diff --git a/src/runtime/proc.go b/src/runtime/proc.go
index 341d52a..739745a 100644
--- a/src/runtime/proc.go
+++ b/src/runtime/proc.go
@@ -3928,6 +3928,13 @@
 		return
 	}
 
+	// If mp.profilehz is 0, then profiling is not enabled for this thread.
+	// We must check this to avoid a deadlock between setcpuprofilerate
+	// and the call to cpuprof.add, below.
+	if mp != nil && mp.profilehz == 0 {
+		return
+	}
+
 	// On mips{,le}, 64bit atomics are emulated with spinlocks, in
 	// runtime/internal/atomic. If SIGPROF arrives while the program is inside
 	// the critical section, it creates a deadlock (when writing the sample).