kernel/rcu/Kconfig.debug

   1 # SPDX-License-Identifier: GPL-2.0-only
   2 #
   3 # RCU-related debugging configuration options
   4 #
   5
   6 menu "RCU Debugging"
   7
   8 config PROVE_RCU
   9         def_bool PROVE_LOCKING
  10
  11 config PROVE_RCU_LIST
  12         bool "RCU list lockdep debugging"
  13         depends on PROVE_RCU && RCU_EXPERT
  14         default n
  15         help
  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.
  21
  22 config TORTURE_TEST
  23         tristate
  24         default n
  25
  26 config RCU_SCALE_TEST
  27         tristate "performance tests for RCU"
  28         depends on DEBUG_KERNEL
  29         select TORTURE_TEST
  30         select SRCU
  31         select TASKS_RCU
  32         select TASKS_RUDE_RCU
  33         select TASKS_TRACE_RCU
  34         default n
  35         help
  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.
  39
  40           Say Y here if you want RCU performance tests to be built into
  41           the kernel.
  42           Say M if you want the RCU performance tests to build as a module.
  43           Say N if you are unsure.
  44
  45 config RCU_TORTURE_TEST
  46         tristate "torture tests for RCU"
  47         depends on DEBUG_KERNEL
  48         select TORTURE_TEST
  49         select SRCU
  50         select TASKS_RCU
  51         select TASKS_RUDE_RCU
  52         select TASKS_TRACE_RCU
  53         default n
  54         help
  55           This option provides a kernel module that runs torture tests
  56           on the RCU infrastructure.  The kernel module may be built
  57           after the fact on the running kernel to be tested, if desired.
  58
  59           Say Y here if you want RCU torture tests to be built into
  60           the kernel.
  61           Say M if you want the RCU torture tests to build as a module.
  62           Say N if you are unsure.
  63
  64 config RCU_REF_SCALE_TEST
  65         tristate "Scalability tests for read-side synchronization (RCU and others)"
  66         depends on DEBUG_KERNEL
  67         select TORTURE_TEST
  68         select SRCU
  69         select TASKS_RCU
  70         select TASKS_RUDE_RCU
  71         select TASKS_TRACE_RCU
  72         default n
  73         help
  74           This option provides a kernel module that runs performance tests
  75           useful comparing RCU with various read-side synchronization mechanisms.
  76           The kernel module may be built after the fact on the running kernel to be
  77           tested, if desired.
  78
  79           Say Y here if you want these performance tests built into the kernel.
  80           Say M if you want to build it as a module instead.
  81           Say N if you are unsure.
  82
  83 config RCU_CPU_STALL_TIMEOUT
  84         int "RCU CPU stall timeout in seconds"
  85         depends on RCU_STALL_COMMON
  86         range 3 300
  87         default 21
  88         help
  89           If a given RCU grace period extends more than the specified
  90           number of seconds, a CPU stall warning is printed.  If the
  91           RCU grace period persists, additional CPU stall warnings are
  92           printed at more widely spaced intervals.
  93
  94 config RCU_TRACE
  95         bool "Enable tracing for RCU"
  96         depends on DEBUG_KERNEL
  97         default y if TREE_RCU
  98         select TRACE_CLOCK
  99         help
 100           This option enables additional tracepoints for ftrace-style
 101           event tracing.
 102
 103           Say Y here if you want to enable RCU tracing
 104           Say N if you are unsure.
 105
 106 config RCU_EQS_DEBUG
 107         bool "Provide debugging asserts for adding NO_HZ support to an arch"
 108         depends on DEBUG_KERNEL
 109         help
 110           This option provides consistency checks in RCU's handling of
 111           NO_HZ.  These checks have proven quite helpful in detecting
 112           bugs in arch-specific NO_HZ code.
 113
 114           Say N here if you need ultimate kernel/user switch latencies
 115           Say Y if you are unsure
 116
 117 config RCU_STRICT_GRACE_PERIOD
 118         bool "Provide debug RCU implementation with short grace periods"
 119         depends on DEBUG_KERNEL && RCU_EXPERT
 120         default n
 121         select PREEMPT_COUNT if PREEMPT=n
 122         help
 123           Select this option to build an RCU variant that is strict about
 124           grace periods, making them as short as it can.  This limits
 125           scalability, destroys real-time response, degrades battery
 126           lifetime and kills performance.  Don't try this on large
 127           machines, as in systems with more than about 10 or 20 CPUs.
 128           But in conjunction with tools like KASAN, it can be helpful
 129           when looking for certain types of RCU usage bugs, for example,
 130           too-short RCU read-side critical sections.
 131
 132 endmenu # "RCU Debugging"