sysprof/0017-libsysprof-add-SysprofUserSampler-for-live-unwinding.patch
Christian Hergert 857a3982f5 Update to 47.2
Resolves: RHEL-69379
2024-11-27 09:59:15 -08:00

695 lines
22 KiB
Diff

From bbf467f63a4e7df9076a6ec98bb264c83463dcc3 Mon Sep 17 00:00:00 2001
From: Christian Hergert <chergert@redhat.com>
Date: Sun, 3 Nov 2024 10:53:29 -0800
Subject: [PATCH 17/33] libsysprof: add SysprofUserSampler for live unwinding
This instrument triggers the live unwinder in sysprofd to capture a
pre-configured amount of stack contents and CPU registers. You can use
this instead of SysprofSampler in cases where you do not have frame-
pointers but want a useful trace.
It does have a moderate amount of CPU overhead compared to just relying
on frame-pointers so keep that in mind. Generally useful on platforms
that do not have frame pointers such as CentOS.
---
src/libsysprof/meson.build | 7 +
src/libsysprof/sysprof-user-sampler.c | 570 ++++++++++++++++++++++++++
src/libsysprof/sysprof-user-sampler.h | 43 ++
src/libsysprof/sysprof.h | 1 +
4 files changed, 621 insertions(+)
create mode 100644 src/libsysprof/sysprof-user-sampler.c
create mode 100644 src/libsysprof/sysprof-user-sampler.h
diff --git a/src/libsysprof/meson.build b/src/libsysprof/meson.build
index f3fa0850..e49c3a37 100644
--- a/src/libsysprof/meson.build
+++ b/src/libsysprof/meson.build
@@ -63,6 +63,7 @@ libsysprof_public_sources = [
'sysprof-time-span.c',
'sysprof-tracefd-consumer.c',
'sysprof-tracer.c',
+ 'sysprof-user-sampler.c',
]
libsysprof_public_headers = [
@@ -130,6 +131,7 @@ libsysprof_public_headers = [
'sysprof-time-span.h',
'sysprof-tracefd-consumer.h',
'sysprof-tracer.h',
+ 'sysprof-user-sampler.h',
]
libsysprof_private_sources = [
@@ -154,6 +156,11 @@ libsysprof_private_sources = [
'sysprof-strings.c',
'sysprof-symbol-cache.c',
'timsort/gtktimsort.c',
+
+ gnome.gdbus_codegen('ipc-unwinder',
+ sources: '../sysprofd/org.gnome.Sysprof3.Unwinder.xml',
+ interface_prefix: 'org.gnome.Sysprof3.',
+ namespace: 'Ipc'),
]
if debuginfod_dep.found()
diff --git a/src/libsysprof/sysprof-user-sampler.c b/src/libsysprof/sysprof-user-sampler.c
new file mode 100644
index 00000000..0e3afeae
--- /dev/null
+++ b/src/libsysprof/sysprof-user-sampler.c
@@ -0,0 +1,570 @@
+/* sysprof-user-sampler.c
+ *
+ * Copyright 2023 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "config.h"
+
+#include <sys/ioctl.h>
+#include <sys/eventfd.h>
+
+#include <asm/perf_regs.h>
+
+#include <glib/gstdio.h>
+
+#include "sysprof-instrument-private.h"
+#include "sysprof-perf-event-stream-private.h"
+#include "sysprof-recording-private.h"
+#include "sysprof-user-sampler.h"
+#include "sysprof-muxer-source.h"
+
+#include "ipc-unwinder.h"
+
+/* The following was provided to Sysprof by Serhei Makarov as part
+ * of the eu-stacktrace prototype work.
