svn commit: r326424 - head/sys/vm

[Konstantin Belousov]

Author: kib
Date: Fri Dec  1 10:53:08 2017
New Revision: 326424
URL: https://svnweb.freebsd.org/changeset/base/326424

Log:
  Add comment for vm_map_find_min().
  
  Reviewed by:	alc
  Sponsored by:	The FreeBSD Foundation
  MFC after:	3 days
  X-Differential revision:	https://reviews.freebsd.org/D13155

Modified:
  head/sys/vm/vm_map.c

Modified: head/sys/vm/vm_map.c
==============================================================================
--- head/sys/vm/vm_map.c	Fri Dec  1 10:25:52 2017	(r326423)
+++ head/sys/vm/vm_map.c	Fri Dec  1 10:53:08 2017	(r326424)
@@ -1558,6 +1558,18 @@ again:
 	return (result);
 }
 
+/*
+ *	vm_map_find_min() is a variant of vm_map_find() that takes an
+ *	additional parameter (min_addr) and treats the given address
+ *	(*addr) differently.  Specifically, it treats *addr as a hint
+ *	and not as the minimum address where the mapping is created.
+ *
+ *	This function works in two phases.  First, it tries to
+ *	allocate above the hint.  If that fails and the hint is
+ *	greater than min_addr, it performs a second pass, replacing
+ *	the hint with min_addr as the minimum address for the
+ *	allocation.
+ */
 int
 vm_map_find_min(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
     vm_offset_t *addr, vm_size_t length, vm_offset_t min_addr,