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libdatadog 29.0.0: integrate libdatadog sample types #504

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f7b071b
chore: upgrade libdatadog to v28.0.2
r1viollet Mar 5, 2026
4326981
refactor: replace DDPROF_PWT_* enum with direct ddog_prof_SampleType …
r1viollet Mar 5, 2026
2b90274
fix(profiling): several fixes for libdatadog v28 migration
r1viollet Mar 6, 2026
5340a55
docs: rewrite profile sample type mapping for libdatadog v28
r1viollet Mar 6, 2026
475e553
style: align sample_type_name() cases with static_assert order
r1viollet Mar 6, 2026
d0147c5
chore: upgrade libdatadog to v29.0.0, fix sample type sentinel
r1viollet Mar 19, 2026
9b1872c
libdatadog 29: Add an include of libdatadog headers
r1viollet Mar 19, 2026
18c4729
libdatadog 29 - remove documentation on profile types
r1viollet Mar 19, 2026
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2 changes: 2 additions & 0 deletions CMakeLists.txt
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Expand Up @@ -89,6 +89,8 @@ find_package(absl REQUIRED)

# libdatadog_profiling
include(Findlibdatadog)
# watcher_sample_types.hpp includes <datadog/common.h>, so all targets need this.
include_directories(${Datadog_INCLUDE_DIR})

# Event Parser
add_subdirectory(src/event_parser)
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21 changes: 15 additions & 6 deletions cmake/Findlibdatadog.cmake
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Expand Up @@ -4,15 +4,24 @@

# libdatadog : common profiler imported libraries https://github.com/DataDog/libdatadog/releases
set(TAG_LIBDATADOG
"v26.0.0"
"v29.0.0"
CACHE STRING "libdatadog github tag")

set(Datadog_ROOT ${VENDOR_PATH}/libdatadog-${TAG_LIBDATADOG})
# Override with a local build by passing -DDatadog_LOCAL_ROOT=/path/to/libdatadog
set(Datadog_LOCAL_ROOT
""
CACHE PATH "Path to a local libdatadog build (skips GitHub download)")

message(STATUS "${CMAKE_SOURCE_DIR}/tools/fetch_libddprof.sh ${TAG_LIBDATADOG} ${LIBDATADOG_ROOT}")
execute_process(
COMMAND "${CMAKE_SOURCE_DIR}/tools/fetch_libdatadog.sh" ${TAG_LIBDATADOG} ${Datadog_ROOT}
WORKING_DIRECTORY ${CMAKE_SOURCE_DIR} COMMAND_ERROR_IS_FATAL ANY)
if(Datadog_LOCAL_ROOT)
message(STATUS "Using local libdatadog override: ${Datadog_LOCAL_ROOT}")
set(Datadog_ROOT ${Datadog_LOCAL_ROOT})
else()
set(Datadog_ROOT ${VENDOR_PATH}/libdatadog-${TAG_LIBDATADOG})
message(STATUS "${CMAKE_SOURCE_DIR}/tools/fetch_libdatadog.sh ${TAG_LIBDATADOG} ${Datadog_ROOT}")
execute_process(
COMMAND "${CMAKE_SOURCE_DIR}/tools/fetch_libdatadog.sh" ${TAG_LIBDATADOG} ${Datadog_ROOT}
WORKING_DIRECTORY ${CMAKE_SOURCE_DIR} COMMAND_ERROR_IS_FATAL ANY)
endif()

set(DataDog_DIR "${Datadog_ROOT}/cmake")

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79 changes: 27 additions & 52 deletions include/perf_watcher.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -7,10 +7,11 @@

#include "ddprof_defs.hpp"
#include "event_config.hpp"
#include <string>
#include "watcher_sample_types.hpp"

#include <cstdint>
#include <linux/perf_event.h>
#include <string>

namespace ddprof {

Expand Down Expand Up @@ -55,7 +56,9 @@ struct PerfWatcher {
int64_t sample_period;
uint64_t sample_frequency;
};
int sample_type_id; // index into the sample types defined in this header
WatcherSampleTypes sample_type_info; // pprof types for each aggregation mode
bool
pprof_active; // false = watcher does not contribute to pprof (e.g., sDUM)

EventConfValueSource value_source; // how to normalize the sample value
EventAggregationMode aggregation_mode;
Expand All @@ -76,27 +79,6 @@ struct PerfWatcher {
bool instrument_self; // do my own perf_event_open, etc
};

