svn commit: r321279 - stable/10/share/man/man4

[Ngie Cooper]

Author: ngie
Date: Thu Jul 20 01:12:31 2017
New Revision: 321279
URL: https://svnweb.freebsd.org/changeset/base/321279

Log:
  MFC r278329:
  
  Document WITNESS_COUNT and WITNESS_NO_VNODE

Modified:
  stable/10/share/man/man4/witness.4
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/share/man/man4/witness.4
==============================================================================
--- stable/10/share/man/man4/witness.4	Thu Jul 20 01:11:58 2017	(r321278)
+++ stable/10/share/man/man4/witness.4	Thu Jul 20 01:12:31 2017	(r321279)
@@ -32,7 +32,9 @@
 .Nd lock validation facility
 .Sh SYNOPSIS
 .Cd options WITNESS
+.Cd options WITNESS_COUNT
 .Cd options WITNESS_KDB
+.Cd options WITNESS_NO_VNODE
 .Cd options WITNESS_SKIPSPIN
 .Sh DESCRIPTION
 The
@@ -55,6 +57,28 @@ code also checks various other conditions such as veri
 does not recurse on a non-recursive lock,
 or attempt an upgrade on a shared lock held by another thread.
 If any of these checks fail, then the kernel will panic.
+.Pp
+The
+.Dv WITNESS_COUNT
+kernel option controls the maximum number of
+.Xr witness 4
+entries that are tracked in the kernel.
+The maximum number of entries can be queried via the
+.Va debug.witness.count
+sysctl.
+It can also be set from the
+.Xr loader 8
+via the
+.Va debug.witness.count
+environment variable.
+.Pp
+The
+.Dv WITNESS_NO_VNODE
+kernel option tells
+.Xr witness 4
+to ignore locking issues between
+.Xr vnode 9
+objects.
 .Pp
 The flag that controls whether or not the kernel debugger is entered when a
 lock order violation is detected can be set in a variety of ways.