1 # SPDX-License-Identifier: GPL-2.0-only
3 # RCU-related debugging configuration options
12 bool "RCU list lockdep debugging"
13 depends on PROVE_RCU && RCU_EXPERT
16 Enable RCU lockdep checking for list usages. By default it is
17 turned off since there are several list RCU users that still
18 need to be converted to pass a lockdep expression. To prevent
19 false-positive splats, we keep it default disabled but once all
20 users are converted, we can remove this config option.
27 tristate "performance tests for RCU"
28 depends on DEBUG_KERNEL
33 select TASKS_TRACE_RCU
36 This option provides a kernel module that runs performance
37 tests on the RCU infrastructure. The kernel module may be built
38 after the fact on the running kernel to be tested, if desired.
40 Say Y here if you want RCU performance tests to be built into
42 Say M if you want the RCU performance tests to build as a module.
43 Say N if you are unsure.
45 config RCU_TORTURE_TEST
46 tristate "torture tests for RCU"
47 depends on DEBUG_KERNEL
53 This option provides a kernel module that runs torture tests
54 on the RCU infrastructure. The kernel module may be built
55 after the fact on the running kernel to be tested, if desired.
57 Say Y here if you want RCU torture tests to be built into
59 Say M if you want the RCU torture tests to build as a module.
60 Say N if you are unsure.
62 config RCU_REF_SCALE_TEST
63 tristate "Scalability tests for read-side synchronization (RCU and others)"
64 depends on DEBUG_KERNEL
69 select TASKS_TRACE_RCU
72 This option provides a kernel module that runs performance tests
73 useful comparing RCU with various read-side synchronization mechanisms.
74 The kernel module may be built after the fact on the running kernel to be
77 Say Y here if you want these performance tests built into the kernel.
78 Say M if you want to build it as a module instead.
79 Say N if you are unsure.
81 config RCU_CPU_STALL_TIMEOUT
82 int "RCU CPU stall timeout in seconds"
83 depends on RCU_STALL_COMMON
87 If a given RCU grace period extends more than the specified
88 number of seconds, a CPU stall warning is printed. If the
89 RCU grace period persists, additional CPU stall warnings are
90 printed at more widely spaced intervals.
93 bool "Enable tracing for RCU"
94 depends on DEBUG_KERNEL
98 This option enables additional tracepoints for ftrace-style
101 Say Y here if you want to enable RCU tracing
102 Say N if you are unsure.
105 bool "Provide debugging asserts for adding NO_HZ support to an arch"
106 depends on DEBUG_KERNEL
108 This option provides consistency checks in RCU's handling of
109 NO_HZ. These checks have proven quite helpful in detecting
110 bugs in arch-specific NO_HZ code.
112 Say N here if you need ultimate kernel/user switch latencies
113 Say Y if you are unsure
115 config RCU_STRICT_GRACE_PERIOD
116 bool "Provide debug RCU implementation with short grace periods"
117 depends on DEBUG_KERNEL && RCU_EXPERT && NR_CPUS <= 4
119 select PREEMPT_COUNT if PREEMPT=n
121 Select this option to build an RCU variant that is strict about
122 grace periods, making them as short as it can. This limits
123 scalability, destroys real-time response, degrades battery
124 lifetime and kills performance. Don't try this on large
125 machines, as in systems with more than about 10 or 20 CPUs.
126 But in conjunction with tools like KASAN, it can be helpful
127 when looking for certain types of RCU usage bugs, for example,
128 too-short RCU read-side critical sections.
130 endmenu # "RCU Debugging"