Merge tag 'rtc-4.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni...

[mirror_ubuntu-artful-kernel.git] / lib / percpu_counter.c

diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c
index 9c21000df0b5ea1b99a83fd73a338073cb7fd016..3bf4a9984f4cb094b7d74550be1897c20ac292a6 100644 (file)
--- a/lib/percpu_counter.c
+++ b/lib/percpu_counter.c
@@ -72,7 +72,14 @@ void percpu_counter_set(struct percpu_counter *fbc, s64 amount)
 }
 EXPORT_SYMBOL(percpu_counter_set);
 
-void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch)
+/**
+ * This function is both preempt and irq safe. The former is due to explicit
+ * preemption disable. The latter is guaranteed by the fact that the slow path
+ * is explicitly protected by an irq-safe spinlock whereas the fast patch uses
+ * this_cpu_add which is irq-safe by definition. Hence there is no need muck
+ * with irq state before calling this one
+ */
+void percpu_counter_add_batch(struct percpu_counter *fbc, s64 amount, s32 batch)
 {
        s64 count;
 
@@ -89,7 +96,7 @@ void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch)
        }
        preempt_enable();
 }
-EXPORT_SYMBOL(__percpu_counter_add);
+EXPORT_SYMBOL(percpu_counter_add_batch);
 
 /*
  * Add up all the per-cpu counts, return the result.  This is a more accurate