common/fair_mutex: include <thread> only with CEPH_DEBUG_MUTEX

The header is only needed for std::this_thread::get_id() which is in
the `#ifdef CEPH_DEBUG_MUTEX` section.

Signed-off-by: Max Kellermann <max.kellermann@ionos.com>

diff --git a/src/common/fair_mutex.h b/src/common/fair_mutex.h
index 9baa0440048932e94eb058b7317b1eae9e53f1c8..3bf3b9b4aa29955f83efb55e78982dd40a6a9b44 100644 (file)
--- a/src/common/fair_mutex.h
+++ b/src/common/fair_mutex.h
@@ -4,7 +4,10 @@
 
 #include "common/ceph_mutex.h"
 
-#include <thread>
+#ifdef CEPH_DEBUG_MUTEX
+#include <thread> // for std::this_thread::get_id()
+#endif
+
 #include <string>
 
 namespace ceph {