lib: Remove dtrace/systemtap probes

These were added in libguestfs 1.14, but never really used.  Only a
handful of probes were available.  When I was benchmarking libguestfs
in 2016 I didn't even use these probes because better/simpler
techniques were available.

docs/guestfs-building.pod

@@ -218,10 +218,6 @@ eg. F</etc/libguestfs-tools.conf>.
 Optional.  Used by the L<libvirt backend|guestfs(3)/BACKEND> to
 securely confine the appliance (sVirt).
 
-=item systemtap
-
-Optional.  For userspace probes.
-
 =item readline
 
 Optional.  For nicer command line editing in L<guestfish(1)>.

docs/guestfs-performance.pod

@@ -434,72 +434,6 @@ timings:
 
 The timestamps are seconds (incrementally since the previous line).
 
-=head2 Detailed timings using SystemTap
-
-You can use SystemTap (L<stap(1)>) to get detailed timings from
-libguestfs programs.
-
-Save the following script as F<time.stap>:
-
- global last;
- 
- function display_time () {
-       now = gettimeofday_us ();
-       delta = 0;
-       if (last > 0)
-             delta = now - last;
-       last = now;
- 
-       printf ("%d (+%d):", now, delta);
- }
- 
- probe begin {
-       last = 0;
-       printf ("ready\n");
- }
- 
- /* Display all calls to static markers. */
- probe process("/usr/lib*/libguestfs.so.0")
-           .provider("guestfs").mark("*") ? {
-       display_time();
-       printf ("\t%s %s\n", $$name, $$parms);
- }
- 
- /* Display all calls to guestfs_* functions. */
- probe process("/usr/lib*/libguestfs.so.0")
-           .function("guestfs_[a-z]*") ? {
-       display_time();
-       printf ("\t%s %s\n", probefunc(), $$parms);
- }
-
-Run it as root in one window:
-
- # stap time.stap
- ready
-
-It prints "ready" when SystemTap has loaded the program.  Run your
-libguestfs program, guestfish or a virt tool in another window.  For
-example:
-
- $ guestfish -a /dev/null run
-
-In the stap window you will see a large amount of output, with the
-time taken for each step shown (microseconds in parenthesis).  For
-example:
-
- xxxx (+0):	guestfs_create 
- xxxx (+29):	guestfs_set_pgroup g=0x17a9de0 pgroup=0x1
- xxxx (+9):	guestfs_add_drive_opts_argv g=0x17a9de0 [...]
- xxxx (+8):	guestfs_int_safe_strdup g=0x17a9de0 str=0x7f8a153bed5d
- xxxx (+19):	guestfs_int_safe_malloc g=0x17a9de0 nbytes=0x38
- xxxx (+5):	guestfs_int_safe_strdup g=0x17a9de0 str=0x17a9f60
- xxxx (+10):	guestfs_launch g=0x17a9de0
- xxxx (+4):	launch_start 
- [etc]
-
-You will need to consult, and even modify, the source to libguestfs to
-fully understand the output.
-
 =head2 Detailed debugging using gdb
 
 You can attach to the appliance BIOS/kernel using gdb.  If you know

lib/guestfs-internal.h

@@ -63,26 +63,6 @@ typedef struct hash_table Hash_table;
 #endif
 #endif
 
-#if ENABLE_PROBES
-#include <sys/sdt.h>
-/* NB: The 'name' parameter is a literal identifier, NOT a string! */
-#define TRACE0(name) DTRACE_PROBE(guestfs, name)
-#define TRACE1(name, arg1) \
-  DTRACE_PROBE(guestfs, name, (arg1))
-#define TRACE2(name, arg1, arg2) \
-  DTRACE_PROBE(guestfs, name, (arg1), (arg2))
-#define TRACE3(name, arg1, arg2, arg3) \
-  DTRACE_PROBE(guestfs, name, (arg1), (arg2), (arg3))
-#define TRACE4(name, arg1, arg2, arg3, arg4) \
-  DTRACE_PROBE(guestfs, name, (arg1), (arg2), (arg3), (arg4))
-#else /* !ENABLE_PROBES */
-#define TRACE0(name)
-#define TRACE1(name, arg1)
-#define TRACE2(name, arg1, arg2)
-#define TRACE3(name, arg1, arg2, arg3)
-#define TRACE4(name, arg1, arg2, arg3, arg4)
-#endif
-
 /* https://stackoverflow.com/a/1597129 */
 #define XXUNIQUE_VAR(name, line) name ## line
 #define XUNIQUE_VAR(name, line) XXUNIQUE_VAR (name, line)

