diff options
Diffstat (limited to 'kernel/rcupdate.c')
| -rw-r--r-- | kernel/rcupdate.c | 63 |
1 files changed, 60 insertions, 3 deletions
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index 29ca1c6da59..48ab70384a4 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -46,12 +46,15 @@ #include <linux/export.h> #include <linux/hardirq.h> #include <linux/delay.h> +#include <linux/module.h> #define CREATE_TRACE_POINTS #include <trace/events/rcu.h> #include "rcu.h" +module_param(rcu_expedited, int, 0); + #ifdef CONFIG_PREEMPT_RCU /* @@ -401,11 +404,65 @@ EXPORT_SYMBOL_GPL(rcuhead_debug_descr); #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ #if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU) || defined(CONFIG_RCU_TRACE) -void do_trace_rcu_torture_read(char *rcutorturename, struct rcu_head *rhp) +void do_trace_rcu_torture_read(char *rcutorturename, struct rcu_head *rhp, + unsigned long secs, + unsigned long c_old, unsigned long c) { - trace_rcu_torture_read(rcutorturename, rhp); + trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c); } EXPORT_SYMBOL_GPL(do_trace_rcu_torture_read); #else -#define do_trace_rcu_torture_read(rcutorturename, rhp) do { } while (0) +#define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \ + do { } while (0) +#endif + +#ifdef CONFIG_RCU_STALL_COMMON + +#ifdef CONFIG_PROVE_RCU +#define RCU_STALL_DELAY_DELTA (5 * HZ) +#else +#define RCU_STALL_DELAY_DELTA 0 #endif + +int rcu_cpu_stall_suppress __read_mostly; /* 1 = suppress stall warnings. */ +int rcu_cpu_stall_timeout __read_mostly = CONFIG_RCU_CPU_STALL_TIMEOUT; + +module_param(rcu_cpu_stall_suppress, int, 0644); +module_param(rcu_cpu_stall_timeout, int, 0644); + +int rcu_jiffies_till_stall_check(void) +{ + int till_stall_check = ACCESS_ONCE(rcu_cpu_stall_timeout); + + /* + * Limit check must be consistent with the Kconfig limits + * for CONFIG_RCU_CPU_STALL_TIMEOUT. + */ + if (till_stall_check < 3) { + ACCESS_ONCE(rcu_cpu_stall_timeout) = 3; + till_stall_check = 3; + } else if (till_stall_check > 300) { + ACCESS_ONCE(rcu_cpu_stall_timeout) = 300; + till_stall_check = 300; + } + return till_stall_check * HZ + RCU_STALL_DELAY_DELTA; +} + +static int rcu_panic(struct notifier_block *this, unsigned long ev, void *ptr) +{ + rcu_cpu_stall_suppress = 1; + return NOTIFY_DONE; +} + +static struct notifier_block rcu_panic_block = { + .notifier_call = rcu_panic, +}; + +static int __init check_cpu_stall_init(void) +{ + atomic_notifier_chain_register(&panic_notifier_list, &rcu_panic_block); + return 0; +} +early_initcall(check_cpu_stall_init); + +#endif /* #ifdef CONFIG_RCU_STALL_COMMON */ |