8 files changed, 21 insertions, 14 deletions

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 62154edf1489..6468a715a0e4 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -353,7 +353,7 @@ void __blk_mq_complete_request(struct request *rq)
                 rq->csd.func = __blk_mq_complete_request_remote;
                 rq->csd.info = rq;
                 rq->csd.flags = 0;
-                __smp_call_function_single(ctx->cpu, &rq->csd);
+                smp_call_function_single_async(ctx->cpu, &rq->csd);
         } else {
                 rq->q->softirq_done_fn(rq);
         }
diff --git a/block/blk-softirq.c b/block/blk-softirq.c
index 6345b7ebd0df..ebd6b6f1bdeb 100644
--- a/block/blk-softirq.c
+++ b/block/blk-softirq.c
@@ -70,7 +70,7 @@ static int raise_blk_irq(int cpu, struct request *rq)
                 data->info = rq;
                 data->flags = 0;
 
-                __smp_call_function_single(cpu, data);
+                smp_call_function_single_async(cpu, data);
                 return 0;
         }
 
diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c
index 04115947accc..cb6654bfad77 100644
--- a/drivers/cpuidle/coupled.c
+++ b/drivers/cpuidle/coupled.c
@@ -323,7 +323,7 @@ static void cpuidle_coupled_poke(int cpu)
         struct call_single_data *csd = &per_cpu(cpuidle_coupled_poke_cb, cpu);
 
         if (!cpumask_test_and_set_cpu(cpu, &cpuidle_coupled_poke_pending))
-                __smp_call_function_single(cpu, csd);
+                smp_call_function_single_async(cpu, csd);
 }
 
 /**
diff --git a/include/linux/smp.h b/include/linux/smp.h
index b410a1f23281..633f5edd7470 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -50,7 +50,7 @@ void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
                 smp_call_func_t func, void *info, bool wait,
                 gfp_t gfp_flags);
 
-int __smp_call_function_single(int cpu, struct call_single_data *csd);
+int smp_call_function_single_async(int cpu, struct call_single_data *csd);
 
 #ifdef CONFIG_SMP
 
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index eba3d84765f3..0cca04a53de0 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -432,7 +432,7 @@ void hrtick_start(struct rq *rq, u64 delay)
         if (rq == this_rq()) {
                 __hrtick_restart(rq);
         } else if (!rq->hrtick_csd_pending) {
-                __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd);
+                smp_call_function_single_async(cpu_of(rq), &rq->hrtick_csd);
                 rq->hrtick_csd_pending = 1;
         }
 }
diff --git a/kernel/smp.c b/kernel/smp.c
index b76763189752..06d574e42c72 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -238,15 +238,22 @@ int smp_call_function_single(int cpu, smp_call_func_t func, void *info,
 EXPORT_SYMBOL(smp_call_function_single);
 
 /**
- * __smp_call_function_single(): Run a function on a specific CPU
+ * smp_call_function_single_async(): Run an asynchronous function on a
+ *                               specific CPU.
  * @cpu: The CPU to run on.
  * @csd: Pre-allocated and setup data structure
  *
- * Like smp_call_function_single(), but allow caller to pass in a
- * pre-allocated data structure. Useful for embedding @data inside
- * other structures, for instance.
+ * Like smp_call_function_single(), but the call is asynchonous and
+ * can thus be done from contexts with disabled interrupts.
+ *
+ * The caller passes his own pre-allocated data structure
+ * (ie: embedded in an object) and is responsible for synchronizing it
+ * such that the IPIs performed on the @csd are strictly serialized.
+ *
+ * NOTE: Be careful, there is unfortunately no current debugging facility to
+ * validate the correctness of this serialization.
  */
-int __smp_call_function_single(int cpu, struct call_single_data *csd)
+int smp_call_function_single_async(int cpu, struct call_single_data *csd)
 {
         int err = 0;
 
@@ -256,7 +263,7 @@ int __smp_call_function_single(int cpu, struct call_single_data *csd)
 
         return err;
 }
-EXPORT_SYMBOL_GPL(__smp_call_function_single);
+EXPORT_SYMBOL_GPL(smp_call_function_single_async);
 
 /*
  * smp_call_function_any - Run a function on any of the given cpus
diff --git a/kernel/up.c b/kernel/up.c
index 4e199d4cef8e..1760bf3d1463 100644
--- a/kernel/up.c
+++ b/kernel/up.c
@@ -22,7 +22,7 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
 }
 EXPORT_SYMBOL(smp_call_function_single);
 
-int __smp_call_function_single(int cpu, struct call_single_data *csd)
+int smp_call_function_single_async(int cpu, struct call_single_data *csd)
 {
         unsigned long flags;
 
@@ -31,7 +31,7 @@ int __smp_call_function_single(int cpu, struct call_single_data *csd)
         local_irq_restore(flags);
         return 0;
 }
-EXPORT_SYMBOL(__smp_call_function_single);
+EXPORT_SYMBOL(smp_call_function_single_async);
 
 int on_each_cpu(smp_call_func_t func, void *info, int wait)
 {
diff --git a/net/core/dev.c b/net/core/dev.c
index d1298128bff4..ac7a2abb7f1a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4128,7 +4128,7 @@ static void net_rps_action_and_irq_enable(struct softnet_data *sd)
                         struct softnet_data *next = remsd->rps_ipi_next;
 
                         if (cpu_online(remsd->cpu))
-                                __smp_call_function_single(remsd->cpu,
+                                smp_call_function_single_async(remsd->cpu,
                                                            &remsd->csd);
                         remsd = next;
                 }