MFC r257854 (discussed with alc@)

  As of r257209, all architectures have defined
  VM_KMEM_SIZE_SCALE.  In other words, every architecture is now
  auto-sizing the kmem arena.  This revision changes kmeminit() so
  that the definition of VM_KMEM_SIZE_SCALE becomes mandatory and
  the definition of VM_KMEM_SIZE becomes optional.

  Replace or eliminate all existing definitions of VM_KMEM_SIZE.
  With auto-sizing enabled, VM_KMEM_SIZE effectively became an
  alternate spelling for VM_KMEM_SIZE_MIN on most architectures.
  Use VM_KMEM_SIZE_MIN for clarity.

1 files changed, 10 insertions, 8 deletions

diff --git a/sys/powerpc/include/vmparam.h b/sys/powerpc/include/vmparam.h
index e8e22cd..2d50f94 100644
--- a/sys/powerpc/include/vmparam.h
+++ b/sys/powerpc/include/vmparam.h
@@ -172,21 +172,23 @@ struct pmap_physseg {
 #define	SGROWSIZ	(128UL*1024)		/* amount to grow stack */
 #endif
 
-#ifndef VM_KMEM_SIZE
-#define	VM_KMEM_SIZE		(12 * 1024 * 1024)
+/*
+ * How many physical pages per kmem arena virtual page.
+ */
+#ifndef VM_KMEM_SIZE_SCALE
+#define	VM_KMEM_SIZE_SCALE	(3)
 #endif
 
 /*
- * How many physical pages per KVA page allocated.
- * min(max(VM_KMEM_SIZE, Physical memory/VM_KMEM_SIZE_SCALE), VM_KMEM_SIZE_MAX)
- * is the total KVA space allocated for kmem_map.
+ * Optional floor (in bytes) on the size of the kmem arena.
  */
-#ifndef VM_KMEM_SIZE_SCALE
-#define VM_KMEM_SIZE_SCALE	(3)
+#ifndef VM_KMEM_SIZE_MIN
+#define	VM_KMEM_SIZE_MIN	(12 * 1024 * 1024)
 #endif
 
 /*
- * Ceiling on the amount of kmem_map KVA space: 40% of the entire KVA space.
+ * Optional ceiling (in bytes) on the size of the kmem arena: 40% of the
+ * usable KVA space.
  */
 #ifndef VM_KMEM_SIZE_MAX
 #define VM_KMEM_SIZE_MAX	((VM_MAX_SAFE_KERNEL_ADDRESS - \