From: Arran Cudbard-Bell <a.cudbardb@freeradius.org>
Date: Wed, 14 Dec 2022 23:50:34 +0000 (-0600)
Subject: Shrink fr_dlist_head_t by packing the offset with num_elements
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b5c9a3cd25121;p=thirdparty%2Ffreeradius-server.git

Shrink fr_dlist_head_t by packing the offset with num_elements
---

diff --git a/src/lib/util/dlist.h b/src/lib/util/dlist.h
index 86cbb2f6475..bf4b5b89755 100644
--- a/src/lib/util/dlist.h
+++ b/src/lib/util/dlist.h
@@ -49,11 +49,17 @@ struct fr_dlist_s {
  * like at which offset the next/prev pointers can be found.
  */
 typedef struct {
-	size_t		offset;		//!< Positive offset from start of structure to #fr_dlist_t.
-	char const	*type;		//!< of items contained within the list.  Used for talloc
-					///< validation.
 	fr_dlist_t	entry;		//!< Struct holding the head and tail of the list.
+					///< First for efficient traversal.
+
+	unsigned int	offset;		//!< Positive offset from start of structure to #fr_dlist_t.
+					///< Yes, this should really be size_t, but we shave 8 bytes
+					///< off each head structure by making it unsigned int.
+
 	unsigned int	num_elements;	//!< Number of elements contained within the dlist.
+
+	char const	*type;		//!< of items contained within the list.  Used for talloc
+					///< validation.
 } fr_dlist_head_t;
 
 static_assert(sizeof(unsigned int) >= 4, "Unsigned integer too small on this platform");