diff --git a/Makefile.in b/Makefile.in
index 58609f63fe..f328d2ad34 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -52,7 +52,6 @@ debugflags = @debugflags@
 warnflags = @warnflags@
 XCFLAGS = -I. -I$(arch_hdrdir) -I$(hdrdir) -I$(srcdir) @XCFLAGS@
 CPPFLAGS = @CPPFLAGS@
-CPPOUTFILE = @CPPOUTFILE@
 LDFLAGS = @STATIC@ $(CFLAGS) @LDFLAGS@
 EXTLDFLAGS = 
 XLDFLAGS = @XLDFLAGS@ $(EXTLDFLAGS)
@@ -67,10 +66,6 @@ ARCHMINIOBJS = @MINIOBJS@
 BUILTIN_ENCOBJS = @BUILTIN_ENCOBJS@
 BUILTIN_TRANSSRCS = @BUILTIN_TRANSSRCS@
 BUILTIN_TRANSOBJS = @BUILTIN_TRANSOBJS@
-DTRACE_OBJ      = @DTRACE_OBJ@
-MINIDTRACE_OBJ  = @MINIDTRACE_OBJ@
-GOLFDTRACE_OBJ  = @GOLFDTRACE_OBJ@
-LIBRUBY_DTRACE_OBJ  = @LIBRUBY_DTRACE_OBJ@
 
 RUBY_BASE_NAME=@RUBY_BASE_NAME@
 RUBY_INSTALL_NAME=@RUBY_INSTALL_NAME@
@@ -97,7 +92,6 @@ LIBRUBYARG_STATIC = @LIBRUBYARG_STATIC@
 LIBRUBYARG_SHARED = @LIBRUBYARG_SHARED@
 
 THREAD_MODEL  = @THREAD_MODEL@
-TRACING_MODEL = @TRACING_MODEL@
 
 PREP          = @PREP@
 ARCHFILE      = @ARCHFILE@
@@ -121,10 +115,8 @@ IFCHANGE      = $(srcdir)/tool/ifchange
 SET_LC_MESSAGES = env LC_MESSAGES=C
 OBJDUMP       = @OBJDUMP@
 OBJCOPY       = @OBJCOPY@
-DTRACE        = @DTRACE@
 VCS           = @VCS@
 VCSUP         = @VCSUP@
-DOXYGEN	      = @DOXYGEN@
 
 OBJEXT        = @OBJEXT@
 ASMEXT        = S
@@ -147,37 +139,28 @@ all:
 
 miniruby$(EXEEXT):
 		@-if test -f $@; then $(MV) -f $@ $@.old; $(RM) $@.old; fi
-		$(PURIFY) $(CC) $(LDFLAGS) $(XLDFLAGS) $(MAINLIBS) $(MAINOBJ) $(MINIOBJS) $(COMMONOBJS) $(DMYEXT) $(MINIDTRACE_OBJ) $(LIBS) $(OUTFLAG)$@
-$(MINIDTRACE_OBJ): $(arch_hdrdir)/ruby/dtrace.d $(NORMALMAINOBJ) $(MINIOBJS) $(COMMONOBJS) $(DMYEXT)
-		$(DTRACE) -G -o $@ -s $(arch_hdrdir)/ruby/dtrace.d $(NORMALMAINOBJ) $(MINIOBJS) $(COMMONOBJS) $(DMYEXT)
+		$(PURIFY) $(CC) $(LDFLAGS) $(XLDFLAGS) $(MAINLIBS) $(MAINOBJ) $(MINIOBJS) $(COMMONOBJS) $(DMYEXT) $(LIBS) $(OUTFLAG)$@
 
 $(PROGRAM):
 		@$(RM) $@
-		$(PURIFY) $(CC) $(LDFLAGS) $(XLDFLAGS) $(MAINLIBS) $(MAINOBJ) $(EXTOBJS) $(DTRACE_OBJ) $(LIBRUBYARG) $(LIBS) $(OUTFLAG)$@
-$(DTRACE_OBJ): $(arch_hdrdir)/ruby/dtrace.d $(MAINOBJ) $(EXTOBJS)
-		$(DTRACE) -G -o $@ -s $(arch_hdrdir)/ruby/dtrace.d $(MAINOBJ) $(EXTOBJS)
-$(GOLFDTRACE_OBJ): $(arch_hdrdir)/ruby/dtrace.d $(GOLFOBJS) $(EXTOBJS)
-		$(DTRACE) -G -o $@ -s $(arch_hdrdir)/ruby/dtrace.d $(GOLFOBJS) $(EXTOBJS)
+		$(PURIFY) $(CC) $(LDFLAGS) $(XLDFLAGS) $(MAINLIBS) $(MAINOBJ) $(EXTOBJS) $(LIBRUBYARG) $(LIBS) $(OUTFLAG)$@
 
 # We must `rm' the library each time this rule is invoked because "updating" a
 # MAB library on Apple/NeXT (see --enable-fat-binary in configure) is not
 # supported.
 $(LIBRUBY_A):
 		@$(RM) $@
-		$(AR) $(ARFLAGS) $@ $(OBJS) $(DMYEXT) $(LIBRUBY_DTRACE_OBJ)
+		$(AR) $(ARFLAGS) $@ $(OBJS) $(DMYEXT)
 		@-$(RANLIB) $@ 2> /dev/null || true
 
 $(LIBRUBY_SO):
 		@-$(PRE_LIBRUBY_UPDATE)
-		$(LDSHARED) $(DLDFLAGS) $(OBJS) $(DLDOBJS) $(LIBRUBY_DTRACE_OBJ) $(SOLIBS) $(OUTFLAG)$@
+		$(LDSHARED) $(DLDFLAGS) $(OBJS) $(DLDOBJS) $(SOLIBS) $(OUTFLAG)$@
 		-$(OBJCOPY) -w -L '@EXPORT_PREFIX@Init_*' -L '@EXPORT_PREFIX@*_threadptr_*' $@
 		@-$(MINIRUBY) -e 'ARGV.each{|link| File.delete link if File.exist? link; \
 						  File.symlink "$(LIBRUBY_SO)", link}' \
 				$(LIBRUBY_ALIASES) || true
 
-$(LIBRUBY_DTRACE_OBJ): $(arch_hdrdir)/ruby/dtrace.d $(OBJS) $(DMYEXT)
-		$(DTRACE) -G -o $@ -s $(arch_hdrdir)/ruby/dtrace.d $(OBJS) $(DMYEXT)
-
 fake: $(arch)-fake.rb
 $(arch)-fake.rb: config.status
 		@./config.status --file=$@:$(srcdir)/template/fake.rb.in
@@ -205,22 +188,6 @@ $(srcdir)/configure: $(srcdir)/configure.in
 
 incs: id.h
 
-$(arch_hdrdir)/ruby/trace_dtrace.h: $(arch_hdrdir)/ruby/dtrace.d
-	$(DTRACE) -h -o $@ -s $(arch_hdrdir)/ruby/dtrace.d
-
-# NOTE: dtrace is not used on cross compiling
-$(arch_hdrdir)/ruby/dtrace.d: $(srcdir)/defs/dtrace.d
-	@echo '#include <limits.h>' > conftest.c
-	@echo '#define RUBY_TRACE_H' >> conftest.c
-	@echo '#include "ruby/ruby.h"' >> conftest.c
-	@echo 'int main(){ printf("%d", SIZEOF_VALUE * CHAR_BIT); return 0; }' >> conftest.c
-	@$(CC) $(CFLAGS) $(XCFLAGS) $(CPPFLAGS) -c $(COUTFLAG)conftest.o conftest.c 
-	$(CC) $(LDFLAGS) $(XLDFLAGS) conftest.o $(LIBS) $(OUTFLAG)conftest
-	@$(CP) $(srcdir)/defs/dtrace.d dtrace.c
-	$(CPP) $(CPPFLAGS) -DBITSIZE_OF_VALUE=`./conftest` dtrace.c $(CPPOUTFILE)
-	$(MV) conftest.i $@
-	@$(RM) conftest conftest.[co] dtrace.c
-
 # Things which should be considered:
 # * with gperf v.s. without gperf
 # * committers may have various versions of gperf
diff --git a/NEWS b/NEWS
index 55289d9bdc..d94b43ecbc 100644
--- a/NEWS
+++ b/NEWS
@@ -222,10 +222,6 @@ with all sufficient information, see the ChangeLog file.
     * Pathname#realdirpath
     * Pathname#each_child
 
