NetBSD-5.0.2/usr.sbin/lockstat/lockstat.8
.\" $NetBSD: lockstat.8,v 1.8 2008/04/30 13:11:02 martin Exp $
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.\" by Andrew Doran.
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.Dd July 14, 2007
.Dt LOCKSTAT 8
.Os
.Sh NAME
.Nm lockstat
.Nd display kernel locking statistics
.Sh SYNOPSIS
.Nm
.Op Fl ceflMmpst
.Op Fl b Ar nbuf
.Op Fl E Ar event
.Op Fl F Ar func
.Op Fl L Ar lock
.Op Fl N Ar nlist
.Op Fl o Ar file
.Op Fl T Ar type
.Ar command ...
.Sh DESCRIPTION
The
.Nm
command enables system wide tracing of kernel lock events, executes
the specified command, and when finished reports statistics to the user.
.Pp
Tracing may be ended early by sending
.Dv SIGINT
(Ctrl-C) to the process being executed by lockstat.
.Pp
The
.Nm lockstat
pseudo-device
driver must be present in the kernel, and the
.Nm
command may only be used by the root user.
.Pp
The options are as follows:
.Bl -tag -width wellhello
.It Fl b Ar nbuf
Adjust the number of trace buffers allocated by the kernel to
.Ar nbuf .
.It Fl c
Report percentage of total events by count, and sort the output by number
of events.
The default is to key on event timings.
.It Fl E Ar event
Limit tracing to one type of event.
Use the
.Fl e
option to list valid events.
.It Fl e
List valid event types for the
.Fl E
option and exit.
.It Fl F Ar func
Limit tracing to locking operations performed within the specified function.
.Ar func
must be the name of a valid function in the kernel.
.It Fl f
Trace only by calling functions; do not report on individual locks.
.It Fl L Ar lock
Limit tracing to one lock.
.Ar lock
may either be the name of a lock object in the kernel, or a kernel virtual
address.
.It Fl l
Trace only by lock; do not report on calling functions.
.It Fl M
Merge lock addresses within unique objects.
.It Fl m
Merge call sites within unique functions.
.It Fl N Ar nlist
Extract symbol information from the
.Ar nlist
file.
.It Fl o Ar file
Send output to the file named by
.Ar file ,
instead of the standard output (the default).
.It Fl p
Show the average number of events and time spent per CPU.
The default is to show the total values.
May be used in conjunction with the
.Fl s
option.
.It Fl s
Show the average number of events per second, and the average time spent per
second.
The default is to show the total values.
.It Fl T Ar type
Limit tracing to one type of lock.
Use the
.Fl t
option to list valid lock types.
.It Fl t
List valid lock types for the
.Fl T
option and exit.
.El
.Sh FILES
.Bl -tag -width /dev/lockstat -compact
.It Pa /dev/lockstat
.Nm
control device
.It Pa /dev/ksyms
default namelist
.It Pa /netbsd
namelist
.El
.Sh EXAMPLES
.Bd -literal
# lockstat -T kernel_lock sleep 10
Elapsed time: 10.01 seconds.
-- Kernel lock spin
Total% Count Time/ms Lock Caller
------ ------- --------- ---------------------- ------------------------------
100.00 74941 1545.54 kernel_lock \*[Lt]all\*[Gt]
43.54 28467 673.00 kernel_lock trap+71e
42.87 34466 662.51 kernel_lock syscall_plain+111
7.38 7565 114.14 kernel_lock uiomove+17a
1.92 1221 29.61 kernel_lock sleepq_block+20b
1.84 1759 28.40 kernel_lock trap+706
0.81 124 12.54 kernel_lock x86_softintlock+1a
0.64 587 9.87 kernel_lock pmap_load+2a6
0.52 214 8.10 kernel_lock intr_biglock_wrapper+1e
0.20 219 3.09 kernel_lock pmap_load+323
0.14 175 2.12 kernel_lock do_sys_wait+2d0
0.09 85 1.43 kernel_lock lwp_startup+66
0.04 49 0.64 kernel_lock sleepq_block+18c
0.01 10 0.12 kernel_lock lwp_userret+3c
.Ed
.Sh DIAGNOSTICS
.Bl -diag
.It "lockstat: incompatible lockstat interface version"
.Pp
The kernel device driver does not match the version of the
.Nm
command.
.It "lockstat: overflowed available kernel trace buffers"
.Pp
Increase the number of buffers using the
.Fl b
option.
.It "lockstat: ioctl: Invalid argument"
.Pp
The number of trace buffers is outside the minimum and maximum
bounds set by the kernel.
.El
.Sh SEE ALSO
.Xr ps 1 ,
.Xr systat 1 ,
.Xr vmstat 1 ,
.Xr iostat 8 ,
.Xr pstat 8
.Sh HISTORY
The
.Nm
command appeared in
.Nx 4.0 .