bus: send memfds as payload only on directed messages and for large parts

1 files changed, 8 insertions, 1 deletions

diff --git a/src/libsystemd-bus/bus-kernel.h b/src/libsystemd-bus/bus-kernel.h
index ed3f987ccd..1651c1e41d 100644
--- a/src/libsystemd-bus/bus-kernel.h
+++ b/src/libsystemd-bus/bus-kernel.h
@@ -24,7 +24,14 @@
 #include "sd-bus.h"
 
 #define MEMFD_CACHE_MAX 32
-#define MEMFD_CACHE_ITEM_SIZE_MAX (128*1024)
+
+/* When we cache a memfd block for reuse, we will truncate blocks
+ * longer than this in order not to keep too much data around. */
+#define MEMFD_CACHE_ITEM_SIZE_MAX (32*1024)
+
+/* This determines at which minimum size we prefer sending memfds over
+ * sending vectors */
+#define MEMFD_MIN_SIZE (32*1024)
 
 struct memfd_cache {
         int fd;