+ */
+#ifdef _ASM_X86_PERF_REGS_H
+/* #define SYSPROF_ARCH_PREFERRED_REGS PERF_REG_EXTENDED_MASK -- error on x86_64 due to including segment regs*/
+#define REG(R) (1ULL << PERF_REG_X86_ ## R)
+#define DWARF_NEEDED_REGS (/* no FLAGS */ REG(IP) | REG(SP) | REG(AX) | REG(CX) | REG(DX) | REG(BX) | REG(SI) | REG(DI) | REG(SP) | REG(BP) | /* no segment regs */ REG(R8) | REG(R9) | REG(R10) | REG(R11) | REG(R12) | REG(R13) | REG(R14) | REG(R15))
+/* XXX register ordering is defined in linux arch/x86/include/uapi/asm/perf_regs.h;
+ see code in tools/perf/util/intel-pt.c intel_pt_add_gp_regs()
+ and note how registers are added in the same order as the perf_regs.h enum */
+#define SYSPROF_ARCH_PREFERRED_REGS DWARF_NEEDED_REGS
+/* TODO: add other architectures, imitating the linux tools/perf tree */
+#else
+# define SYSPROF_ARCH_PREFERRED_REGS PERF_REG_EXTENDED_MASK
+#endif /* _ASM_{arch}_PERF_REGS_H */
+
+#define N_WAKEUP_EVENTS 149
+
+struct _SysprofUserSampler
+{
+ SysprofInstrument parent_instance;
+ GArray *perf_fds;
+ int capture_fd;
+ int event_fd;
+ guint stack_size;
+};
+
+struct _SysprofUserSamplerClass
+{
+ SysprofInstrumentClass parent_class;
+};
+
+G_DEFINE_FINAL_TYPE (SysprofUserSampler, sysprof_user_sampler, SYSPROF_TYPE_INSTRUMENT)
+
+static void
+close_fd (gpointer data)
+{
+ int *fdp = data;
+
+ if (*fdp != -1)
+ {
+ close (*fdp);
+ *fdp = -1;
+ }
+}
+
+static void
+sysprof_user_sampler_ioctl (SysprofUserSampler *self,
+ gboolean enable)
+{
+ for (guint i = 0; i < self->perf_fds->len; i++)
+ {
+ int perf_fd = g_array_index (self->perf_fds, int, i);
+
+ if (0 != ioctl (perf_fd, enable ? PERF_EVENT_IOC_ENABLE : PERF_EVENT_IOC_DISABLE))
+ {
+ int errsv = errno;
+ g_warning ("Failed to toggle perf_fd: %s", g_strerror (errsv));
+ }
+ }
+}
+
+static char **
+sysprof_user_sampler_list_required_policy (SysprofInstrument *instrument)
+{
+ static const char *policy[] = {"org.gnome.sysprof3.profile", NULL};
+
+ return g_strdupv ((char **)policy);
+}
+
+typedef struct _Prepare
+{
+ SysprofRecording *recording;
+ SysprofUserSampler *sampler;
+ guint stack_size;
+} Prepare;
+
+static void
+prepare_free (Prepare *prepare)
+{
+ g_clear_object (&prepare->recording);
+ g_clear_object (&prepare->sampler);
+ g_free (prepare);
+}
+
+static void
+_perf_event_open_cb (GObject *object,
+ GAsyncResult *result,
+ gpointer user_data)
+{
+ GDBusConnection *connection = (GDBusConnection *)object;
+ g_autoptr(DexPromise) promise = user_data;
+ g_autoptr(GUnixFDList) fd_list = NULL;
+ g_autoptr(GVariant) ret = NULL;
+ g_autoptr(GError) error = NULL;
+
+ g_assert (G_IS_DBUS_CONNECTION (connection));
+ g_assert (G_IS_ASYNC_RESULT (result));
+ g_assert (DEX_IS_PROMISE (promise));
+
+ if ((ret = g_dbus_connection_call_with_unix_fd_list_finish (connection, &fd_list, result, &error)))
+ {
+ g_autofd int fd = -1;
+ int handle;
+
+ g_variant_get (ret, "(h)", &handle);
+
+ if (-1 == (fd = g_unix_fd_list_get (fd_list, handle, &error)))
+ goto failure;
+
+ dex_promise_resolve_fd (promise, g_steal_fd (&fd));
+ return;
+ }
