diff options
| author | Paul E. McKenney <paulmck@linux.ibm.com> | 2019-06-13 15:30:49 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2019-08-01 14:05:51 -0700 |
| commit | cdc694b2359d52cd6d0465d5a6263d97c786fb0c (patch) | |
| tree | b23b91ce2d46cfbbb52f2bcd546cc1c471adb662 /kernel | |
| parent | 1f3ebc8253ee56bfaa883c5114fb5569c56f6197 (diff) | |
rcu: Add kernel parameter to dump trace after RCU CPU stall warning
This commit adds a rcu_cpu_stall_ftrace_dump kernel boot parameter, that,
when set, causes the trace buffer to be dumped after an RCU CPU stall
warning is printed. This kernel boot parameter is disabled by default,
maintaining compatibility with previous behavior.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/rcu.h | 1 | ||||
| -rw-r--r-- | kernel/rcu/tree_stall.h | 4 | ||||
| -rw-r--r-- | kernel/rcu/update.c | 2 |
3 files changed, 7 insertions, 0 deletions
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index 5290b01de534..8fd4f82c9b3d 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -227,6 +227,7 @@ static inline bool __rcu_reclaim(const char *rn, struct rcu_head *head) #ifdef CONFIG_RCU_STALL_COMMON +extern int rcu_cpu_stall_ftrace_dump; extern int rcu_cpu_stall_suppress; extern int rcu_cpu_stall_timeout; int rcu_jiffies_till_stall_check(void); diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h index 065183391f75..0627a66699a6 100644 --- a/kernel/rcu/tree_stall.h +++ b/kernel/rcu/tree_stall.h @@ -527,6 +527,8 @@ static void check_cpu_stall(struct rcu_data *rdp) /* We haven't checked in, so go dump stack. */ print_cpu_stall(); + if (rcu_cpu_stall_ftrace_dump) + rcu_ftrace_dump(DUMP_ALL); } else if (rcu_gp_in_progress() && ULONG_CMP_GE(j, js + RCU_STALL_RAT_DELAY) && @@ -534,6 +536,8 @@ static void check_cpu_stall(struct rcu_data *rdp) /* They had a few time units to dump stack, so complain. */ print_other_cpu_stall(gs2); + if (rcu_cpu_stall_ftrace_dump) + rcu_ftrace_dump(DUMP_ALL); } } diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 61df2bf08563..249517058b13 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -437,6 +437,8 @@ EXPORT_SYMBOL_GPL(rcutorture_sched_setaffinity); #endif #ifdef CONFIG_RCU_STALL_COMMON +int rcu_cpu_stall_ftrace_dump __read_mostly; +module_param(rcu_cpu_stall_ftrace_dump, int, 0644); int rcu_cpu_stall_suppress __read_mostly; /* 1 = suppress stall warnings. */ EXPORT_SYMBOL_GPL(rcu_cpu_stall_suppress); module_param(rcu_cpu_stall_suppress, int, 0644); |