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version 1.15, 2017/03/22 15:43:09	version 1.26, 2018/07/22 17:18:06
Line 8 Also see [DTrace Introduction](http://dt	Line 8 Also see [DTrace Introduction](http://dt
DTrace is a work-in-progress effort and it is for x86 systems and some arm boards.	DTrace is a work-in-progress effort and it is for x86 systems and some arm boards.

* i386 and amd64	* i386 and amd64
* earm* (evbarm and armv4 based ports (armv4 side requires further testing but system is built with CTF)	* earm* (evbarm and armv4 based ports)

## Supported providers	## Supported providers

* SDT: Statically Defined Tracing	* DTrace: What to do when a script BEGINs, ENDs, ERRORs
* FBT: Function Boundary Tracing	* FBT: Function Boundary Tracing
	* IO: Disk I/O
* Lockstat: Kernel Lock Statistics	* Lockstat: Kernel Lock Statistics
	* Proc: Process and thread related events
* Profile: Time based interrupt event source for Profiling	* Profile: Time based interrupt event source for Profiling
	* SDT: Statically Defined Tracing
* Syscall: System Calls	* Syscall: System Calls
* Syscall Linux (32bit & 64 bit): System calls via the Linux binary emulation layer	* Syscall Linux (32bit & 64 bit): System calls via the Linux binary emulation layer
	* VFS: Filesystem operations (confined to namecache events at time of writing - 8.99.22)

## TODO for netbsd-7	## TODO for netbsd-7

Line 25 DTrace is a work-in-progress effort and	Line 29 DTrace is a work-in-progress effort and
* Determine whether the profile module works and list it here.	* Determine whether the profile module works and list it here.
* Integrate [[riz\|users/riz]]'s syscall provider patch.	* Integrate [[riz\|users/riz]]'s syscall provider patch.

## TODO for netbsd-6

Need to identify changes to pull up to netbsd-6 and pull them up.
Candidates:

* Profile provider.

# How to use	# How to use

## Building DTrace	## Building DTrace
Line 42 You need the following options in your k	Line 39 You need the following options in your k
options MODULAR	options MODULAR

Optionally:	Optionally:

options INSECURE # permit modules to loaded from user space once system has gone multiuser and securelevel has been raised.	options INSECURE # permit modules to loaded from user space once system has gone multiuser and securelevel has been raised.

A Distribution needs to be built with the options `MKDTRACE=yes` and `MKCTF=yes`, this is taken care of automatically and doesn't need to be specified manually. The list of platforms it is applied to automatically is set in `src/share/mk/bsd.own.mk`	A Distribution needs to be built with the options `MKDTRACE=yes` and `MKCTF=yes`, this is taken care of automatically and doesn't need to be specified manually. The list of platforms it is applied to automatically is set in `src/share/mk/bsd.own.mk`

Set the system to load the solaris and dtrace related modules in `/etc/modules.conf`, for a list of available modules, see `/stand/$MACHINE/$VERSION/modules/`	Set the system to load the solaris and dtrace related modules in `/etc/modules.conf`, for a list of available modules, see `/stand/$MACHINE/$VERSION/modules/`

	For example, add the following to `/etc/modules.conf` (the file may not exist already on a system):

solaris	- `solaris`
dtrace	- `dtrace`
dtrace_sdt	- `dtrace_fbt`
dtrace_fbt	- `dtrace_lockstat`
dtrace_lockstat	- `dtrace_profile`
dtrace_profile	- `dtrace_sdt`
dtrace_syscall	- `dtrace_syscall`
	- `dtrace_syscall_linux`

A `dtrace` device node is created automatically in `/dev/dtrace` when the modules are loaded into place.	A `dtrace` device node is created automatically in `/dev/dtrace` when the modules are loaded into place.

Line 82 List the dtrace probes	Line 83 List the dtrace probes
29141 proc lwp_exit	29141 proc lwp_exit


## Running hello world	## Running hello world

Put the following into the file hello.d:	Put the following into the file hello.d:

Line 102 Run the hello world script:	Line 103 Run the hello world script:
0 1 :BEGIN Hello world	0 1 :BEGIN Hello world


A more complex example that traces the execution of a sleep operation	## A more complex example

	The following script traces the execution of a sleep operation
in the kernel. Put it in sleep.d:	in the kernel. Put it in sleep.d:

#pragma D option flowindent	#pragma D option flowindent

fbt::syscall:entry	syscall::nanosleep:entry
/execname == "sleep" && guard++ == 0/	/execname == "sleep" && guard++ == 0/
{	{
self->traceme = 1;	self->traceme = 1;
printf("fd: %d", arg0);
}	}

fbt::syscall:entry /self->traceme/ {}	fbt:::
	/self->traceme/
fbt::syscall:return	{}

	syscall::nanosleep:return
/self->traceme/	/self->traceme/
{	{
self->traceme = 0;	self->traceme = 0;
exit(0);	exit(0);
}	}


Start the script running (dtrace -s sleep.d) and then execute a "sleep 2" in another shell.	Start the script running:

	dtrace -s sleep.d

	This will take a while as the script instruments every function in the
	kernel. When it's ready, it will print a message like "dtrace: script
	'sleep.d' matched 59268 probes". Then execute a "sleep 2" in another
	shell.

	## Tools included in base

	Starting with NetBSD-8, on builds where `MKDTRACE=yes` is set, scripts from
	[Brendan Gregg's DTrace toolkit](https://github.com/opendtrace/toolkit/) are installed in base as standard.

	At present, the following scripts are installed in `/usr/sbin`:

	- `dtruss` - An implementation of the truss utility in DTrace which traces the system calls
	made by a process
	- `execsnoop` - snoop on execution of processes as they occur
	- `opensnoop` - snoop on openning of files as they occur
	- `procsystime` - print process system call time details.

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