+
+failure:
+ dex_promise_reject (promise, g_steal_pointer (&error));
+}
+
+static int
+_perf_event_open (GDBusConnection *connection,
+ int cpu,
+ guint stack_size,
+ GError **error)
+{
+ g_autoptr(DexPromise) promise = NULL;
+ g_autoptr(GVariant) options = NULL;
+ g_autofd int perf_fd = -1;
+ struct perf_event_attr attr = {0};
+ gboolean with_mmap2 = TRUE;
+ gboolean use_software = FALSE;
+
+ g_assert (G_IS_DBUS_CONNECTION (connection));
+
+try_again:
+ attr.sample_type = PERF_SAMPLE_IP
+ | PERF_SAMPLE_TID
+ | PERF_SAMPLE_IDENTIFIER
+ | PERF_SAMPLE_CALLCHAIN
+ | PERF_SAMPLE_STACK_USER
+ | PERF_SAMPLE_REGS_USER
+ | PERF_SAMPLE_TIME;
+ attr.wakeup_events = N_WAKEUP_EVENTS;
+ attr.disabled = TRUE;
+ attr.mmap = TRUE;
+ attr.mmap2 = with_mmap2;
+ attr.comm = 1;
+ attr.task = 1;
+ attr.exclude_idle = 1;
+ attr.sample_id_all = 1;
+
+#ifdef HAVE_PERF_CLOCKID
+ attr.clockid = sysprof_clock;
+ attr.use_clockid = 1;
+#endif
+
+ attr.sample_stack_user = stack_size;
+ attr.sample_regs_user = SYSPROF_ARCH_PREFERRED_REGS;
+
+ attr.size = sizeof attr;
+
+ if (use_software)
+ {
+ attr.type = PERF_TYPE_SOFTWARE;
+ attr.config = PERF_COUNT_SW_CPU_CLOCK;
+ attr.sample_period = 1000000;
+ }
+ else
+ {
+ attr.type = PERF_TYPE_HARDWARE;
+ attr.config = PERF_COUNT_HW_CPU_CYCLES;
+ attr.sample_period = 1200000;
+ }
+
+ options = _sysprof_perf_event_attr_to_variant (&attr);
+ promise = dex_promise_new ();
+
+ g_dbus_connection_call_with_unix_fd_list (connection,
+ "org.gnome.Sysprof3",
+ "/org/gnome/Sysprof3",
+ "org.gnome.Sysprof3.Service",
+ "PerfEventOpen",
+ g_variant_new ("(@a{sv}iiht)",
+ options,
+ -1,
+ cpu,
+ -1,
+ 0),
+ G_VARIANT_TYPE ("(h)"),
+ G_DBUS_CALL_FLAGS_NONE,
+ G_MAXUINT,
+ NULL,
+ NULL,
+ _perf_event_open_cb,
+ dex_ref (promise));
+
+ if (-1 == (perf_fd = dex_await_fd (dex_ref (promise), error)))
+ {
+ g_clear_pointer (&options, g_variant_unref);
+
+ if (with_mmap2)
+ {
+ with_mmap2 = FALSE;
+ goto try_again;
+ }
+
+ if (use_software == FALSE)
+ {
+ with_mmap2 = TRUE;
+ use_software = TRUE;
+ goto try_again;
+ }
+
+ return -1;
+ }
+
+ return g_steal_fd (&perf_fd);
+}
+
+static void
+call_unwind_cb (GObject *object,
+ GAsyncResult *result,
+ gpointer user_data)
+{
+ g_autoptr(DexPromise) promise = user_data;
+ g_autoptr(GUnixFDList) out_fd_list = NULL;
+ g_autoptr(GVariant) out_capture_fd = NULL;
+ g_autofd int capture_fd = -1;
+ GError *error = NULL;
+
+ g_assert (IPC_IS_UNWINDER (object));
+ g_assert (G_IS_ASYNC_RESULT (result));
+ g_assert (DEX_IS_PROMISE (promise));
+
+ if (ipc_unwinder_call_unwind_finish (IPC_UNWINDER (object), &out_capture_fd, &out_fd_list, result, &error) &&
+ -1 != (capture_fd = g_unix_fd_list_get (out_fd_list, g_variant_get_handle (out_capture_fd), &error)))
+ dex_promise_resolve_fd (promise, g_steal_fd (&capture_fd));
+ else
+ dex_promise_reject (promise, error);
+}
+
+static void
+create_unwinder_cb (GObject *object,
+ GAsyncResult *result,
+ gpointer user_data)
+{
+ g_autoptr(DexPromise) promise = user_data;
+ IpcUnwinder *unwinder;
+ GError *error = NULL;
+