// The Datadog backend only understands pre-configured event types. Those
// types are defined here, and then referenced in the watcher
// The last column is a dependent type which is always aggregated as a count
// whenever the main type is aggregated.
// type, pprof, unit, live-pprof, sample_type,
// a, b, c, d, e,
#define PROFILE_TYPE_TABLE(X) \
X(NOCOUNT, "nocount", nocount, "undef", NOCOUNT) \
X(TRACEPOINT, "tracepoint", events, "undef", NOCOUNT) \
X(CPU_NANOS, "cpu-time", nanoseconds, "undef", CPU_SAMPLE) \
X(CPU_SAMPLE, "cpu-samples", count, "undef", NOCOUNT) \
X(ALLOC_SAMPLE, "alloc-samples", count, "inuse-objects", NOCOUNT) \
X(ALLOC_SPACE, "alloc-space", bytes, "inuse-space", ALLOC_SAMPLE)

// defines enum of profile types
#define X_ENUM(a, b, c, d, e) DDPROF_PWT_##a,
enum DDPROF_SAMPLE_TYPES : uint8_t {
PROFILE_TYPE_TABLE(X_ENUM) DDPROF_PWT_LENGTH,
};
#undef X_ENUM

// Define our own event type on top of perf event types
enum DDProfTypeId : uint8_t { kDDPROF_TYPE_CUSTOM = PERF_TYPE_MAX + 100 };

Expand Down Expand Up @@ -128,33 +110,33 @@ enum DDProfCustomCountId : uint8_t {
// events are marked as tracepoint unless they represent a well-known profiling
// type!
// clang-format off
// short desc perf event type perf event count type period/freq profile sample type addtl. configs
// short desc perf event type perf event count type period/freq sample types pprof_active addtl. configs
// cppcheck-suppress preprocessorErrorDirective
#define EVENT_CONFIG_TABLE(X) \
X(hCPU, "CPU Cycles", PERF_TYPE_HARDWARE, PERF_COUNT_HW_CPU_CYCLES, 99, DDPROF_PWT_TRACEPOINT, IS_FREQ) \
X(hREF, "Ref. CPU Cycles", PERF_TYPE_HARDWARE, PERF_COUNT_HW_REF_CPU_CYCLES, 1000, DDPROF_PWT_TRACEPOINT, IS_FREQ) \
X(hINST, "Instr. Count", PERF_TYPE_HARDWARE, PERF_COUNT_HW_INSTRUCTIONS, 1000, DDPROF_PWT_TRACEPOINT, IS_FREQ) \
X(hCREF, "Cache Ref.", PERF_TYPE_HARDWARE, PERF_COUNT_HW_CACHE_REFERENCES, 999, DDPROF_PWT_TRACEPOINT, {}) \
X(hCMISS, "Cache Miss", PERF_TYPE_HARDWARE, PERF_COUNT_HW_CACHE_MISSES, 999, DDPROF_PWT_TRACEPOINT, {}) \
X(hBRANCH, "Branche Instr.", PERF_TYPE_HARDWARE, PERF_COUNT_HW_BRANCH_INSTRUCTIONS, 999, DDPROF_PWT_TRACEPOINT, {}) \
X(hBMISS, "Branch Miss", PERF_TYPE_HARDWARE, PERF_COUNT_HW_BRANCH_MISSES, 999, DDPROF_PWT_TRACEPOINT, {}) \
X(hBUS, "Bus Cycles", PERF_TYPE_HARDWARE, PERF_COUNT_HW_BUS_CYCLES, 1000, DDPROF_PWT_TRACEPOINT, IS_FREQ) \
X(hBSTF, "Bus Stalls(F)", PERF_TYPE_HARDWARE, PERF_COUNT_HW_STALLED_CYCLES_FRONTEND, 1000, DDPROF_PWT_TRACEPOINT, IS_FREQ) \
X(hBSTB, "Bus Stalls(B)", PERF_TYPE_HARDWARE, PERF_COUNT_HW_STALLED_CYCLES_BACKEND, 1000, DDPROF_PWT_TRACEPOINT, IS_FREQ) \
X(sCPU, "CPU Time", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_TASK_CLOCK, 99, DDPROF_PWT_CPU_NANOS, IS_FREQ_TRY_KERNEL) \
X(sPF, "Page Faults", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_PAGE_FAULTS, 1, DDPROF_PWT_TRACEPOINT, USE_KERNEL) \
X(sCS, "Con. Switch", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_CONTEXT_SWITCHES, 1, DDPROF_PWT_TRACEPOINT, USE_KERNEL) \
X(sMig, "CPU Migrations", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_CPU_MIGRATIONS, 99, DDPROF_PWT_TRACEPOINT, IS_FREQ) \
X(sPFMAJ, "Major Faults", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_PAGE_FAULTS_MAJ, 99, DDPROF_PWT_TRACEPOINT, USE_KERNEL) \
X(sPFMIN, "Minor Faults", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_PAGE_FAULTS_MIN, 99, DDPROF_PWT_TRACEPOINT, USE_KERNEL) \
X(sALGN, "Align. Faults", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_ALIGNMENT_FAULTS, 99, DDPROF_PWT_TRACEPOINT, IS_FREQ) \
X(sEMU, "Emu. Faults", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_EMULATION_FAULTS, 99, DDPROF_PWT_TRACEPOINT, IS_FREQ) \
X(sDUM, "Dummy", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_DUMMY, 1, DDPROF_PWT_NOCOUNT, {}) \
X(sALLOC, "Allocations", kDDPROF_TYPE_CUSTOM, kDDPROF_COUNT_ALLOCATIONS, 524288, DDPROF_PWT_ALLOC_SPACE, SKIP_FRAMES)
X(hCPU, "CPU Cycles", PERF_TYPE_HARDWARE, PERF_COUNT_HW_CPU_CYCLES, 99, k_stype_tracepoint, true, IS_FREQ) \
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@nsavoire nsavoire Mar 19, 2026

