Annotation of wikisrc/how_to_enable_and_run_dtrace.mdwn, revision 1.3

1.1       wiki        1: DTrace is a Dynamic Tracing framework developed by Sun and ported to NetBSD. It enables extensive instrumentation of the kernel and user space. See the [DTrace Community Page](http://hub.opensolaris.org/bin/view/Community+Group+dtrace/WebHome) for more information. Also see [DTrace Introduction](http://wikis.sun.com/display/DTrace/Introduction).
                      2: 
1.3     ! wiz         3: DTrace is a work-in-progress effort and it is for amd64 and i386 systems only. Two providers are available; the Statically Defined Tracing (SDT) provider and the Function Boundary Tracer (FBT) provider.
1.1       wiki        4: 
1.2       wiki        5: ###Building DTrace
1.1       wiki        6: 
                      7: You need the following options in your kernel:
                      8: 
                      9:     options         INSECURE
                     10:     options         KDTRACE_HOOKS   # DTrace support
                     11:     options         MODULAR
                     12: 
                     13: Note: Make sure "options DEBUG" is not defined. There is currently a problem where the debug symbols overwrite the CTF symbols.  Its not fatal, but your DTrace scripts will not recognize any symbols in the kernel rendering them unusable.
                     14: 
                     15: You also need to build distribution with the options MKMODULAR=yes and MKDTRACE=yes.
                     16: 
1.2       wiki       17: ###Running hello world
1.1       wiki       18: 
                     19: Load the solaris and dtrace modules, and the SDT (Statically Defined Tracing) and FBT (Function Boundary Tracing) modules:
                     20: 
                     21:     modload solaris
                     22:     modload dtrace
                     23:     modload sdt
                     24:     modload fbt
                     25: 
                     26: Make the dtrace device node:
                     27: 
                     28:     mkdir /dev/dtrace
                     29:     mknod /dev/dtrace/dtrace c dtrace 0
                     30: 
                     31: List the dtrace probes
                     32: 
                     33:     dtrace -l
                     34: 
                     35:        ID   PROVIDER            MODULE                          FUNCTION NAME
                     36:         1     dtrace                                                     BEGIN
                     37:         2     dtrace                                                     END
                     38:         3     dtrace                                                     ERROR
                     39:         4        fbt            netbsd             AcpiAcquireGlobalLock entry
                     40:         5        fbt            netbsd             AcpiAcquireGlobalLock return
                     41:         6        fbt            netbsd             AcpiAllocateRootTable entry
                     42:         7        fbt            netbsd                    AcpiAttachData entry
                     43:         . 
                     44:         .
                     45:     29129        fbt           solaris                   zfs_vop_getattr entry 
                     46:     29130        fbt           solaris                   zfs_vop_getattr return
                     47:     29131       proc                                                     create
                     48:     29132       proc                                                     exec 
                     49:         .
                     50:         .
                     51:     29140       proc                                                     lwp_start
                     52:     29141       proc                                                     lwp_exit
                     53: 
                     54: Put the following into the file hello.d
                     55: 
                     56:     BEGIN
                     57:     {
                     58:         trace("Hello world");
                     59:         exit(0);
                     60:     }
                     61: 
                     62: Run the hello world script:
                     63: 
                     64:     dtrace -s hello.d
                     65:     
                     66:     dtrace: script './hello.d' matched 1 probe
                     67:     CPU     ID                    FUNCTION:NAME
                     68:       0      1                           :BEGIN   Hello world
                     69: 
                     70: A more complex example that traces the execution of a sleep operation in the kernel:
                     71: 
                     72:     #pragma D option flowindent
                     73:     
                     74:     fbt::syscall:entry
                     75:     /execname == "sleep" && guard++ == 0/
                     76:     {
                     77:             self->traceme = 1;
                     78:             printf("fd: %d", arg0);
                     79:     }
                     80:     
                     81:     fbt:::
                     82:     /self->traceme/
                     83:     {}
                     84: 
                     85:     fbt::syscall:return
                     86:     /self->traceme/
                     87:     {
                     88:             self->traceme = 0;
                     89:             exit(0);
                     90:     }
                     91: 
                     92: Start the script running (dtrace -s scriptname.d) and then execute a sleep 2 in another shell.

CVSweb for NetBSD wikisrc <wikimaster@NetBSD.org> software: FreeBSD-CVSweb