+ if ((unwinder = ipc_unwinder_proxy_new_finish (result, &error)))
+ dex_promise_resolve_object (promise, unwinder);
+ else
+ dex_promise_reject (promise, error);
+}
+
+static IpcUnwinder *
+create_unwinder (GDBusConnection *connection,
+ GError **error)
+{
+ g_autoptr(DexPromise) promise = dex_promise_new ();
+ ipc_unwinder_proxy_new (connection, G_DBUS_PROXY_FLAGS_NONE,
+ "org.gnome.Sysprof3",
+ "/org/gnome/Sysprof3/Unwinder",
+ NULL,
+ create_unwinder_cb,
+ dex_ref (promise));
+ return dex_await_object (dex_ref (promise), error);
+}
+
+static DexFuture *
+sysprof_user_sampler_prepare_fiber (gpointer user_data)
+{
+ Prepare *prepare = user_data;
+ g_autoptr(GDBusConnection) connection = NULL;
+ g_autoptr(GUnixFDList) fd_list = NULL;
+ g_autoptr(GError) error = NULL;
+ GVariantBuilder builder;
+ gboolean all_failed = TRUE;
+ guint n_cpu;
+
+ g_assert (prepare != NULL);
+ g_assert (SYSPROF_IS_RECORDING (prepare->recording));
+ g_assert (SYSPROF_IS_USER_SAMPLER (prepare->sampler));
+
+ if (!(connection = dex_await_object (dex_bus_get (G_BUS_TYPE_SYSTEM), &error)))
+ return dex_future_new_for_error (g_steal_pointer (&error));
+
+ if (!dex_await (_sysprof_recording_add_file (prepare->recording,
+ "/proc/kallsyms",
+ TRUE),
+ &error))
+ {
+ _sysprof_recording_diagnostic (prepare->recording,
+ "Sampler",
+ "Failed to record copy of “kallsyms” to capture: %s",
+ error->message);
+ g_clear_error (&error);
+ }
+
+ n_cpu = g_get_num_processors ();
+ fd_list = g_unix_fd_list_new ();
+
+ g_variant_builder_init (&builder, G_VARIANT_TYPE ("a(hi)"));
+
+ for (guint i = 0; i < n_cpu; i++)
+ {
+ g_autofd int fd = _perf_event_open (connection, i, prepare->stack_size, &error);
+
+ if (fd == -1)
+ {
+ _sysprof_recording_diagnostic (prepare->recording,
+ "Sampler",
+ "Failed to load Perf event stream for CPU %d with stack size %u: %s",
+ i, prepare->stack_size, error->message);
+ g_clear_error (&error);
+ }
+ else
+ {
+ int handle = g_unix_fd_list_append (fd_list, fd, &error);
+
+ if (handle == -1)
+ {
+ _sysprof_recording_diagnostic (prepare->recording,
+ "Sampler",
+ "Out of FDs to add to FDList: %s",
+ error->message);
+ g_clear_error (&error);
+ }
+ else
+ {
+ g_array_append_val (prepare->sampler->perf_fds, fd);
+ fd = -1;
+
+ g_variant_builder_add (&builder, "(hi)", handle, i);
+
+ all_failed = FALSE;
+ }
+ }
+ }
+
+ if (!all_failed)
+ {
+ g_autoptr(IpcUnwinder) unwinder = create_unwinder (connection, &error);
+
+ if (unwinder == NULL)
+ {
+ _sysprof_recording_diagnostic (prepare->recording,
+ "Sampler",
+ "Failed to locate unwinder service: %s",
+ error->message);
+ g_clear_error (&error);
+ }
+ else
+ {
+ g_autoptr(DexPromise) promise = dex_promise_new ();
+ int event_fd_handle = g_unix_fd_list_append (fd_list, prepare->sampler->event_fd, NULL);
+ g_autofd int fd = -1;
+
+ ipc_unwinder_call_unwind (unwinder,
+ prepare->stack_size,
+ g_variant_builder_end (&builder),
+ g_variant_new_handle (event_fd_handle),
+ fd_list,
+ NULL,
+ call_unwind_cb,
+ dex_ref (promise));
+
+ fd = dex_await_fd (dex_ref (promise), &error);
