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kdump(1) [netbsd man page]

KDUMP(1)						    BSD General Commands Manual 						  KDUMP(1)

kdump -- display kernel trace data SYNOPSIS
kdump [-dlNnRT] [-e emulation] [-f file] [-m maxdata] [-p pid] [-t trstr] [-x | -X size] [file] DESCRIPTION
kdump displays the kernel trace files produced with ktrace(1) in human readable format. The file ktrace.out in the current directory is dis- played, unless either the -f option is used, or a file name is supplied as the last argument. The options are as follows: -d Display all numbers in decimal. -e emulation If an emulation of a process is unknown, interpret system call maps assuming the named emulation instead of default "netbsd". -f file Display the specified file instead of ktrace.out. -l Loop reading the trace file, once the end-of-file is reached, waiting for more data. -m maxdata Display at most maxdata bytes when decoding I/O. -N Suppress system call number-to-name translation. -n Suppress ad hoc translations. Normally kdump tries to decode many system calls into a more human readable format. For example, ioctl(2) values are replaced with the macro name and errno values are replaced with the strerror(3) string. Suppressing this feature yields a more consistent output format and is easily amenable to further processing. -p pid Only display records from the trace file that are for the indicated pid. -R Display relative timestamps (time since previous entry). -T Display absolute timestamps for each entry (seconds since epoch). -t trstr Restrict display to the specified set of kernel trace points. The default is to display everything in the file. See the -t option of ktrace(1). -x Display GIO data in hex and ascii instead of vis(3) format. -X size Same as -x but display hex values by groups of size bytes. Supported values are 1, 2, 4, 8, and 16. SEE ALSO
ktrace(1) HISTORY
The kdump command appears in 4.4BSD. BSD
November 15, 2003 BSD

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KTRACE(1)						    BSD General Commands Manual 						 KTRACE(1)

ktrace -- enable kernel process tracing SYNOPSIS
ktrace [-aCcdi] [-f trfile] [-g pgrp | -p pid] [-t trstr] ktrace [-adi] [-f trfile] [-t trstr] command DESCRIPTION
The ktrace utility enables kernel trace logging for the specified processes. Kernel trace data is logged to the file ktrace.out. The kernel operations that are traced include system calls, namei translations, signal processing, and I/O. Once tracing is enabled on a process, trace data will be logged until either the process exits or the trace point is cleared. A traced process can generate enormous amounts of log data quickly; It is strongly suggested that users memorize how to disable tracing before attempting to trace a process. The following command is sufficient to disable tracing on all user-owned processes, and, if executed by root, all processes: $ ktrace -C The trace file is not human readable; use kdump(1) to decode it. The utility may be used only with a kernel that has been built with the ``KTRACE'' option in the kernel configuration file. The options are: -a Append to the trace file instead of recreating it. -C Disable tracing on all user-owned processes, and, if executed by root, all processes in the system. -c Clear the specified trace points associated with the given file or processes. -d Descendants; perform the operation for all current children of the designated processes. -f trfile Log trace records to trfile instead of ktrace.out. -g pgid Enable (disable) tracing on all processes in the process group (only one -g flag is permitted). -i Inherit; pass the trace flags to all future children of the designated processes. -p pid Enable (disable) tracing on the indicated process id (only one -p flag is permitted). -t trstr Specify the list of trace points to enable or disable, one per letter. If an explicit list is not specified, the default set of trace points is used. The following trace points are supported: c trace system calls f trace page faults i trace I/O n trace namei translations p trace capability check failures s trace signal processing t trace various structures u userland traces w context switches y trace sysctl(3) requests + trace the default set of trace points - c, i, n, p, s, t, u, y command Execute command with the specified trace flags. The -p, -g, and command options are mutually exclusive. EXAMPLES
# trace all kernel operations of process id 34 $ ktrace -p 34 # trace all kernel operations of processes in process group 15 and # pass the trace flags to all current and future children $ ktrace -idg 15 # disable all tracing of process 65 $ ktrace -cp 65 # disable tracing signals on process 70 and all current children $ ktrace -t s -cdp 70 # enable tracing of I/O on process 67 $ ktrace -ti -p 67 # run the command "w", tracing only system calls $ ktrace -tc w # disable all tracing to the file "tracedata" $ ktrace -c -f tracedata # disable tracing of all user-owned processes $ ktrace -C SEE ALSO
kdump(1) HISTORY
The ktrace command appeared in 4.4BSD. BUGS
Only works if trfile is a regular file. BSD
August 26, 2014 BSD
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