-* probe
-  new library.
-  * Kernel#fire_probe
-
 * Readline
   * new methods:
     * Readline.set_screen_size
@@ -270,14 +266,6 @@ with all sufficient information, see the ChangeLog file.
   Unicode semantics
 * $: no longer includes the current directory, use require_relative
 
-=== Tracing (experimental)
-
-* Runtime tracing is supported. Currently implemented on top of dtrace.
-  You can trace a ruby program without any modification if your platform
-  supports dtrace USDT.
-
-  This feature is experimental. The semantics of probes will possibly change.
-
 === Compilation options
 
 * --program-prefix and --program-suffix no longer act on the shared object
@@ -289,8 +277,6 @@ with all sufficient information, see the ChangeLog file.
 * --with-arch is added for universal binary, instead of
   --enable-fat-binary option.
 
-* --with-tracing-model is added for choosing a particular tracing mechanism.
-
 === Compatibility issues (excluding feature bug fixes)
 
   * Enumerator#rewind
diff --git a/common.mk b/common.mk
index 1b86aedb9f..45d03c8f7d 100644
--- a/common.mk
+++ b/common.mk
@@ -142,11 +142,11 @@ loadpath: $(PREP) PHONY
 
 $(PREP): $(MKFILES)
 
-miniruby$(EXEEXT): config.status $(NORMALMAINOBJ) $(MINIOBJS) $(COMMONOBJS) $(DMYEXT) $(ARCHFILE) $(MINIDTRACE_OBJ)
+miniruby$(EXEEXT): config.status $(NORMALMAINOBJ) $(MINIOBJS) $(COMMONOBJS) $(DMYEXT) $(ARCHFILE)
 
 GORUBY = go$(RUBY_INSTALL_NAME)
-golf: $(LIBRUBY) $(GOLFOBJS) $(GOLFDTRACE_OBJ) PHONY
-	$(MAKE) $(MFLAGS) MAINOBJ="$(GOLFOBJS)" DTRACE_OBJ="$(GOLFDTRACE_OBJ)" PROGRAM=$(GORUBY)$(EXEEXT) program
+golf: $(LIBRUBY) $(GOLFOBJS) PHONY
+	$(MAKE) $(MFLAGS) MAINOBJ="$(GOLFOBJS)" PROGRAM=$(GORUBY)$(EXEEXT) program
 capi: Doxyfile PHONY $(PREP)
 	@$(MAKEDIRS) doc/capi
 	@$(DOXYGEN)
@@ -157,9 +157,9 @@ Doxyfile: $(srcdir)/template/Doxyfile.tmpl $(PREP) $(srcdir)/tool/generic_erb.rb
 
 program: $(PROGRAM)
 
-$(PROGRAM): $(LIBRUBY) $(MAINOBJ) $(OBJS) $(EXTOBJS) $(DTRACE_OBJ) $(SETUP) $(PREP)
+$(PROGRAM): $(LIBRUBY) $(MAINOBJ) $(OBJS) $(EXTOBJS) $(SETUP) $(PREP)
 
-$(LIBRUBY_A):	$(OBJS) $(DMYEXT) $(LIBRUBY_DTRACE_OBJ) $(ARCHFILE)
+$(LIBRUBY_A):	$(OBJS) $(DMYEXT) $(ARCHFILE)
 
 $(LIBRUBY_SO):	$(OBJS) $(DLDOBJS) $(LIBRUBY_A) $(PREP) $(LIBRUBY_SO_UPDATE) $(BUILTIN_ENCOBJS)
 
@@ -385,7 +385,6 @@ distclean: distclean-ext distclean-local distclean-enc distclean-golf distclean-
 distclean-local:: clean-local
 	@$(RM) $(MKFILES) rbconfig.rb yasmdata.rb encdb.h
 	@$(RM) config.cache config.log config.status config.status.lineno $(PRELUDES)
-	@$(RM) $(arch_hdrdir)/ruby/dtrace.d
 	@$(RM) *~ *.bak *.stackdump core *.core gmon.out $(PREP)
 distclean-ext:: PHONY
 distclean-golf: clean-golf
@@ -512,8 +511,7 @@ win32.$(OBJEXT): {$(VPATH)}win32.c $(RUBY_H_INCLUDES)
 ###
 
 RUBY_H_INCLUDES    = {$(VPATH)}ruby.h {$(VPATH)}config.h {$(VPATH)}defines.h \
-		     {$(VPATH)}intern.h {$(VPATH)}missing.h {$(VPATH)}st.h \
-		     {$(VPATH)}trace.h {$(VPATH)}trace_$(TRACING_MODEL).h
+		     {$(VPATH)}intern.h {$(VPATH)}missing.h {$(VPATH)}st.h
 ENCODING_H_INCLUDES= {$(VPATH)}encoding.h {$(VPATH)}oniguruma.h
 ID_H_INCLUDES      = {$(VPATH)}id.h
 VM_CORE_H_INCLUDES = {$(VPATH)}vm_core.h {$(VPATH)}vm_opts.h \
@@ -680,9 +678,6 @@ newline.$(OBJEXT): {$(VPATH)}newline.c {$(VPATH)}defines.h \
   {$(VPATH)}intern.h {$(VPATH)}missing.h {$(VPATH)}st.h \
   {$(VPATH)}transcode_data.h {$(VPATH)}ruby.h {$(VPATH)}config.h
 
-trace_none.h:
-	echo > $@
-
 INSNS2VMOPT = --srcdir="$(srcdir)"
 
 {$(VPATH)}minsns.inc: $(srcdir)/template/minsns.inc.tmpl
diff --git a/compile.c b/compile.c
index ea4268aee2..54b513c4c8 100644
--- a/compile.c
+++ b/compile.c
@@ -3569,7 +3569,6 @@ iseq_compile_each(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE * node, int poped)
 	    }
 	    ADD_INSNL(ret, nd_line(node), jump, label_miss);
 	    ADD_LABEL(ret, label_hit);
-	    ADD_TRACE(ret, nd_line(node), RUBY_EVENT_RESCUE);
 	    COMPILE(ret, "resbody body", resq->nd_body);
 	    if (iseq->compile_data->option->tailcall_optimization) {
 		ADD_INSN(ret, nd_line(node), nop);
diff --git a/configure.in b/configure.in
index c18f95da5d..d2a8228265 100644
--- a/configure.in
+++ b/configure.in
@@ -357,52 +357,6 @@ fi
 MAKEDIRS="$MKDIR_P"
 AC_SUBST(MAKEDIRS)
 
