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Annotation of wikisrc/tutorials/how_to_enable_and_run_dtrace.mdwn, revision 1.12

1.4       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://dtrace.org) for more information. Also see [DTrace Introduction](http://dtrace.org/guide/preface.html). 
1.2       schmonz     2: 
1.5       wiki        3: # Current status
1.2       schmonz     4: 
1.5       wiki        5: ## Supported platforms
                      6: 
                      7: DTrace is a work-in-progress effort and it is for x86 systems and some arm boards.
                      8: 
                      9: * i386 and amd64
                     10: * evbarm
                     11:     * BEAGLEBONE and SHEEVAPLUG
                     12: 
                     13: ## Supported providers
                     14: 
                     15: * SDT: Statically Defined Tracing
                     16: * FBT: Function Boundary Tracing
1.2       schmonz    17: 
                     18: You can currently run a hello world DScript. 
                     19: 
1.6       riastrad   20: ## TODO for netbsd-7
                     21: 
                     22: * Measure effect of `options KDTRACE_HOOKS` on system performance.
                     23: * Determine whether the profile module works and list it here.
1.7       riastrad   24: * Integrate [[riz|users/riz]]'s syscall provider patch.
1.6       riastrad   25: 
                     26: ## TODO for netbsd-6
                     27: 
                     28: Need to identify changes to pull up to netbsd-6 and pull them up.
                     29: Candidates:
                     30: 
                     31: * Profile provider.
                     32: 
1.5       wiki       33: # How to use
                     34: 
1.2       schmonz    35: ##  Building DTrace 
                     36: 
                     37: You need the following options in your kernel: 
                     38:     
                     39:     options         INSECURE
1.10      wiz        40:     options         KDTRACE_HOOKS   # kernel DTrace hooks
1.2       schmonz    41:     options         MODULAR
                     42:     
                     43: 
1.8       riastrad   44: You also need to build distribution with the options MKDTRACE=yes.
1.2       schmonz    45: 
                     46: ##  Running hello world 
                     47: 
                     48: Load the solaris and dtrace modules, and the SDT (Statically Defined Tracing) and FBT (Function Boundary Tracing) modules: 
                     49:     
                     50:     modload solaris
                     51:     modload dtrace
1.12    ! wiz        52:     modload dtrace_sdt
        !            53:     modload dtrace_fbt
1.2       schmonz    54:     
                     55: 
                     56: Make the dtrace device node: 
                     57:     
1.11      wiz        58:     cd /dev
                     59:     sh MAKEDEV dtrace
1.2       schmonz    60:     
                     61: 
                     62: List the dtrace probes 
                     63:     
                     64:     dtrace -l
                     65:     
                     66:        ID   PROVIDER            MODULE                          FUNCTION NAME
                     67:         1     dtrace                                                     BEGIN
                     68:         2     dtrace                                                     END
                     69:         3     dtrace                                                     ERROR
                     70:         4        fbt            netbsd             AcpiAcquireGlobalLock entry
                     71:         5        fbt            netbsd             AcpiAcquireGlobalLock return
                     72:         6        fbt            netbsd             AcpiAllocateRootTable entry
                     73:         7        fbt            netbsd                    AcpiAttachData entry
                     74:         . 
                     75:         .
                     76:     29129        fbt           solaris                   zfs_vop_getattr entry 
                     77:     29130        fbt           solaris                   zfs_vop_getattr return
                     78:     29131       proc                                                     create
                     79:     29132       proc                                                     exec 
                     80:         .
                     81:         .
                     82:     29140       proc                                                     lwp_start
                     83:     29141       proc                                                     lwp_exit
                     84:     
                     85: 
                     86:   
                     87: 
                     88: 
1.9       wiz        89: Put the following into the file hello.d:
1.2       schmonz    90:     
                     91:     BEGIN
                     92:     {
                     93:         trace("Hello world");
                     94:         exit(0);
                     95:     }
                     96:     
                     97: 
                     98: Run the hello world script: 
                     99:     
                    100:     dtrace -s hello.d
                    101:     
                    102:     dtrace: script './hello.d' matched 1 probe
                    103:     CPU     ID                    FUNCTION:NAME
                    104:       0      1                           :BEGIN   Hello world
                    105:     
                    106: 
1.9       wiz       107: A more complex example that traces the execution of a sleep operation
                    108: in the kernel. Put it in sleep.d:
1.2       schmonz   109:     
                    110:     #pragma D option flowindent
                    111:     
                    112:     fbt::syscall:entry
                    113:     /execname == "sleep" && guard++ == 0/
                    114:     {
                    115:             self->traceme = 1;
                    116:             printf("fd: %d", arg0);
                    117:     }
                    118:     
1.9       wiz       119:     fbt::syscall:entry /self->traceme/ {}
1.2       schmonz   120:     
                    121:     fbt::syscall:return
                    122:     /self->traceme/
                    123:     {
                    124:             self->traceme = 0;
                    125:             exit(0);
                    126:     }
                    127:     
                    128: 
1.9       wiz       129: Start the script running (dtrace -s sleep.d) and then execute a "sleep 2" in another shell.