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-rw-r--r--Documentation/RCU/torture.txt21
-rw-r--r--kernel/rcutorture.c9
-rw-r--r--kernel/sysctl.c13
-rw-r--r--lib/Kconfig.debug21
4 files changed, 54 insertions, 10 deletions
diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt
index 02b3d14c0209..516527d4bc55 100644
--- a/Documentation/RCU/torture.txt
+++ b/Documentation/RCU/torture.txt
@@ -10,13 +10,20 @@ status messages via printk(), which can be examined via the dmesg
10command (perhaps grepping for "torture"). The test is started 10command (perhaps grepping for "torture"). The test is started
11when the module is loaded, and stops when the module is unloaded. 11when the module is loaded, and stops when the module is unloaded.
12 12
13However, actually setting this config option to "y" results in the system 13CONFIG_RCU_TORTURE_TEST_RUNNABLE
14running the test immediately upon boot, and ending only when the system 14
15is taken down. Normally, one will instead want to build the system 15It is also possible to specify CONFIG_RCU_TORTURE_TEST=y, which will
16with CONFIG_RCU_TORTURE_TEST=m and to use modprobe and rmmod to control 16result in the tests being loaded into the base kernel. In this case,
17the test, perhaps using a script similar to the one shown at the end of 17the CONFIG_RCU_TORTURE_TEST_RUNNABLE config option is used to specify
18this document. Note that you will need CONFIG_MODULE_UNLOAD in order 18whether the RCU torture tests are to be started immediately during
19to be able to end the test. 19boot or whether the /proc/sys/kernel/rcutorture_runnable file is used
20to enable them. This /proc file can be used to repeatedly pause and
21restart the tests, regardless of the initial state specified by the
22CONFIG_RCU_TORTURE_TEST_RUNNABLE config option.
23
24You will normally -not- want to start the RCU torture tests during boot
25(and thus the default is CONFIG_RCU_TORTURE_TEST_RUNNABLE=n), but doing
26this can sometimes be useful in finding boot-time bugs.
20 27
21 28
22MODULE PARAMETERS 29MODULE PARAMETERS
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 98ae7d168225..27003e2421c7 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -125,6 +125,13 @@ static struct list_head rcu_torture_removed;
125 125
126static int stutter_pause_test = 0; 126static int stutter_pause_test = 0;
127 127
128#if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
129#define RCUTORTURE_RUNNABLE_INIT 1
130#else
131#define RCUTORTURE_RUNNABLE_INIT 0
132#endif
133int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT;
134
128/* 135/*
129 * Allocate an element from the rcu_tortures pool. 136 * Allocate an element from the rcu_tortures pool.
130 */ 137 */
@@ -188,7 +195,7 @@ rcu_random(struct rcu_random_state *rrsp)
188static void 195static void
189rcu_stutter_wait(void) 196rcu_stutter_wait(void)
190{ 197{
191 while (stutter_pause_test) 198 while (stutter_pause_test || !rcutorture_runnable)
192 schedule_timeout_interruptible(1); 199 schedule_timeout_interruptible(1);
193} 200}
194 201
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 29116652dca8..c6887cf135c8 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -82,6 +82,9 @@ extern int maps_protect;
82extern int sysctl_stat_interval; 82extern int sysctl_stat_interval;
83extern int latencytop_enabled; 83extern int latencytop_enabled;
84extern int sysctl_nr_open_min, sysctl_nr_open_max; 84extern int sysctl_nr_open_min, sysctl_nr_open_max;
85#ifdef CONFIG_RCU_TORTURE_TEST
86extern int rcutorture_runnable;
87#endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
85 88
86/* Constants used for minimum and maximum */ 89/* Constants used for minimum and maximum */
87#if defined(CONFIG_DETECT_SOFTLOCKUP) || defined(CONFIG_HIGHMEM) 90#if defined(CONFIG_DETECT_SOFTLOCKUP) || defined(CONFIG_HIGHMEM)
@@ -813,6 +816,16 @@ static struct ctl_table kern_table[] = {
813 .child = key_sysctls, 816 .child = key_sysctls,
814 }, 817 },
815#endif 818#endif
819#ifdef CONFIG_RCU_TORTURE_TEST
820 {
821 .ctl_name = CTL_UNNUMBERED,
822 .procname = "rcutorture_runnable",
823 .data = &rcutorture_runnable,
824 .maxlen = sizeof(int),
825 .mode = 0644,
826 .proc_handler = &proc_dointvec,
827 },
828#endif
816/* 829/*
817 * NOTE: do not add new entries to this table unless you have read 830 * NOTE: do not add new entries to this table unless you have read
818 * Documentation/sysctl/ctl_unnumbered.txt 831 * Documentation/sysctl/ctl_unnumbered.txt
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index f51ba2fa2662..c35a86a516a0 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -537,11 +537,28 @@ config RCU_TORTURE_TEST
537 on the RCU infrastructure. The kernel module may be built 537 on the RCU infrastructure. The kernel module may be built
538 after the fact on the running kernel to be tested, if desired. 538 after the fact on the running kernel to be tested, if desired.
539 539
540 Say Y here if you want RCU torture tests to start automatically 540 Say Y here if you want RCU torture tests to be built into
541 at boot time (you probably don't). 541 the kernel.
542 Say M if you want the RCU torture tests to build as a module. 542 Say M if you want the RCU torture tests to build as a module.
543 Say N if you are unsure. 543 Say N if you are unsure.
544 544
545config RCU_TORTURE_TEST_RUNNABLE
546 bool "torture tests for RCU runnable by default"
547 depends on RCU_TORTURE_TEST = y
548 default n
549 help
550 This option provides a way to build the RCU torture tests
551 directly into the kernel without them starting up at boot
552 time. You can use /proc/sys/kernel/rcutorture_runnable
553 to manually override this setting. This /proc file is
554 available only when the RCU torture tests have been built
555 into the kernel.
556
557 Say Y here if you want the RCU torture tests to start during
558 boot (you probably don't).
559 Say N here if you want the RCU torture tests to start only
560 after being manually enabled via /proc.
561
545config KPROBES_SANITY_TEST 562config KPROBES_SANITY_TEST
546 bool "Kprobes sanity tests" 563 bool "Kprobes sanity tests"
547 depends on DEBUG_KERNEL 564 depends on DEBUG_KERNEL