diff options
author | markj <markj@FreeBSD.org> | 2015-07-05 23:23:12 +0000 |
---|---|---|
committer | markj <markj@FreeBSD.org> | 2015-07-05 23:23:12 +0000 |
commit | 6386afc442f1b2e9c9a3ed99324c3acdc8141bfc (patch) | |
tree | 75bd90ec6e8788801302c78a3043ea4198c62c32 /share/man/man4/dtrace_io.4 | |
parent | 7cfe35b5a56da2c448ed7b95fb9d6a6ba7add51c (diff) | |
download | FreeBSD-src-6386afc442f1b2e9c9a3ed99324c3acdc8141bfc.zip FreeBSD-src-6386afc442f1b2e9c9a3ed99324c3acdc8141bfc.tar.gz |
Rename the dtrace-* man pages to dtrace_* for consistency with other
subsection man pages (e.g. geom_*, mac_*, snd_*).
Diffstat (limited to 'share/man/man4/dtrace_io.4')
-rw-r--r-- | share/man/man4/dtrace_io.4 | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/share/man/man4/dtrace_io.4 b/share/man/man4/dtrace_io.4 new file mode 100644 index 0000000..dea6221 --- /dev/null +++ b/share/man/man4/dtrace_io.4 @@ -0,0 +1,123 @@ +.\" Copyright (c) 2015 Mark Johnston <markj@FreeBSD.org> +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd April 18, 2015 +.Dt DTRACE_IO 4 +.Os +.Sh NAME +.Nm dtrace_io +.Nd a DTrace provider for tracing events related to disk I/O +.Sh SYNOPSIS +.Fn io:::start "struct bio *" "struct devstat *" +.Fn io:::done "struct bio *" "struct devstat *" +.Sh DESCRIPTION +The +.Nm io +provider allows the tracing of disk I/O events. +The +.Fn io:::start +probe fires when a I/O request is about to be sent to the backing driver of a +.Xr disk 9 +object. +This occurs after all +.Xr GEOM 4 +transformations have been performed on the request. +The +.Fn io:::done +probe fires when a I/O request is completed. +Both probes take a +.Vt "struct bio *" +representing the I/O request as their first argument. +The second argument is a +.Vt "struct devstat *" +for the underlying +.Xr disk 9 +object. +.Sh ARGUMENTS +The fields of +.Vt "struct bio" +are described in the +.Xr g_bio 9 +manual page, and the fields of +.Vt "struct devstat" +are described in the +.Xr devstat 9 +manual page. +Translators for the +.Vt bufinfo_t +and +.Vt devinfo_t +D types are defined in +.Pa /usr/lib/dtrace/io.d . +.Sh FILES +.Bl -tag -width "/usr/lib/dtrace/io.d" -compact +.It Pa /usr/lib/dtrace/io.d +DTrace type and translator definitions for the +.Nm io +provider. +.El +.Sh EXAMPLES +The following script shows a per-process breakdown of total I/O by disk device: +.Bd -literal -offset indent +#pragma D option quiet + +io:::start +{ + @[args[1]->device_name, execname, pid] = sum(args[0]->bio_bcount); +} + +END +{ + printf("%10s %20s %10s %15s\n", "DEVICE", "APP", "PID", "BYTES"); + printa("%10s %20s %10d %15@d\n", @); +} +.Ed +.Sh COMPATIBILITY +This provider is not compatible with the +.Nm io +provider found in Solaris, as its probes use native +.Fx +argument types. +.Sh SEE ALSO +.Xr dtrace 1 , +.Xr devstat 9 , +.Xr SDT 9 +.Sh HISTORY +The +.Nm io +provider first appeared in +.Fx +9.2 and 10.0. +.Sh AUTHORS +This manual page was written by +.An Mark Johnston Aq Mt markj@FreeBSD.org . +.Sh BUGS +The +.Fn io:::wait-start +and +.Fn io:::wait-done +probes are not currently implemented on +.Fx . |