svn commit: r277492 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs

[Will Andrews]

Author: will
Date: Wed Jan 21 17:03:11 2015
New Revision: 277492
URL: https://svnweb.freebsd.org/changeset/base/277492

Log:
  Add vfs.zfs.reference_tracking_enable sysctl/tunable.
  
  This is primarily for developer/debugging use; it enables built-in tagged
  tracking of refcounts inside ZFS.  It can only be enabled from the loader,
  since it modifies how in-core state is managed.  Default remains disabled.
  
  MFC after:	1 week
  Sponsored by:	Spectra Logic

Modified:
  head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/refcount.c

Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/refcount.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/refcount.c	Wed Jan 21 16:52:24 2015	(r277491)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/refcount.c	Wed Jan 21 17:03:11 2015	(r277492)
@@ -30,6 +30,10 @@
 
 #ifdef _KERNEL
 int reference_tracking_enable = FALSE; /* runs out of memory too easily */
+SYSCTL_DECL(_vfs_zfs);
+SYSCTL_INT(_vfs_zfs, OID_AUTO, reference_tracking_enable, CTLFLAG_RDTUN,
+    &reference_tracking_enable, 0,
+    "Track reference holders to refcount_t objects, used mostly by ZFS");
 #else
 int reference_tracking_enable = TRUE;
 #endif