Improve the informations reported in case of busy buffers during the shutdown:

- Axe out the SHOW_BUSYBUFS option and uses a tunable for selectively
enable/disable it, which is defaulted for not printing anything (0
value) but can be changed for printing (1 value) and be verbose (2
value)
- Improves the informations outputed: right now, there is no track of
the actual struct buf object or vnode which are referenced by the
shutdown process, but it is printed the related struct bufobj object
which is not really helpful
- Add more verbosity about the state of the struct buf lock and the
vnode informations, with the latter to be activated separately by the
sysctl

Sponsored by:	Sandvine Incorporated
Reviewed by:	emaste, kib
Approved by:	re (ksmith)
MFC after:	10 days

2 files changed, 0 insertions, 2 deletions

diff --git a/sys/conf/NOTES b/sys/conf/NOTES
index 59f02c8..fd76593 100644
--- a/sys/conf/NOTES
+++ b/sys/conf/NOTES
@@ -2929,7 +2929,6 @@ options 	SCSI_NCR_MYADDR=7
 options 	SC_DEBUG_LEVEL=5	# Syscons debug level
 options 	SC_RENDER_DEBUG	# syscons rendering debugging
 
-options 	SHOW_BUSYBUFS	# List buffers that prevent root unmount
 options 	VFS_BIO_DEBUG	# VFS buffer I/O debugging
 
 options 	KSTACK_MAX_PAGES=32 # Maximum pages to give the kernel stack
diff --git a/sys/conf/options b/sys/conf/options
index b36a644..a7f12124 100644
--- a/sys/conf/options
+++ b/sys/conf/options
@@ -156,7 +156,6 @@ QUOTA
 SCHED_4BSD	opt_sched.h
 SCHED_STATS	opt_sched.h
 SCHED_ULE	opt_sched.h
-SHOW_BUSYBUFS
 SLEEPQUEUE_PROFILING
 SLHCI_DEBUG	opt_slhci.h
 SPX_HACK