lib/guestfs.pod

@@ -2879,77 +2879,6 @@ are being deleted, but other manipulations of keys within the loop
 might not terminate unless you also maintain an indication of which
 keys have been visited.
 
-=head1 SYSTEMTAP
-
-The libguestfs C library can be probed using systemtap or DTrace.
-This is true of any library, not just libguestfs.  However libguestfs
-also contains static markers to help in probing internal operations.
-
-You can list all the static markers by doing:
-
- stap -l 'process("/usr/lib*/libguestfs.so.0")
-              .provider("guestfs").mark("*")'
-
-B<Note:> These static markers are I<not> part of the stable API and
-may change in future versions.
-
-=head2 SYSTEMTAP SCRIPT EXAMPLE
-
-This script contains examples of displaying both the static markers
-and some ordinary C entry points:
-
- global last;
- 
- function display_time () {
-       now = gettimeofday_us ();
-       delta = 0;
-       if (last > 0)
-             delta = now - last;
-       last = now;
- 
-       printf ("%d (+%d):", now, delta);
- }
- 
- probe begin {
-       last = 0;
-       printf ("ready\n");
- }
- 
- /* Display all calls to static markers. */
- probe process("/usr/lib*/libguestfs.so.0")
-           .provider("guestfs").mark("*") ? {
-       display_time();
-       printf ("\t%s %s\n", $$name, $$parms);
- }
- 
- /* Display all calls to guestfs_mkfs* functions. */
- probe process("/usr/lib*/libguestfs.so.0")
-           .function("guestfs_mkfs*") ? {
-       display_time();
-       printf ("\t%s %s\n", probefunc(), $$parms);
- }
-
-The script above can be saved to F<test.stap> and run using the
-L<stap(1)> program.  Note that you either have to be root, or you have
-to add yourself to several special stap groups.  Consult the systemtap
-documentation for more information.
-
- # stap /tmp/test.stap
- ready
-
-In another terminal, run a guestfish command such as this:
-
- guestfish -N fs
-
-In the first terminal, stap trace output similar to this is shown:
-
- 1318248056692655 (+0):	launch_start
- 1318248056692850 (+195):       launch_build_appliance_start
- 1318248056818285 (+125435):    launch_build_appliance_end
- 1318248056838059 (+19774):     launch_run_qemu
- 1318248061071167 (+4233108):   launch_end
- 1318248061280324 (+209157):    guestfs_mkfs g=0x1024ab0 fstype=0x46116f device=0x1024e60
-
 =head1 LIBGUESTFS VERSION NUMBERS
 
 Since April 2010, libguestfs has started to make separate development

lib/launch-direct.c

@@ -365,15 +365,11 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
 
   guestfs_int_launch_send_progress (g, 0);
 
-  TRACE0 (launch_build_appliance_start);
-
   /* Locate and/or build the appliance. */
   if (guestfs_int_build_appliance (g, &kernel, &initrd, &appliance) == -1)
     return -1;
   has_appliance_drive = appliance != NULL;
 
-  TRACE0 (launch_build_appliance_end);
-
   guestfs_int_launch_send_progress (g, 3);
 
   debug (g, "begin testing qemu features");
@@ -760,8 +756,6 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
     setenv ("LC_ALL", "C", 1);
     setenv ("QEMU_AUDIO_DRV", "none", 1); /* Prevents qemu opening /dev/dsp */
 
