Document WITNESS_COUNT and WITNESS_NO_VNODE

Reviewed by: bcr, kib
Differential Revision: D1789
MFC after: 3 days
Sponsored by: EMC / Isilon Storage Division

1 files changed, 24 insertions, 0 deletions

diff --git a/share/man/man4/witness.4 b/share/man/man4/witness.4
index ffd9f8f..e887c1d 100644
--- a/share/man/man4/witness.4
+++ b/share/man/man4/witness.4
@@ -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
@@ -56,6 +58,28 @@ 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.
 By default, the flag is off, but if the