Index: sys/conf/NOTES
===================================================================
--- sys/conf/NOTES
+++ sys/conf/NOTES
@@ -2842,3 +2842,7 @@
 
 # Kernel support for stats(3).
 options 	STATS
+
+# Try to reduce memory usage. It may come as a tradeoff against performance
+# especially on multicore systems.
+#options 	COMPACT
Index: sys/conf/options
===================================================================
--- sys/conf/options
+++ sys/conf/options
@@ -1014,3 +1014,6 @@
 # gcov support
 GCOV		opt_global.h
 LINDEBUGFS
+
+# Try to reduce memory usage
+COMPACT		opt_global.h
Index: sys/sys/systm.h
===================================================================
--- sys/sys/systm.h
+++ sys/sys/systm.h
@@ -154,6 +154,14 @@
 } while (0)
 #endif /* INVARIANTS || _STANDALONE */
 
+#ifdef _KERNEL
+#ifndef	COMPACT
+#define	__aligned_if_not_compact(x)	__aligned(x)
+#else
+#define	__aligned_if_not_compact(x)
+#endif
+#endif
+
 /*
  * Helpful macros for quickly coming up with assertions with informative
  * panic messages.