-    TRACE0 (launch_run_qemu);
-
     execv (g->hv, argv);        /* Run qemu. */
     perror (g->hv);
     _exit (EXIT_FAILURE);
@@ -902,8 +896,6 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
     goto cleanup1;
   }
 
-  TRACE0 (launch_end);
-
   guestfs_int_launch_send_progress (g, 12);
 
   if (has_appliance_drive)

lib/launch-libvirt.c

@@ -362,7 +362,6 @@ launch_libvirt (guestfs_h *g, void *datav, const char *libvirt_uri)
   }
 
   guestfs_int_launch_send_progress (g, 0);
-  TRACE0 (launch_libvirt_start);
 
   /* Create a random name for the guest. */
   memcpy (data->name, "guestfs-", 8);
@@ -481,8 +480,6 @@ launch_libvirt (guestfs_h *g, void *datav, const char *libvirt_uri)
   guestfs_pop_error_handler (g);
 
   /* Locate and/or build the appliance. */
-  TRACE0 (launch_build_libvirt_appliance_start);
-
   debug (g, "build appliance");
 
   if (guestfs_int_build_appliance (g, &params.kernel, &params.initrd,
@@ -490,7 +487,6 @@ launch_libvirt (guestfs_h *g, void *datav, const char *libvirt_uri)
     goto cleanup;
 
   guestfs_int_launch_send_progress (g, 3);
-  TRACE0 (launch_build_libvirt_appliance_end);
 
   /* Note that appliance can be NULL if using the old-style appliance. */
   if (params.appliance) {
@@ -503,8 +499,6 @@ launch_libvirt (guestfs_h *g, void *datav, const char *libvirt_uri)
       goto cleanup;
   }
 
-  TRACE0 (launch_build_libvirt_qcow2_overlay_end);
-
   /* Using virtio-serial, we need to create a local Unix domain socket
    * for qemu to connect to.
    */
@@ -717,8 +711,6 @@ launch_libvirt (guestfs_h *g, void *datav, const char *libvirt_uri)
   if (params.appliance)
     guestfs_int_add_dummy_appliance_drive (g);
 
-  TRACE0 (launch_libvirt_end);
-
   guestfs_int_launch_send_progress (g, 12);
 
   data->conn = conn;

lib/launch.c

@@ -79,7 +79,6 @@ guestfs_impl_launch (guestfs_h *g)
 
   /* Start the clock ... */
   gettimeofday (&g->launch_t, NULL);
-  TRACE0 (launch_start);
 
   /* Make the temporary directory. */
   if (guestfs_int_lazy_make_tmpdir (g) == -1)

m4/guestfs-libraries.m4

@@ -225,21 +225,6 @@ if test "x$have_libselinux" = "xyes"; then
 fi
 AC_SUBST([SELINUX_LIBS])
 
-dnl Check for systemtap/DTrace userspace probes (optional).
-dnl Since the probe points break under clang, allow this to be disabled.
-AC_ARG_ENABLE([probes],
-    AS_HELP_STRING([--disable-probes], [disable systemtap/DTrace userspace probes]),
-    [],
-    [enable_probes=yes])
-AS_IF([test "x$enable_probes" != "xno"],[
-    dnl http://sourceware.org/systemtap/wiki/AddingUserSpaceProbingToApps
-    AC_CHECK_HEADERS([sys/sdt.h])
-    dnl AC_CHECK_PROG([DTRACE],[dtrace],[dtrace],[no])
-    AS_IF([test "x$ac_cv_header_sys_sdt_h" = "xyes"],[
-        AC_DEFINE([ENABLE_PROBES],[1],[Enable systemtap/DTrace userspace probes.])
-    ])
-])
-
 dnl Enable packet dumps when in verbose mode.  This generates lots
 dnl of debug info, only useful for people debugging the RPC mechanism.
 AC_ARG_ENABLE([packet-dump],[