a pair of records similar to syscall entry and return that a user can use to determine how long page faults take. The new ktrace records are enabled via the 'p' trace type, and are enabled in the default set of trace points. Reviewed by: kib MFC after: 2 weeks
184 lines
5.9 KiB
Groff
184 lines
5.9 KiB
Groff
.\" Copyright (c) 1990, 1993
|
|
.\" The Regents of the University of California. 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.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
|
|
.\"
|
|
.\" @(#)kdump.1 8.1 (Berkeley) 6/6/93
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd April 5, 2012
|
|
.Dt KDUMP 1
|
|
.Os
|
|
.Sh NAME
|
|
.Nm kdump
|
|
.Nd display kernel trace data
|
|
.Sh SYNOPSIS
|
|
.Nm
|
|
.Op Fl dEnlHRsTA
|
|
.Op Fl f Ar trfile
|
|
.Op Fl m Ar maxdata
|
|
.Op Fl p Ar pid
|
|
.Op Fl t Ar trstr
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
command displays the kernel trace files produced with
|
|
.Xr ktrace 1
|
|
in human readable format.
|
|
By default, the file
|
|
.Pa ktrace.out
|
|
in the current directory is displayed.
|
|
.Pp
|
|
The options are as follows:
|
|
.Bl -tag -width Fl
|
|
.It Fl d
|
|
Display all numbers in decimal.
|
|
.It Fl E
|
|
Display elapsed timestamps (time since beginning of trace).
|
|
.It Fl f Ar trfile
|
|
Display the specified file instead of
|
|
.Pa ktrace.out .
|
|
.It Fl H
|
|
List the thread ID (tid) of the thread with each trace record, if available.
|
|
If no thread ID is available, 0 will be printed.
|
|
.It Fl l
|
|
Loop reading the trace file, once the end-of-file is reached, waiting for
|
|
more data.
|
|
.It Fl m Ar maxdata
|
|
Display at most
|
|
.Ar maxdata
|
|
bytes when decoding
|
|
.Tn I/O .
|
|
.It Fl n
|
|
Suppress ad hoc translations.
|
|
Normally
|
|
.Nm
|
|
tries to decode many system calls into a more human readable format.
|
|
For example,
|
|
.Xr ioctl 2
|
|
values are replaced with the macro name and
|
|
.Va errno
|
|
values are replaced with the
|
|
.Xr strerror 3
|
|
string.
|
|
Suppressing this feature yields a more consistent output format and is
|
|
easily amenable to further processing.
|
|
.It Fl p Ar pid
|
|
Display only trace events that correspond to the process
|
|
.Ar pid .
|
|
This may be useful when there are multiple processes recorded in the
|
|
same trace file.
|
|
.It Fl R
|
|
Display relative timestamps (time since previous entry).
|
|
.It Fl r
|
|
When decoding STRU records, display structure members such as UIDs,
|
|
GIDs, dates etc. symbolically instead of numerically.
|
|
.It Fl s
|
|
Suppress display of I/O data.
|
|
.It Fl T
|
|
Display absolute timestamps for each entry (seconds since epoch).
|
|
.It Fl A
|
|
Display description of the ABI of traced process.
|
|
.It Fl t Ar trstr
|
|
See the
|
|
.Fl t
|
|
option of
|
|
.Xr ktrace 1 .
|
|
.El
|
|
.Pp
|
|
The output format of
|
|
.Nm
|
|
is line oriented with several fields.
|
|
The example below shows a section of a kdump generated by the following
|
|
commands:
|
|
.Bd -literal -offset indent
|
|
?> ktrace echo "ktrace"
|
|
|
|
?> kdump
|
|
|
|
85045 echo CALL writev(0x1,0x804b030,0x2)
|
|
85045 echo GIO fd 1 wrote 7 bytes
|
|
"ktrace
|
|
"
|
|
85045 echo RET writev 7
|
|
.Ed
|
|
.Pp
|
|
The first field is the PID of the process being traced.
|
|
The second field is the name of the program being traced.
|
|
The third field is the operation that the kernel performed
|
|
on behalf of the process.
|
|
If thread IDs are being printed, then an additional thread ID column will be
|
|
added to the output between the PID field and program name field.
|
|
.Pp
|
|
In the first line above, the kernel executes the
|
|
.Xr writev 2
|
|
system call on behalf of the process so this is a
|
|
.Li CALL
|
|
operation.
|
|
The fourth field shows the system call that was executed,
|
|
including its arguments.
|
|
The
|
|
.Xr writev 2
|
|
system call takes a file descriptor, in this case 1, or standard
|
|
output, then a pointer to the iovector to write, and the number of
|
|
iovectors that are to be written.
|
|
In the second line we see the operation was
|
|
.Li GIO ,
|
|
for general I/O, and that file descriptor 1 had
|
|
seven bytes written to it.
|
|
This is followed by the seven bytes that were written, the string
|
|
.Qq Li ktrace
|
|
with a carriage return and line feed.
|
|
The last line is the
|
|
.Li RET
|
|
operation, showing a return from the kernel, what system call we are
|
|
returning from, and the return value that the process received.
|
|
Seven bytes were written by the
|
|
.Xr writev 2
|
|
system call, so 7 is the return value.
|
|
.Pp
|
|
The possible operations are:
|
|
.Bl -column -offset indent ".Li CALL" ".No data from user process"
|
|
.It Sy Name Ta Sy Operation Ta Sy Fourth field
|
|
.It Li CALL Ta enter syscall Ta syscall name and arguments
|
|
.It Li RET Ta return from syscall Ta syscall name and return value
|
|
.It Li NAMI Ta file name lookup Ta path to file
|
|
.It Li GIO Ta general I/O Ta fd, read/write, number of bytes
|
|
.It Li PSIG Ta signal Ta signal name, handler, mask, code
|
|
.It Li CSW Ta context switch Ta stop/resume user/kernel
|
|
.It Li USER Ta data from user process Ta the data
|
|
.It Li STRU Ta various syscalls Ta structure
|
|
.It Li SCTL Ta Xr sysctl 3 requests Ta MIB name
|
|
.It Li PFLT Ta enter page fault Ta fault address and type
|
|
.It Li PRET Ta return from page fault Ta fault result
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr ktrace 1
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
command appeared in
|
|
.Bx 4.4 .
|