Index: ceph/src/mds/PurgeQueue.cc
===================================================================
--- ceph.orig/src/mds/PurgeQueue.cc
+++ ceph/src/mds/PurgeQueue.cc
@@ -499,7 +499,7 @@ void PurgeQueue::_execute_item(
 
   in_flight[expire_to] = item;
   logger->set(l_pq_executing, in_flight.size());
-  files_high_water = std::max(files_high_water, in_flight.size());
+  files_high_water = std::max(files_high_water, static_cast<uint64_t>(in_flight.size()));
   logger->set(l_pq_executing_high_water, files_high_water);
   auto ops = _calculate_ops(item);
   ops_in_flight += ops;
@@ -577,7 +577,7 @@ void PurgeQueue::_execute_item(
     logger->set(l_pq_executing_ops_high_water, ops_high_water);
     in_flight.erase(expire_to);
     logger->set(l_pq_executing, in_flight.size());
-    files_high_water = std::max(files_high_water, in_flight.size());
+    files_high_water = std::max(files_high_water, static_cast<uint64_t>(in_flight.size()));
     logger->set(l_pq_executing_high_water, files_high_water);
     return;
   }
@@ -654,7 +654,7 @@ void PurgeQueue::_execute_item_complete(
 
   in_flight.erase(iter);
   logger->set(l_pq_executing, in_flight.size());
-  files_high_water = std::max(files_high_water, in_flight.size());
+  files_high_water = std::max(files_high_water, static_cast<uint64_t>(in_flight.size()));
   logger->set(l_pq_executing_high_water, files_high_water);
   dout(10) << "in_flight.size() now " << in_flight.size() << dendl;