+
+ if (fd == -1)
+ {
+ _sysprof_recording_diagnostic (prepare->recording,
+ "Sampler",
+ "Failed to setup user-space unwinder: %s",
+ error->message);
+ g_clear_error (&error);
+ }
+ else
+ {
+ prepare->sampler->capture_fd = g_steal_fd (&fd);
+ }
+ }
+ }
+
+ g_variant_builder_clear (&builder);
+
+ return dex_future_new_for_boolean (TRUE);
+}
+
+static DexFuture *
+sysprof_user_sampler_prepare (SysprofInstrument *instrument,
+ SysprofRecording *recording)
+{
+ SysprofUserSampler *self = (SysprofUserSampler *)instrument;
+ Prepare *prepare;
+
+ g_assert (SYSPROF_IS_INSTRUMENT (instrument));
+ g_assert (SYSPROF_IS_RECORDING (recording));
+
+ prepare = g_new0 (Prepare, 1);
+ prepare->recording = g_object_ref (recording);
+ prepare->sampler = g_object_ref (self);
+ prepare->stack_size = self->stack_size;
+
+ return dex_scheduler_spawn (NULL, 0,
+ sysprof_user_sampler_prepare_fiber,
+ prepare,
+ (GDestroyNotify)prepare_free);
+}
+
+typedef struct _Record
+{
+ SysprofRecording *recording;
+ SysprofUserSampler *sampler;
+ DexFuture *cancellable;
+} Record;
+
+static void
+record_free (Record *record)
+{
+ g_clear_object (&record->recording);
+ g_clear_object (&record->sampler);
+ dex_clear (&record->cancellable);
+ g_free (record);
+}
+
+static DexFuture *
+sysprof_user_sampler_record_fiber (gpointer user_data)
+{
+ SysprofCaptureWriter *writer;
+ Record *record = user_data;
+ g_autoptr(GError) error = NULL;
+ g_autoptr(GSource) muxer_source = NULL;
+ guint64 exiting = 1234;
+
+ g_assert (record != NULL);
+ g_assert (SYSPROF_IS_USER_SAMPLER (record->sampler));
+ g_assert (SYSPROF_IS_RECORDING (record->recording));
+ g_assert (DEX_IS_FUTURE (record->cancellable));
+
+ writer = _sysprof_recording_writer (record->recording);
+
+ sysprof_user_sampler_ioctl (record->sampler, TRUE);
+
+ g_debug ("Staring muxer for capture_fd");
+ muxer_source = sysprof_muxer_source_new (g_steal_fd (&record->sampler->capture_fd), writer);
+ g_source_set_static_name (muxer_source, "[stack-muxer]");
+ g_source_attach (muxer_source, NULL);
+
+ if (!dex_await (dex_ref (record->cancellable), &error))
+ g_debug ("UserSampler shutting down for reason: %s", error->message);
+
+ write (record->sampler->event_fd, &exiting, sizeof exiting);
+
+ g_source_destroy (muxer_source);
+
+ sysprof_user_sampler_ioctl (record->sampler, FALSE);
+
+ return dex_future_new_for_boolean (TRUE);
+}
+
+static DexFuture *
+sysprof_user_sampler_record (SysprofInstrument *instrument,
+ SysprofRecording *recording,
+ GCancellable *cancellable)
+{
+ SysprofUserSampler *self = (SysprofUserSampler *)instrument;
+ Record *record;
+
+ g_assert (SYSPROF_IS_INSTRUMENT (instrument));
+ g_assert (SYSPROF_IS_RECORDING (recording));
+ g_assert (!cancellable || G_IS_CANCELLABLE (cancellable));
+
+ record = g_new0 (Record, 1);
+ record->recording = g_object_ref (recording);
+ record->sampler = g_object_ref (self);
+ record->cancellable = dex_cancellable_new_from_cancellable (cancellable);
+
+ return dex_scheduler_spawn (NULL, 0,
+ sysprof_user_sampler_record_fiber,
