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

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Message-Id: <20190326232225.21332-6-paulmck@linux.ibm.com>
Date:   Tue, 26 Mar 2019 16:22:20 -0700
From:   "Paul E. McKenney" <paulmck@...ux.ibm.com>
To:     rcu@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, mingo@...nel.org,
        jiangshanlai@...il.com, dipankar@...ibm.com,
        akpm@...ux-foundation.org, mathieu.desnoyers@...icios.com,
        josh@...htriplett.org, tglx@...utronix.de, peterz@...radead.org,
        rostedt@...dmis.org, dhowells@...hat.com, edumazet@...gle.com,
        fweisbec@...il.com, oleg@...hat.com, joel@...lfernandes.org,
        "Paul E. McKenney" <paulmck@...ux.ibm.com>
Subject: [PATCH tip/core/rcu 06/11] rcu: Inline RCU stall-warning info helper functions

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@...ux.ibm.com>
---
 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