@@ -200,6 +217,16 @@ void percpu_write_lock_irqsave(struct percpu_rwlock *pcpu_rwlock,

        smp_mb(); /* Complete the wait-for-readers, before taking the lock */
        write_lock_irqsave(&pcpu_rwlock->global_rwlock, *flags);
+
+       /*
+        * It is desirable to allow the writer to acquire the percpu-rwlock
+        * for read (if necessary), without deadlocking or getting complaints
+        * from lockdep. To achieve that, just increment the reader_refcnt of
+        * this CPU - that way, any attempt by the writer to acquire the
+        * percpu-rwlock for read, will get treated as a case of nested percpu
+        * reader, which is safe, from a locking perspective.
+        */
+       this_cpu_inc(pcpu_rwlock->rw_state->reader_refcnt);