-AC_DEFUN([RUBY_DTRACE_POSTPROCESS],
-[AC_CACHE_CHECK(whether $DTRACE needs post processing, rb_cv_prog_dtrace_g,
-[
- echo "int main(void){ return 0; }" > conftest.c
- echo "provider conftest{};" > conftest_provider.d
- $CC $CFLAGS -c -o conftest.o conftest.c
- if $DTRACE -G -s conftest_provider.d conftest.o 2>/dev/null; then
-   rb_cv_prog_dtrace_g=yes
-   $1
- else
-   rb_cv_prog_dtrace_g=no
-   $2
- fi
- rm -f conftest.o conftest.c conftest_provider.d conftest_provider.o
-])
-])
-
-AC_DEFUN([RUBY_DTRACE_BSD_BROKEN],
-[AC_CACHE_CHECK(whether dtrace USDT is broken, rb_cv_dtrace_bsd_broken,
-[
-    cat <<EOF > conftest.c
-#define _DTRACE_VERSION 1
-#include "conftest_provider.h"
-int main(void)
-{
-    if (CONFTEST_FIRE_ENABLED()) CONFTEST_FIRE();
-    return 0;
-}
-EOF
-    echo "provider conftest{ probe fire(); };" > conftest_provider.d
-    $DTRACE -h -o conftest_provider.h -s conftest_provider.d
-    $CC $CFLAGS -c -o conftest.o conftest.c
-    if $DTRACE -G -o conftest_provider.o -s conftest_provider.d conftest.o >/dev/null 2>/dev/null; then
-        rb_cv_dtrace_bsd_broken=no
-        $2
-    else
-        rb_cv_dtrace_bsd_broken=yes
-        $1
-    fi
-    rm -f conftest.[co] conftest_provider.[dho]
-])
-])
-
-AC_CHECK_TOOL(DTRACE, dtrace)
-$DTRACE -l 1>/dev/null 2>/dev/null || DTRACE=""
-
 AC_CHECK_TOOL(DOT, dot)
 AC_CHECK_TOOL(DOXYGEN, doxygen)
 if test x"$DOXYGEN" = x; then
@@ -1069,7 +1023,6 @@ AC_CHECK_HEADERS(limits.h sys/file.h sys/ioctl.h sys/syscall.h\
 		 ucontext.h intrinsics.h langinfo.h locale.h sys/sendfile.h time.h \
 		 net/socket.h sys/socket.h)
 
-
 dnl Check additional types.
 RUBY_CHECK_SIZEOF(rlim_t, [int long "long long"], [], [
   #ifdef HAVE_SYS_TYPES_H
@@ -2112,54 +2065,6 @@ case "$target_os" in
     ;;
 esac
 
-AC_ARG_WITH(tracing-model,
-            AS_HELP_STRING([--with-tracing-model=MODEL], [use MODEL for tracing ruby's internal. [[auto]] (none|dtrace|auto)]),
-            [TRACING_MODEL=$withval], [TRACING_MODEL=auto])
-
-if test "${TRACING_MODEL}" = "auto"; then
-    if test x"$DTRACE" != x -a x"$cross_compiling" != xyes; then
-        RUBY_DTRACE_POSTPROCESS()
-        if test "$rb_cv_prog_dtrace_g" = 'yes'; then 
-            RUBY_DTRACE_BSD_BROKEN([TRACING_MODEL=none], [TRACING_MODEL=dtrace]) 
-        else
-            TRACING_MODEL=dtrace
-        fi
-    else
-        TRACING_MODEL=none
-    fi
-fi
-
-case "${TRACING_MODEL}" in
-    when(none)
-        AC_DEFINE(RUBY_TRACING_MODEL, RUBY_TRACING_MODEL_NONE, [none])
-        ;;
-    when(dtrace)
-        if test -z "$DTRACE"; then
-            AC_MSG_ERROR([dtrace(1) is missing])
-        elif test "$cross_compiling" = yes; then
-            AC_MSG_ERROR([--with-tracing-model=dtrace, however, cross compiling])
-        else
-            RUBY_DTRACE_POSTPROCESS()
-            if test "$rb_cv_prog_dtrace_g" = 'yes'; then 
-                RUBY_DTRACE_BSD_BROKEN([AC_MSG_ERROR([--with-tracing-model=dtrace, however, USDT is broken])], [])
-                DTRACE_OBJ='dtrace.$(OBJEXT)'
-                MINIDTRACE_OBJ='minidtrace.$(OBJEXT)'
-                GOLFDTRACE_OBJ='golfdtrace.$(OBJEXT)'
-                LIBRUBY_DTRACE_OBJ='libruby_dtrace.$(OBJEXT)'
-            fi
-        fi
-        AC_DEFINE(RUBY_TRACING_MODEL, RUBY_TRACING_MODEL_DTRACE, [dtrace])
-        AC_SUBST(DTRACE_OBJ)
-        AC_SUBST(MINIDTRACE_OBJ)
-        AC_SUBST(GOLFDTRACE_OBJ)
-        AC_SUBST(LIBRUBY_DTRACE_OBJ)
-        ;;
-    when(*)
-        AC_MSG_ERROR([unknown tracing model: ${TRACING_MODEL}])
-        ;;
-esac
-AC_SUBST(TRACING_MODEL)
-
 AC_ARG_WITH(soname,
 	AS_HELP_STRING([--with-soname=SONAME], [base name of shared library]),
 	[RUBY_SO_NAME=$withval], [RUBY_SO_NAME='$(RUBY_BASE_NAME)'])
@@ -2807,5 +2712,4 @@ AC_CONFIG_FILES(Makefile, [{
 [EXEEXT=$EXEEXT gnumake=$gnumake])
 AC_OUTPUT
 dnl }
-
 dnl }
diff --git a/defs/dtrace.d b/defs/dtrace.d
deleted file mode 100644
index 2983423d0b..0000000000
--- a/defs/dtrace.d
+++ /dev/null
@@ -1,41 +0,0 @@
-#ifdef BITSIZE_OF_VALUE
-#define DO_DEFINE_VALUE(sz) typedef uint ## sz ## _t VALUE
-#define DEFINE_VALUE(sz) DO_DEFINE_VALUE(sz)
-DEFINE_VALUE(BITSIZE_OF_VALUE);
-#else
-# error BITSIZE_OF_VALUE is not defined.
-#endif
-provider ruby {
-    probe method__entry(VALUE receiver, char *classname, char *methodname, char *sourcefile, int sourceline);
-    probe method__return(VALUE receiver, char *classname, char *methodname, char *sourcefile, int sourceline);
-    probe raise(VALUE exception, char *classname, char *sourcefile, int sourceline);
-    probe rescue(VALUE exception, char *classname, char *sourcefile, int sourceline);
-    probe line(char* sourcefile, int sourceline);
-
-    /* gc probes */
-    probe gc__begin();
-    probe gc__end();
-
-    /* threads and fibers */
-    probe thread__init(VALUE thread, char *sourcefile, int sourceline);
-    probe thread__term(VALUE thread, char *sourcefile, int sourceline);
-    probe thread__enter(VALUE thread, char *sourcefile, int sourceline);
-    probe thread__leave(VALUE thread, char *sourcefile, int sourceline);
-
-    /* Some initial memory type probes */
-    probe object__create(VALUE obj, char *classname, char *sourcefile, int sourceline);
-    probe object__free(VALUE obj);
-
-    /* VM proves */
-    probe insn__entry(char *insnname, VALUE *operands, char *sourcefile, int sourceline);
-    probe insn__return(char *insnname, VALUE *operands, char *sourcefile, int sourceline);
-
-    probe ruby__probe(char *name, char *data);
-};
-
-#pragma D attributes Evolving/Evolving/Common provider ruby provider 
-#pragma D attributes Private/Private/Unknown provider ruby module 
-#pragma D attributes Private/Private/Unknown provider ruby function 
-#pragma D attributes Evolving/Evolving/Unknown provider ruby name 
-#pragma D attributes Evolving/Evolving/Unknown provider ruby args 
-
diff --git a/eval.c b/eval.c
index 63f6a06901..c5a72dc609 100644
--- a/eval.c
+++ b/eval.c
@@ -424,13 +424,9 @@ rb_longjmp(int tag, volatile VALUE mesg)
 
