svn commit: r327356 - head/share/man/man4

[Ian Lepore]

Author: ian
Date: Fri Dec 29 20:00:19 2017
New Revision: 327356
URL: https://svnweb.freebsd.org/changeset/base/327356

Log:
  Correct a mistake and reword a couple sentences to clarify that "the value"
  refers to the scale value, not the kmem_arena size that results from scaling.
  
  Suggested by: alc@

Modified:
  head/share/man/man4/md.4

Modified: head/share/man/man4/md.4
==============================================================================
--- head/share/man/man4/md.4	Fri Dec 29 19:07:50 2017	(r327355)
+++ head/share/man/man4/md.4	Fri Dec 29 20:00:19 2017	(r327356)
@@ -116,19 +116,19 @@ The default value is 32, which is sufficient to map 12
 .It Cd options VM_KMEM_SIZE_SCALE=<num>
 This configures the amount of kernel virtual address (KVA) space to
 dedicate to the kmem_arena map.
-The value is the ratio of physical to virtual pages.
+The scale value is the ratio of physical to virtual pages.
 The default value of 3 allocates a page of KVA for each 3 pages
 of physical ram in the system.
 
 The kernel and modules, including the root image, also consume KVA.
 The combination of a large root image and the default scaling
-may preallocate so much KVA to kmem_arena that there is not enough
+may preallocate so much KVA that there is not enough
 remaining address space to allocate kernel stacks, IO buffers,
 and other resources that are not part of kmem_arena.
 Overallocating kmem_arena space is likely to manifest as failure to
 launch userland processes with "cannot allocate kernel stack" messages.
 
-Setting the value too high may result in kernel failure to allocate
+Setting the scale value too high may result in kernel failure to allocate
 memory because kmem_arena is too small, and the failure may require
 significant runtime to manifest.
 Empirically, a value of 5 works well for a 200 MiB root image on