60 Inspection suffices, ignore. 61 62CONFIG_RCU_CPU_STALL_TIMEOUT 63 64 Inspection suffices, ignore. 65 66CONFIG_RCU_STALL_COMMON 67 68 Implied by TREE_RCU and PREEMPT_RCU. 69 70CONFIG_RCU_TORTURE_TEST 71CONFIG_RCU_TORTURE_TEST_RUNNABLE 72 73 Always used in KVM testing. 74 75CONFIG_RCU_USER_QS 76 77 Redundant with CONFIG_NO_HZ_FULL. 78 79CONFIG_PREEMPT_RCU 80CONFIG_TREE_RCU 81 82 These are controlled by CONFIG_PREEMPT. 83