     rb_trap_restore_mask();
 
-    if (tag == TAG_FATAL) {
-        if (UNLIKELY(TRACE_RAISE_ENABLED())) FIRE_RAISE(0, (char*)"fatal", (char*)file, line);
-    }
-    else {
+    if (tag != TAG_FATAL) {
 	EXEC_EVENT_HOOK(th, RUBY_EVENT_RAISE, th->cfp->self,
 			0 /* TODO: id */, 0 /* TODO: klass */);
-        if (UNLIKELY(TRACE_RAISE_ENABLED())) FIRE_RAISE(mesg, (char*)rb_class2name(CLASS_OF(mesg)), (char*)file, line);
     }
 
     rb_thread_raised_clear(th);
@@ -637,9 +633,6 @@ rb_rescue2(VALUE (* b_proc) (ANYARGS), VALUE data1,
 	    va_end(args);
 
 	    if (handle) {
-		if (UNLIKELY(TRACE_RESCUE_ENABLED())) {
-		    FIRE_RESCUE(th->errinfo, (char*)rb_class2name(CLASS_OF(th->errinfo)), (char*)"<unknown>", 0);
-		}
 		if (r_proc) {
 		    PUSH_TAG();
 		    if ((state = EXEC_TAG()) == 0) {
diff --git a/ext/probe/extconf.rb b/ext/probe/extconf.rb
deleted file mode 100644
index 41b4bc3dd3..0000000000
--- a/ext/probe/extconf.rb
+++ /dev/null
@@ -1,3 +0,0 @@
-require 'mkmf'
-create_makefile('probe')
-
diff --git a/ext/probe/probe.c b/ext/probe/probe.c
deleted file mode 100644
index e252b767b9..0000000000
--- a/ext/probe/probe.c
+++ /dev/null
@@ -1,47 +0,0 @@
-/**
- * probe.c - 
- *
- * $Author$
- *
- * Based on the patch for Ruby 1.8.6 by Joyent Inc.
- *
- * Copyright 2007 Joyent Inc.
- * Copyright 2009 Yuki Sonoda (Yugui).
- */
-#include "ruby/ruby.h"
-
-#define FIRE_WITH_SUFFIXED_MSG(probe_name, probe_data, suffix) \
-    if (TRACE_RUBY_PROBE_ENABLED()) { \
-        char *msg = ALLOCA_N(char, strlen(probe_name) + strlen("-" #suffix) ); \
-        sprintf(msg, "%s%s", probe_name, "-" #suffix); \
-        FIRE_RUBY_PROBE(msg, (char*)probe_data); \
-    }
-
-static VALUE
-probe_fire(int argc, VALUE *argv, VALUE klass)
-{
-    int args;
-    VALUE name, data, ret;
-    const char *probe_data;
-    char *probe_name;
-
-    args = rb_scan_args(argc, argv, "11", &name, &data);
-    probe_data = args == 2 ? StringValuePtr(data) : "";
-    probe_name = StringValuePtr(name);
-
-    if (rb_block_given_p()) {
-        FIRE_WITH_SUFFIXED_MSG(probe_name, probe_data, start);
-	ret = rb_yield(Qnil);
-        FIRE_WITH_SUFFIXED_MSG(probe_name, probe_data, end);
-    } else {
-	if (TRACE_RUBY_PROBE_ENABLED())
-	    FIRE_RUBY_PROBE(probe_name, (char*)probe_data);
-	ret = Qnil;
-    }
-    return ret;
-}
-
-void Init_probe()
-{
-    rb_define_global_function("fire_probe", probe_fire, -1);
-}
diff --git a/gc.c b/gc.c
index 3ccf10271a..40212204a3 100644
--- a/gc.c
+++ b/gc.c
@@ -460,7 +460,6 @@ ruby_memerror(void)
 	else {
 	    /* no ruby thread */
 	    fprintf(stderr, "[FATAL] failed to allocate memory\n");
-            if (UNLIKELY(TRACE_RAISE_ENABLED())) FIRE_RAISE_FATAL();
 	    exit(EXIT_FAILURE);
 	}
     }
@@ -473,7 +472,6 @@ rb_memerror(void)
     if (!nomem_error ||
 	(rb_thread_raised_p(th, RAISED_NOMEMORY) && rb_safe_level() < 4)) {
 	fprintf(stderr, "[FATAL] failed to allocate memory\n");
-        if (UNLIKELY(TRACE_RAISE_ENABLED())) FIRE_RAISE_FATAL();
 	exit(EXIT_FAILURE);
     }
     if (rb_thread_raised_p(th, RAISED_NOMEMORY)) {
@@ -606,7 +604,6 @@ negative_size_allocation_error(const char *msg)
 	}
 	else {
 	    fprintf(stderr, "[FATAL] %s\n", msg);
-            if (UNLIKELY(TRACE_RAISE_ENABLED())) FIRE_RAISE_FATAL();
 	    exit(EXIT_FAILURE);
 	}
     }
@@ -632,7 +629,6 @@ garbage_collect_with_gvl(rb_objspace_t *objspace)
 	else {
 	    /* no ruby thread */
 	    fprintf(stderr, "[FATAL] failed to allocate memory\n");
-            if (UNLIKELY(TRACE_RAISE_ENABLED())) FIRE_RAISE_FATAL();
 	    exit(EXIT_FAILURE);
 	}
     }
@@ -1977,8 +1973,6 @@ obj_free(rb_objspace_t *objspace, VALUE obj)
 	break;
     }
 
-    if (UNLIKELY(TRACE_OBJECT_FREE_ENABLED())) FIRE_OBJECT_FREE(rb_obj_id(obj));
-
     if (FL_TEST(obj, FL_EXIVAR)) {
 	rb_free_generic_ivar((VALUE)obj);
 	FL_UNSET(obj, FL_EXIVAR);
@@ -2159,7 +2153,6 @@ garbage_collect(rb_objspace_t *objspace)
     during_gc++;
     objspace->count++;
 
-    if (UNLIKELY(TRACE_GC_BEGIN_ENABLED())) FIRE_GC_BEGIN();
     GC_PROF_TIMER_START;
     GC_PROF_MARK_TIMER_START;
     SET_STACK_END;
@@ -2208,7 +2201,6 @@ garbage_collect(rb_objspace_t *objspace)
     GC_PROF_SWEEP_TIMER_STOP;
 