+ record,
+ (GDestroyNotify)record_free);
+}
+
+static void
+sysprof_user_sampler_finalize (GObject *object)
+{
+ SysprofUserSampler *self = (SysprofUserSampler *)object;
+
+ g_clear_pointer (&self->perf_fds, g_array_unref);
+
+ g_clear_fd (&self->capture_fd, NULL);
+ g_clear_fd (&self->event_fd, NULL);
+
+ G_OBJECT_CLASS (sysprof_user_sampler_parent_class)->finalize (object);
+}
+
+static void
+sysprof_user_sampler_class_init (SysprofUserSamplerClass *klass)
+{
+ GObjectClass *object_class = G_OBJECT_CLASS (klass);
+ SysprofInstrumentClass *instrument_class = SYSPROF_INSTRUMENT_CLASS (klass);
+
+ object_class->finalize = sysprof_user_sampler_finalize;
+
+ instrument_class->list_required_policy = sysprof_user_sampler_list_required_policy;
+ instrument_class->prepare = sysprof_user_sampler_prepare;
+ instrument_class->record = sysprof_user_sampler_record;
+}
+
+static void
+sysprof_user_sampler_init (SysprofUserSampler *self)
+{
+ self->capture_fd = -1;
+ self->event_fd = eventfd (0, EFD_CLOEXEC);
+
+ self->perf_fds = g_array_new (FALSE, FALSE, sizeof (int));
+ g_array_set_clear_func (self->perf_fds, close_fd);
+}
+
+SysprofInstrument *
+sysprof_user_sampler_new (guint stack_size)
+{
+ SysprofUserSampler *self;
+
+ g_return_val_if_fail (stack_size > 0, NULL);
+ g_return_val_if_fail (stack_size % sysprof_getpagesize () == 0, NULL);
+
+ self = g_object_new (SYSPROF_TYPE_USER_SAMPLER, NULL);
+ self->stack_size = stack_size;
+
+ return SYSPROF_INSTRUMENT (self);
+}
diff --git a/src/libsysprof/sysprof-user-sampler.h b/src/libsysprof/sysprof-user-sampler.h
new file mode 100644
index 00000000..d39e6095
--- /dev/null
+++ b/src/libsysprof/sysprof-user-sampler.h
@@ -0,0 +1,43 @@
+/*
+ * sysprof-user-sampler.h
+ *
+ * Copyright 2024 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include "sysprof-instrument.h"
+
+G_BEGIN_DECLS
+
+#define SYSPROF_TYPE_USER_SAMPLER (sysprof_user_sampler_get_type())
+#define SYSPROF_IS_USER_SAMPLER(obj) G_TYPE_CHECK_INSTANCE_TYPE(obj, SYSPROF_TYPE_USER_SAMPLER)
+#define SYSPROF_USER_SAMPLER(obj) G_TYPE_CHECK_INSTANCE_CAST(obj, SYSPROF_TYPE_USER_SAMPLER, SysprofUserSampler)
+#define SYSPROF_USER_SAMPLER_CLASS(klass) G_TYPE_CHECK_CLASS_CAST(klass, SYSPROF_TYPE_USER_SAMPLER, SysprofUserSamplerClass)
+
+typedef struct _SysprofUserSampler SysprofUserSampler;
+typedef struct _SysprofUserSamplerClass SysprofUserSamplerClass;
+
+SYSPROF_AVAILABLE_IN_47
+GType sysprof_user_sampler_get_type (void) G_GNUC_CONST;
+SYSPROF_AVAILABLE_IN_47
+SysprofInstrument *sysprof_user_sampler_new (guint stack_size);
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (SysprofUserSampler, g_object_unref)
+
+G_END_DECLS
diff --git a/src/libsysprof/sysprof.h b/src/libsysprof/sysprof.h
index d30f9fd4..514e332b 100644
--- a/src/libsysprof/sysprof.h
+++ b/src/libsysprof/sysprof.h
@@ -89,6 +89,7 @@ G_BEGIN_DECLS
# include "sysprof-time-span.h"
# include "sysprof-tracefd-consumer.h"
# include "sysprof-tracer.h"
+# include "sysprof-user-sampler.h"
#undef SYSPROF_INSIDE
G_END_DECLS
--
2.45.2