[PATCH tip/core/rcu 06/11] rcu: Inline RCU stall-warning info helper functions

From: Paul E. McKenney
Date: Tue Mar 26 2019 - 19:23:20 EST


The print_cpu_stall_info_begin() and print_cpu_stall_info_end() print a
single character each onto the console, and are a holdover from a time
when RCU CPU stall warning messages could be abbreviated using a long-gone
Kconfig option. This commit therefore adds these single characters to
already-printed strings in the calling functions, and then eliminates
both print_cpu_stall_info_begin() and print_cpu_stall_info_end().

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
---
kernel/rcu/tree.h | 2 --
kernel/rcu/tree_plugin.h | 12 ------------
kernel/rcu/tree_stall.h | 12 ++++--------
3 files changed, 4 insertions(+), 22 deletions(-)

diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index c6df9a13dd06..d73472af49e7 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -416,9 +416,7 @@ static void rcu_prepare_for_idle(void);
static bool rcu_preempt_has_tasks(struct rcu_node *rnp);
static bool rcu_preempt_need_deferred_qs(struct task_struct *t);
static void rcu_preempt_deferred_qs(struct task_struct *t);
-static void print_cpu_stall_info_begin(void);
static void print_cpu_stall_info(int cpu);
-static void print_cpu_stall_info_end(void);
static void zero_cpu_stall_ticks(struct rcu_data *rdp);
static bool rcu_nocb_cpu_needs_barrier(int cpu);
static struct swait_queue_head *rcu_nocb_gp_get(struct rcu_node *rnp);
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 72519c57f656..2df5bb04fd7a 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1550,12 +1550,6 @@ static void print_cpu_stall_fast_no_hz(char *cp, int cpu)

#endif /* #else #ifdef CONFIG_RCU_FAST_NO_HZ */

-/* Initiate the stall-info list. */
-static void print_cpu_stall_info_begin(void)
-{
- pr_cont("\n");
-}
-
/*
* Print out diagnostic information for the specified stalled CPU.
*
@@ -1606,12 +1600,6 @@ static void print_cpu_stall_info(int cpu)
fast_no_hz);
}

-/* Terminate the stall-info list. */
-static void print_cpu_stall_info_end(void)
-{
- pr_err("\t");
-}
-
/* Zero ->ticks_this_gp and snapshot the number of RCU softirq handlers. */
static void zero_cpu_stall_ticks(struct rcu_data *rdp)
{
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index b476786b8ef7..7ef3b596e45f 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -243,8 +243,7 @@ static void print_other_cpu_stall(unsigned long gp_seq)
* See Documentation/RCU/stallwarn.txt for info on how to debug
* RCU CPU stall warnings.
*/
- pr_err("INFO: %s detected stalls on CPUs/tasks:", rcu_state.name);
- print_cpu_stall_info_begin();
+ pr_err("INFO: %s detected stalls on CPUs/tasks:\n", rcu_state.name);
rcu_for_each_leaf_node(rnp) {
raw_spin_lock_irqsave_rcu_node(rnp, flags);
ndetected += rcu_print_task_stall(rnp);
@@ -258,10 +257,9 @@ static void print_other_cpu_stall(unsigned long gp_seq)
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}

- print_cpu_stall_info_end();
for_each_possible_cpu(cpu)
totqlen += rcu_get_n_cbs_cpu(cpu);
- pr_cont("(detected by %d, t=%ld jiffies, g=%ld, q=%lu)\n",
+ pr_cont("\t(detected by %d, t=%ld jiffies, g=%ld, q=%lu)\n",
smp_processor_id(), (long)(jiffies - rcu_state.gp_start),
(long)rcu_seq_current(&rcu_state.gp_seq), totqlen);
if (ndetected) {
@@ -314,15 +312,13 @@ static void print_cpu_stall(void)
* See Documentation/RCU/stallwarn.txt for info on how to debug
* RCU CPU stall warnings.
*/
- pr_err("INFO: %s self-detected stall on CPU", rcu_state.name);
- print_cpu_stall_info_begin();
+ pr_err("INFO: %s self-detected stall on CPU\n", rcu_state.name);
raw_spin_lock_irqsave_rcu_node(rdp->mynode, flags);
print_cpu_stall_info(smp_processor_id());
raw_spin_unlock_irqrestore_rcu_node(rdp->mynode, flags);
- print_cpu_stall_info_end();
for_each_possible_cpu(cpu)
totqlen += rcu_get_n_cbs_cpu(cpu);
- pr_cont(" (t=%lu jiffies g=%ld q=%lu)\n",
+ pr_cont("\t(t=%lu jiffies g=%ld q=%lu)\n",
jiffies - rcu_state.gp_start,
(long)rcu_seq_current(&rcu_state.gp_seq), totqlen);

--
2.17.1