     GC_PROF_TIMER_STOP;
-    if (UNLIKELY(TRACE_GC_END_ENABLED())) FIRE_GC_END();
     if (GC_NOTIFY) printf("end garbage_collect()\n");
     return TRUE;
 }
diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index ebef0e9605..5318772b35 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -40,19 +40,10 @@ extern "C" {
 #endif
 
 #ifdef __GNUC__
-# define PRINTF_ARGS(decl, string_index, first_to_check) \
-   decl __attribute__((format(printf, string_index, first_to_check)))
-# if __GNUC__ >= 3
-#  define LIKELY(x)   (__builtin_expect((x), 1))
-#  define UNLIKELY(x) (__builtin_expect((x), 0))
-# else
-#  define LIKELY(x)   (x)
-#  define UNLIKELY(x) (x)
-# endif
+#define PRINTF_ARGS(decl, string_index, first_to_check) \
+  decl __attribute__((format(printf, string_index, first_to_check)))
 #else
-# define PRINTF_ARGS(decl, string_index, first_to_check) decl
-# define LIKELY(x)   (x)
-# define UNLIKELY(x) (x)
+#define PRINTF_ARGS(decl, string_index, first_to_check) decl
 #endif
 
 #ifdef HAVE_STDLIB_H
@@ -525,17 +516,12 @@ double rb_num2dbl(VALUE);
 VALUE rb_uint2big(VALUE);
 VALUE rb_int2big(SIGNED_VALUE);
 
-#include "ruby/trace.h"
-
 VALUE rb_newobj(void);
 #define NEWOBJ(obj,type) type *obj = (type*)rb_newobj()
 #define OBJSETUP(obj,c,t) do {\
     RBASIC(obj)->flags = (t);\
     RBASIC(obj)->klass = (c);\
     if (rb_safe_level() >= 3) FL_SET(obj, FL_TAINT | FL_UNTRUSTED);\
-    if (UNLIKELY(TRACE_OBJECT_CREATE_ENABLED())) { \
-        FIRE_OBJECT_CREATE((VALUE)(obj), rb_class2name((c)), rb_sourcefile(), rb_sourceline()); \
-    } \
 } while (0)
 #define CLONESETUP(clone,obj) do {\
     OBJSETUP(clone,rb_singleton_class_clone((VALUE)obj),RBASIC(obj)->flags);\
@@ -1339,7 +1325,6 @@ int ruby_native_thread_p(void);
 #define RUBY_EVENT_C_CALL    0x0020
 #define RUBY_EVENT_C_RETURN  0x0040
 #define RUBY_EVENT_RAISE     0x0080
-#define RUBY_EVENT_RESCUE    0x0100
 #define RUBY_EVENT_ALL       0xffff
 #define RUBY_EVENT_VM       0x10000
 #define RUBY_EVENT_SWITCH   0x20000
diff --git a/include/ruby/trace.h b/include/ruby/trace.h
deleted file mode 100644
index f45e9d5396..0000000000
--- a/include/ruby/trace.h
+++ /dev/null
@@ -1,105 +0,0 @@
-/**********************************************************************
-
-  trace.h -
-
-  $Author$
-
-  Copyright (C) 2009 Yuki Sonoda (Yugui)
-
-**********************************************************************/
-
-#ifndef RUBY_TRACE_H
-#define RUBY_TRACE_H
-
-#define RUBY_TRACING_MODEL_NONE 0
-#define RUBY_TRACING_MODEL_DTRACE 1
-
-#if RUBY_TRACING_MODEL == RUBY_TRACING_MODEL_NONE
-# define TRACE_METHOD_ENTRY_ENABLED() 0
-# define TRACE_METHOD_RETURN_ENABLED() 0
-# define TRACE_RAISE_ENABLED() 0
-# define TRACE_RESCUE_ENABLED() 0
-# define TRACE_LINE_ENABLED() 0
-# define TRACE_GC_BEGIN_ENABLED() 0
-# define TRACE_GC_END_ENABLED() 0
-# define TRACE_THREAD_INIT_ENABLED()  0
-# define TRACE_THREAD_TERM_ENABLED()  0
-# define TRACE_THREAD_LEAVE_ENABLED() 0
-# define TRACE_THREAD_ENTER_ENABLED() 0
-# define TRACE_OBJECT_CREATE_ENABLED() 0
-# define TRACE_OBJECT_FREE_ENABLED() 0
-# define TRACE_INSN_ENTRY_ENABLED() 0
-# define TRACE_INSN_RETURN_ENABLED() 0
-# define TRACE_RUBY_PROBE_ENABLED() 0
-
-# define FIRE_METHOD_ENTRY(receiver, classname, methodname, sourcefile, sourceline) ((void)0)
-# define FIRE_METHOD_RETURN(receiver, classname, methodname, sourcefile, sourceline) ((void)0)
-# define FIRE_RAISE(exception, classname, sourcename, sourceline) ((void)0)
-# define FIRE_RESCUE(exception, classname, sourcename, sourceline) ((void)0)
-# define FIRE_LINE(sourcename, sourceline) ((void)0)
-# define FIRE_GC_BEGIN() ((void)0)
-# define FIRE_GC_END() ((void)0)
-# define FIRE_THREAD_INIT(th, sourcefile, sourceline) ((void)0)
-# define FIRE_THREAD_TERM(th, sourcefile, sourceline) ((void)0)
-# define FIRE_THREAD_LEAVE(th, sourcefile, sourceline) ((void)0)
-# define FIRE_THREAD_ENTER(th, sourcefile, sourceline) ((void)0)
-# define FIRE_OBJECT_CREATE(obj, classname, sourcefile, sourceline) ((void)0)
-# define FIRE_OBJECT_FREE(obj) ((void)0)
-# define FIRE_INSN_ENTRY(insnname, operands, sourcename, sourceline) ((void)0)
-# define FIRE_INSN_RETURN(insnname, operands, sourcename, sourceline) ((void)0)
-# define FIRE_RUBY_PROBE(name, data) ((void)0)
-
-#elif RUBY_TRACING_MODEL == RUBY_TRACING_MODEL_DTRACE
-# include "ruby/trace_dtrace.h"
-# define TRACE_METHOD_ENTRY_ENABLED()  RUBY_METHOD_ENTRY_ENABLED()
-# define TRACE_METHOD_RETURN_ENABLED() RUBY_METHOD_RETURN_ENABLED()
-# define TRACE_RAISE_ENABLED()         RUBY_RAISE_ENABLED()
-# define TRACE_RESCUE_ENABLED()        RUBY_RESCUE_ENABLED()
-# define TRACE_LINE_ENABLED()          RUBY_LINE_ENABLED()
-# define TRACE_GC_BEGIN_ENABLED()      RUBY_GC_BEGIN_ENABLED()
-# define TRACE_GC_END_ENABLED()        RUBY_GC_END_ENABLED()
-# define TRACE_THREAD_INIT_ENABLED()  RUBY_THREAD_INIT_ENABLED()
-# define TRACE_THREAD_TERM_ENABLED()  RUBY_THREAD_TERM_ENABLED()
-# define TRACE_THREAD_LEAVE_ENABLED()  RUBY_THREAD_LEAVE_ENABLED()
-# define TRACE_THREAD_ENTER_ENABLED()  RUBY_THREAD_ENTER_ENABLED()
-# define TRACE_OBJECT_CREATE_ENABLED() RUBY_OBJECT_CREATE_ENABLED()
-# define TRACE_OBJECT_FREE_ENABLED()   RUBY_OBJECT_FREE_ENABLED()
-# define TRACE_INSN_ENTRY_ENABLED()    RUBY_INSN_ENTRY_ENABLED()
-# define TRACE_INSN_RETURN_ENABLED()   RUBY_INSN_RETURN_ENABLED()
-# define TRACE_RUBY_PROBE_ENABLED()    RUBY_RUBY_PROBE_ENABLED()
-
-# define FIRE_METHOD_ENTRY(receiver, classname, methodname, sourcefile, sourceline) \
-   RUBY_METHOD_ENTRY(receiver, classname, methodname, sourcefile, sourceline)
-# define FIRE_METHOD_RETURN(receiver, classname, methodname, sourcefile, sourceline) \
-   RUBY_METHOD_RETURN(receiver, classname, methodname, sourcefile, sourceline)
-# define FIRE_RAISE(exception, classname, sourcename, sourceline) \
-   RUBY_RAISE(exception, classname, sourcename, sourceline)
-# define FIRE_RESCUE(exception, classname, sourcename, sourceline) \
-   RUBY_RESCUE(exception, classname, sourcename, sourceline)
-# define FIRE_LINE(sourcename, sourceline) \
-   RUBY_LINE(sourcename, sourceline)
-# define FIRE_GC_BEGIN()     RUBY_GC_BEGIN()
-# define FIRE_GC_END()       RUBY_GC_END()
-# define FIRE_THREAD_INIT(th, sourcefile, sourceline) \
-   RUBY_THREAD_INIT(th, (char*)sourcefile, sourceline)
-# define FIRE_THREAD_TERM(th, sourcefile, sourceline) \
-   RUBY_THREAD_TERM(th, (char*)sourcefile, sourceline)
-# define FIRE_THREAD_LEAVE(th, sourcefile, sourceline) \
-   RUBY_THREAD_LEAVE(th, (char*)sourcefile, sourceline)
-# define FIRE_THREAD_ENTER(th, sourcefile, sourceline) \
-   RUBY_THREAD_ENTER(th, (char*)sourcefile, sourceline)
-# define FIRE_OBJECT_CREATE(obj, classname, sourcefile, sourceline) \
-   RUBY_OBJECT_CREATE(obj, (char*)classname, (char*)sourcefile, sourceline)
-# define FIRE_OBJECT_FREE(obj) \
-   RUBY_OBJECT_FREE(obj)
-# define FIRE_INSN_ENTRY(insnname, operands, sourcename, sourceline) \
-   RUBY_INSN_ENTRY(insnname, operands, sourcename, sourceline)
-# define FIRE_INSN_RETURN(insnname, operands, sourcename, sourceline) \
-   RUBY_INSN_RETURN(insnname, operands, sourcename, sourceline)
-# define FIRE_RUBY_PROBE(name, data) \
-   RUBY_RUBY_PROBE(name, data)
-#endif
-
-#define FIRE_RAISE_FATAL() FIRE_RAISE(0, (char*)"fatal", (char*)"<unknown>", 0)
-
-#endif
diff --git a/insns.def b/insns.def
index 869d7564d8..5f789bd441 100644
--- a/insns.def
+++ b/insns.def
@@ -859,30 +859,6 @@ trace
     rb_event_flag_t flag = (rb_event_flag_t)nf;
 
