Be more aggressive in using superpages in all mappings of objects:

- Add a new address space allocation method (VMFS_OPTIMAL_SPACE) for
  vm_map_find() that will try to alter the alignment of a mapping to match
  any existing superpage mappings of the object being mapped.  If no
  suitable address range is found with the necessary alignment,
  vm_map_find() will fall back to using the simple first-fit strategy
  (VMFS_ANY_SPACE).
- Change mmap() without MAP_FIXED, shmat(), and the GEM mapping ioctl to
  use VMFS_OPTIMAL_SPACE instead of VMFS_ANY_SPACE.

Reviewed by:	alc (earlier version)
MFC after:	2 weeks

1 files changed, 2 insertions, 1 deletions

diff --git a/sys/vm/vm_mmap.c b/sys/vm/vm_mmap.c
index c7e22c3..a5e6792 100644
--- a/sys/vm/vm_mmap.c
+++ b/sys/vm/vm_mmap.c
@@ -1603,7 +1603,8 @@ vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
 	else if (fitit)
 		rv = vm_map_find(map, object, foff, addr, size,
 		    object != NULL && object->type == OBJT_DEVICE ?
-		    VMFS_ALIGNED_SPACE : VMFS_ANY_SPACE, prot, maxprot, docow);
+		    VMFS_ALIGNED_SPACE : VMFS_OPTIMAL_SPACE, prot, maxprot,
+		    docow);
 	else
 		rv = vm_map_fixed(map, object, foff, *addr, size,
 				 prot, maxprot, docow);