diff --git a/sys/conf/options.riscv b/sys/conf/options.riscv
--- a/sys/conf/options.riscv
+++ b/sys/conf/options.riscv
@@ -1,3 +1,3 @@
-
 RISCV				opt_global.h	# For cpu RISCV to work
 INTRNG				opt_global.h
+PV_STATS			opt_pmap.h
diff --git a/sys/riscv/conf/NOTES b/sys/riscv/conf/NOTES
--- a/sys/riscv/conf/NOTES
+++ b/sys/riscv/conf/NOTES
@@ -17,6 +17,9 @@
 options 	DDB_CTF			# Kernel ELF linker loads CTF data
 options 	RACCT_DEFAULT_TO_DISABLED # Set kern.racct.enable=0 by default
 
+# Enable detailed accounting by the PV entry allocator.
+options 	PV_STATS
+
 # RISC-V SBI console
 device		rcons
 
diff --git a/sys/riscv/riscv/pmap.c b/sys/riscv/riscv/pmap.c
--- a/sys/riscv/riscv/pmap.c
+++ b/sys/riscv/riscv/pmap.c
@@ -93,7 +93,6 @@
  * SUCH DAMAGE.
  */
 
-#include <sys/cdefs.h>
 /*
  *	Manages physical address maps.
  *
@@ -113,6 +112,8 @@
  *	and to when physical maps must be made correct.
  */
 
+#include "opt_pmap.h"
+
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/bitstring.h>
@@ -1910,7 +1911,6 @@
 	[_NPCM - 1] = PC_FREEL
 };
 
-#if 0
 #ifdef PV_STATS
 static int pc_chunk_count, pc_chunk_allocs, pc_chunk_frees, pc_chunk_tryfail;
 
@@ -1935,7 +1935,6 @@
 SYSCTL_INT(_vm_pmap, OID_AUTO, pv_entry_spare, CTLFLAG_RD, &pv_entry_spare, 0,
 	"Current number of spare pv entries");
 #endif
-#endif /* 0 */
 
 /*
  * We are in a serious low memory condition.  Resort to