     EXEC_EVENT_HOOK(th, flag, GET_SELF(), 0, 0 /* TODO: id, klass */);
-    if (UNLIKELY(TRACE_METHOD_ENTRY_ENABLED()
-                | TRACE_METHOD_RETURN_ENABLED()
-                | TRACE_LINE_ENABLED()
-                | TRACE_RESCUE_ENABLED())) {
-	if (UNLIKELY(TRACE_METHOD_ENTRY_ENABLED()) && (flag & RUBY_EVENT_CALL) ) {
-	    VALUE self = GET_SELF(), klass;
-	    ID id;
-	    rb_thread_method_id_and_class(GET_THREAD(), &id, &klass);
-	    FIRE_METHOD_ENTRY(self, (char*)rb_class2name(klass), (char*)rb_id2name(id), (char*)rb_sourcefile(), rb_sourceline());
-	}
-	if (UNLIKELY(TRACE_METHOD_RETURN_ENABLED()) && (flag & RUBY_EVENT_RETURN) ) {
-	    VALUE self = GET_SELF(), klass;
-	    ID id;
-	    rb_thread_method_id_and_class(GET_THREAD(), &id, &klass);
-	    FIRE_METHOD_RETURN(self, (char*)rb_class2name(klass), (char*)rb_id2name(id), (char*)rb_sourcefile(), rb_sourceline());
-	}
-	if (UNLIKELY(TRACE_RESCUE_ENABLED()) && (flag & RUBY_EVENT_RESCUE) ) {
-            VALUE ex = GET_DFP()[-2];
-	    FIRE_RESCUE(ex, (char*)rb_class2name(CLASS_OF(ex)), (char*)rb_sourcefile(), rb_sourceline());
-	}
-	if (UNLIKELY(TRACE_LINE_ENABLED()) && (flag & RUBY_EVENT_LINE) ) {
-	    FIRE_LINE((char*)rb_sourcefile(), rb_sourceline());
-	}
-    }
 }
 
 /**********************************************************/
diff --git a/iseq.c b/iseq.c
index c247b8c90d..7a59fce049 100644
--- a/iseq.c
+++ b/iseq.c
@@ -1473,27 +1473,6 @@ rb_iseq_build_for_ruby2cext(
     return iseqval;
 }
 
-const char *
-rb_vm_insn_name(int insn)
-{
-    if (insn < VM_INSTRUCTION_SIZE) {
-        return insn_name(insn);
-    } else {
-        return 0;
-    }
-}
-
-int
-rb_vm_insn_len(int insn)
-{
-    if (insn < VM_INSTRUCTION_SIZE) {
-        return insn_len(insn);
-    } else {
-        return 0;
-    }
-}
-
-
 void
 Init_ISeq(void)
 {
diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index 0ad63d61e3..895bca0bee 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -69,8 +69,6 @@ $solaris = /solaris/ =~ RUBY_PLATFORM
 $universal = /universal/ =~ RUBY_PLATFORM
 $dest_prefix_pattern = (File::PATH_SEPARATOR == ';' ? /\A([[:alpha:]]:)?/ : /\A/)
 
-$dtrace_postprocess = (CONFIG['DTRACE_OBJ'] and /^\s*$/ !~ CONFIG['DTRACE_OBJ'])
-
 # :stopdoc:
 
 def config_string(key, config = CONFIG)
@@ -1452,7 +1450,6 @@ VPATH = #{vpath.join(CONFIG['PATH_SEPARATOR'])}
   mk << %{
 CC = #{CONFIG['CC']}
 CXX = #{CONFIG['CXX']}
-DTRACE = #{CONFIG['DTRACE']}
 LIBRUBY = #{CONFIG['LIBRUBY']}
 LIBRUBY_A = #{CONFIG['LIBRUBY_A']}
 LIBRUBYARG_SHARED = #$LIBRUBYARG_SHARED
@@ -1722,7 +1719,6 @@ LOCAL_LIBS = #{$LOCAL_LIBS}
 LIBS = #{$LIBRUBYARG} #{$libs} #{$LIBS}
 SRCS = #{srcs.collect(&File.method(:basename)).join(' ')}
 OBJS = #{$objs.join(" ")}
-DTRACE_OBJ = #{$dtrace_postprocess ? "$(TARGET)_dtrace.#{$OBJEXT}" : ''}
 TARGET = #{target}
 DLLIB = #{dllib}
 EXTSTATIC = #{$static || ""}
@@ -1743,12 +1739,6 @@ static: $(STATIC_LIB)#{$extout ? " install-rb" : ""}
 .PHONY: clean clean-so clean-rb
 "
   mfile.print CLEANINGS
-
-  if $dtrace_postprocess 
-    mfile.print "$(DTRACE_OBJ): $(OBJS)\n"
-    mfile.print "\t$(DTRACE) -G -o $@ -s $(arch_hdrdir)/ruby/dtrace.d $(OBJS)\n"
-  end
-
   fsep = config_string('BUILD_FILE_SEPARATOR') {|s| s unless s == "/"}
   if fsep
     sep = ":/=#{fsep}"
@@ -1851,7 +1841,7 @@ site-install-rb: install-rb
   mfile.print "$(RUBYARCHDIR)/" if $extout
   mfile.print "$(DLLIB): "
   mfile.print "$(DEFFILE) " if makedef
-  mfile.print "$(OBJS) $(DTRACE_OBJ) Makefile\n"
+  mfile.print "$(OBJS) Makefile\n"
   mfile.print "\t@-$(RM) $(@#{sep})\n"
   mfile.print "\t@-$(MAKEDIRS) $(@D)\n" if $extout
   link_so = LINK_SO.gsub(/^/, "\t")
@@ -1860,8 +1850,8 @@ site-install-rb: install-rb
   end
   mfile.print link_so, "\n\n"
   unless $static.nil?
-    mfile.print "$(STATIC_LIB): $(OBJS) $(DTRACE_OBJ)\n\t@-$(RM) $(@#{sep})\n\t"
-    mfile.print "$(AR) #{config_string('ARFLAGS') || 'cru '}$@ $(OBJS) $(DTRACE_OBJ)"
+    mfile.print "$(STATIC_LIB): $(OBJS)\n\t@-$(RM) $(@#{sep})\n\t"
+    mfile.print "$(AR) #{config_string('ARFLAGS') || 'cru '}$@ $(OBJS)"
     config_string('RANLIB') do |ranlib|
       mfile.print "\n\t@-#{ranlib} $(DLLIB) 2> /dev/null || true"
     end
@@ -1882,7 +1872,6 @@ site-install-rb: install-rb
     end
     headers << $config_h
     headers << '$(RUBY_EXTCONF_H)' if $extconf_h
-    headers << '$(arch_hdrdir)/ruby/dtrace.d' if $dtrace_postprocess
     mfile.print "$(OBJS): ", headers.join(' '), "\n"
   end
 
@@ -2015,9 +2004,9 @@ TRY_LINK = config_string('TRY_LINK') ||
   "$(CFLAGS) $(src) $(LIBPATH) $(LDFLAGS) $(ARCH_FLAG) $(LOCAL_LIBS) $(LIBS)"
 LINK_SO = config_string('LINK_SO') ||
   if CONFIG["DLEXT"] == $OBJEXT
-    "ld $(DLDFLAGS) -r -o $@ $(OBJS) $(DTRACE_OBJ)\n"
+    "ld $(DLDFLAGS) -r -o $@ $(OBJS)\n"
   else
-    "$(LDSHARED) #{OUTFLAG}$@ $(OBJS) $(DTRACE_OBJ) " \
+    "$(LDSHARED) #{OUTFLAG}$@ $(OBJS) " \
     "$(LIBPATH) $(DLDFLAGS) $(LOCAL_LIBS) $(LIBS)"
   end
 LIBPATHFLAG = config_string('LIBPATHFLAG') || ' -L"%s"'
diff --git a/thread.c b/thread.c
index bcb7be5214..0ba41c7679 100644
--- a/thread.c
+++ b/thread.c
@@ -376,8 +376,6 @@ thread_cleanup_func(void *th_ptr)
 {
     rb_thread_t *th = th_ptr;
 
-    if (UNLIKELY(TRACE_THREAD_TERM_ENABLED())) FIRE_THREAD_TERM(th->self, rb_sourcefile(), rb_sourceline());
-
     /* unlock all locking mutexes */
     if (th->keeping_mutexes) {
 	rb_mutex_unlock_all(th->keeping_mutexes, th);
@@ -429,16 +427,10 @@ thread_start_func_2(rb_thread_t *th, VALUE *stack_start, VALUE *register_stack_s
 		    th->errinfo = Qnil;
 		    th->local_lfp = proc->block.lfp;
 		    th->local_svar = Qnil;
-		    if (UNLIKELY(TRACE_THREAD_ENTER_ENABLED())) {
-			VALUE filename = proc->block.iseq->filename;
-			int lineno = proc->block.iseq->line_no;
-			FIRE_THREAD_ENTER(th->self, (TYPE(filename) == T_STRING ? RSTRING_PTR(filename) : 0), lineno);
-		    }
 		    th->value = rb_vm_invoke_proc(th, proc, proc->block.self,
 						  (int)RARRAY_LEN(args), RARRAY_PTR(args), 0);
 		}
 		else {
-		    if (UNLIKELY(TRACE_THREAD_ENTER_ENABLED())) FIRE_THREAD_ENTER(th->self, 0, 0);
 		    th->value = (*th->first_func)((void *)args);
 		}
 	    });
@@ -469,7 +461,6 @@ thread_start_func_2(rb_thread_t *th, VALUE *stack_start, VALUE *register_stack_s
 
 	th->status = THREAD_KILLED;
 	thread_debug("thread end: %p\n", (void *)th);
-	if (UNLIKELY(TRACE_THREAD_LEAVE_ENABLED())) FIRE_THREAD_LEAVE(th->self, 0, 0);
 
 	main_th = th->vm->main_thread;
 	if (th != main_th) {
@@ -542,7 +533,6 @@ thread_create_core(VALUE thval, VALUE args, VALUE (*fn)(ANYARGS))
     native_mutex_initialize(&th->interrupt_lock);
     /* kick thread */
     st_insert(th->vm->living_threads, thval, (st_data_t) th->thread_id);
-    if (UNLIKELY(TRACE_THREAD_INIT_ENABLED())) FIRE_THREAD_INIT(th->self, rb_sourcefile(), rb_sourceline());
     err = native_thread_create(th);
     if (err) {
 	st_delete_wrap(th->vm->living_threads, th->self);
@@ -992,7 +982,6 @@ rb_thread_schedule_rec(int sched_depth)
 	rb_thread_t *th = GET_THREAD();
 
 	thread_debug("rb_thread_schedule/switch start\n");
-        if (UNLIKELY(TRACE_THREAD_LEAVE_ENABLED())) FIRE_THREAD_LEAVE(th->self, rb_sourcefile(), rb_sourceline());
 
 	RB_GC_SAVE_MACHINE_CONTEXT(th);
 	native_mutex_unlock(&th->vm->global_vm_lock);
@@ -1003,7 +992,6 @@ rb_thread_schedule_rec(int sched_depth)
 
 	rb_thread_set_current(th);
 	thread_debug("rb_thread_schedule/switch done\n");
-        if (UNLIKELY(TRACE_THREAD_ENTER_ENABLED())) FIRE_THREAD_ENTER(th->self, rb_sourcefile(), rb_sourceline());
 
         if (!sched_depth && UNLIKELY(GET_THREAD()->interrupt_flag)) {
             rb_threadptr_execute_interrupts_rec(GET_THREAD(), sched_depth+1);
diff --git a/thread_pthread.c b/thread_pthread.c
index 3335a45839..af0b28644a 100644
--- a/thread_pthread.c
+++ b/thread_pthread.c
@@ -694,7 +694,6 @@ add_signal_thread_list(rb_thread_t *th)
 
 	    if (list == 0) {
 		fprintf(stderr, "[FATAL] failed to allocate memory\n");
-                if (UNLIKELY(TRACE_RAISE_ENABLED())) FIRE_RAISE_FATAL();
 		exit(1);
 	    }
 
@@ -806,7 +805,6 @@ rb_thread_create_timer_thread(void)
 	if (err != 0) {
 	    native_mutex_unlock(&timer_thread_lock);
 	    fprintf(stderr, "[FATAL] Failed to create timer thread (errno: %d)\n", err);
-            if (UNLIKELY(TRACE_RAISE_ENABLED())) FIRE_RAISE_FATAL();
 	    exit(EXIT_FAILURE);
 	}
 	native_cond_wait(&timer_thread_cond, &timer_thread_lock);
diff --git a/tool/rbinstall.rb b/tool/rbinstall.rb
index 55920a6d17..cf5827e6e2 100755
--- a/tool/rbinstall.rb
+++ b/tool/rbinstall.rb
@@ -346,7 +346,7 @@ install?(:ext, :arch, :'ext-arch') do
 end
 install?(:ext, :arch, :'ext-arch') do
   prepare "extension headers", archhdrdir
-  install_recursive("#{$extout}/include/#{CONFIG['arch']}", archhdrdir, :glob => "*.[dh]", :mode => $data_mode)
+  install_recursive("#{$extout}/include/#{CONFIG['arch']}", archhdrdir, :glob => "*.h", :mode => $data_mode)
 end
 install?(:ext, :comm, :'ext-comm') do
   prepare "extension scripts", rubylibdir
diff --git a/variable.c b/variable.c
index 722c021c59..62256a049e 100644
--- a/variable.c
+++ b/variable.c
@@ -313,27 +313,6 @@ rb_class2name(VALUE klass)
     return RSTRING_PTR(rb_class_name(klass));
 }
 
-/*!
- * \internal
- * Same as rb_class2name but safe if during GC
- *
- * \post the returned pointer points a string. not NULL.
- */
-const char *
-rb_class2name_without_alloc(VALUE klass)
-{
-    if (RCLASS_IV_TBL(klass)) {
-	st_data_t n;
-	if (st_lookup(RCLASS_IV_TBL(klass), (st_data_t)classpath, &n) ||
-	    st_lookup(RCLASS_IV_TBL(klass), (st_data_t)classid, &n) ||
-	    st_lookup(RCLASS_IV_TBL(klass), (st_data_t)tmp_classpath, &n)) {
-	    if (TYPE(n) != T_STRING) rb_bug("class path is not set properly");
-	    return RSTRING_PTR(n);
-	}
-    }
-    return "(anonymous)";
-}
-
 const char *
 rb_obj_classname(VALUE obj)
 {
diff --git a/vm.c b/vm.c
index 9f6fc124b9..e522c9f300 100644
--- a/vm.c
+++ b/vm.c
@@ -2072,7 +2072,6 @@ Init_BareVM(void)
     rb_thread_t * th = malloc(sizeof(*th));
     if (!vm || !th) {
 	fprintf(stderr, "[FATAL] failed to allocate memory\n");
-        if (UNLIKELY(TRACE_RAISE_ENABLED())) FIRE_RAISE_FATAL();
 	exit(EXIT_FAILURE);
     }
     MEMZERO(th, rb_thread_t, 1);
diff --git a/vm_core.h b/vm_core.h
index 0dd93f3332..b9b584ad69 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -97,6 +97,15 @@
 #endif /* OPT_STACK_CACHING */
 #endif /* OPT_CALL_THREADED_CODE */
 
+/* likely */
+#if __GNUC__ >= 3
+#define LIKELY(x)   (__builtin_expect((x), 1))
+#define UNLIKELY(x) (__builtin_expect((x), 0))
+#else /* __GNUC__ >= 3 */
+#define LIKELY(x)   (x)
+#define UNLIKELY(x) (x)
+#endif /* __GNUC__ >= 3 */
+
 typedef unsigned long rb_num_t;
 
 /* iseq data type */
diff --git a/vm_exec.h b/vm_exec.h
index 0a72f17854..9ae81794bd 100644
--- a/vm_exec.h
+++ b/vm_exec.h
@@ -52,39 +52,8 @@ typedef rb_iseq_t *ISEQ;
 #else
 
 #define debugs
-extern const char *rb_vm_insn_name(int);
-#define DEBUG_ENTER_INSN(insn) \
-    do { \
-	if (UNLIKELY(TRACE_INSN_ENTRY_ENABLED())) { \
-	    rb_control_frame_t *cfp = GET_CFP(); \
-	    rb_iseq_t *iseq = cfp->iseq; \
-	    if (iseq != NULL && VM_FRAME_TYPE(cfp) != VM_FRAME_MAGIC_FINISH) { \
-		VALUE *seq = iseq->iseq; \
-		int pc = cfp->pc - iseq->iseq_encoded; \
-		FIRE_INSN_ENTRY((char *)rb_vm_insn_name(seq[pc]), \
-                        seq+1, \
-			(char *)rb_sourcefile(), \
-			rb_sourceline()); \
-	    } \
-	} \
-    } \
-    while (0)
-#define DEBUG_END_INSN() \
-    do { \
-	if (UNLIKELY(TRACE_INSN_RETURN_ENABLED())) { \
-	    rb_control_frame_t *cfp = GET_CFP(); \
-	    rb_iseq_t *iseq = cfp->iseq; \
-	    if (iseq != NULL && VM_FRAME_TYPE(cfp) != VM_FRAME_MAGIC_FINISH) { \
-		VALUE *seq = iseq->iseq; \
-		int pc = cfp->pc - iseq->iseq_encoded; \
-		FIRE_INSN_RETURN((char *)rb_vm_insn_name(seq[pc]), \
-                        seq+1, \
-			(char *)rb_sourcefile(), \
-			rb_sourceline()); \
-	    } \
-	} \
-    } \
-    while (0)
+#define DEBUG_ENTER_INSN(insn)
+#define DEBUG_END_INSN()
 #endif
 
 #define throwdebug if(0)printf
diff --git a/win32/Makefile.sub b/win32/Makefile.sub
index fe7f5fae52..a27cfba707 100644
--- a/win32/Makefile.sub
+++ b/win32/Makefile.sub
@@ -288,7 +288,6 @@ LIBRUBY_SO    = $(RUBY_SO_NAME).dll
 LIBRUBY       = $(RUBY_SO_NAME).lib
 LIBRUBYARG    = $(LIBRUBY)
 THREAD_MODEL  = win32
-TRACING_MODEL = none
 
 !if $(CROSS_COMPILING)
 PREP          = fake.rb