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You could replace pprof_active with a dummy sample type (similarly to what was done before):

inline constexpr WatcherSampleTypes k_stype_dummy = {
    {k_stype_none,   k_stype_none},
    {k_stype_none, k_stype_none}};

inline constexpr bool is_pprof_active(const WatcherSampleTypes &st) {
  return st.sample_types[0] != k_stype_none;
}

X(hREF, "Ref. CPU Cycles", PERF_TYPE_HARDWARE, PERF_COUNT_HW_REF_CPU_CYCLES, 1000, k_stype_tracepoint, true, IS_FREQ) \
X(hINST, "Instr. Count", PERF_TYPE_HARDWARE, PERF_COUNT_HW_INSTRUCTIONS, 1000, k_stype_tracepoint, true, IS_FREQ) \
X(hCREF, "Cache Ref.", PERF_TYPE_HARDWARE, PERF_COUNT_HW_CACHE_REFERENCES, 999, k_stype_tracepoint, true, {}) \
X(hCMISS, "Cache Miss", PERF_TYPE_HARDWARE, PERF_COUNT_HW_CACHE_MISSES, 999, k_stype_tracepoint, true, {}) \
X(hBRANCH, "Branche Instr.", PERF_TYPE_HARDWARE, PERF_COUNT_HW_BRANCH_INSTRUCTIONS, 999, k_stype_tracepoint, true, {}) \
X(hBMISS, "Branch Miss", PERF_TYPE_HARDWARE, PERF_COUNT_HW_BRANCH_MISSES, 999, k_stype_tracepoint, true, {}) \
X(hBUS, "Bus Cycles", PERF_TYPE_HARDWARE, PERF_COUNT_HW_BUS_CYCLES, 1000, k_stype_tracepoint, true, IS_FREQ) \
X(hBSTF, "Bus Stalls(F)", PERF_TYPE_HARDWARE, PERF_COUNT_HW_STALLED_CYCLES_FRONTEND, 1000, k_stype_tracepoint, true, IS_FREQ) \
X(hBSTB, "Bus Stalls(B)", PERF_TYPE_HARDWARE, PERF_COUNT_HW_STALLED_CYCLES_BACKEND, 1000, k_stype_tracepoint, true, IS_FREQ) \
X(sCPU, "CPU Time", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_TASK_CLOCK, 99, k_stype_cpu, true, IS_FREQ_TRY_KERNEL) \
X(sPF, "Page Faults", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_PAGE_FAULTS, 1, k_stype_tracepoint, true, USE_KERNEL) \
X(sCS, "Con. Switch", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_CONTEXT_SWITCHES, 1, k_stype_tracepoint, true, USE_KERNEL) \
X(sMig, "CPU Migrations", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_CPU_MIGRATIONS, 99, k_stype_tracepoint, true, IS_FREQ) \
X(sPFMAJ, "Major Faults", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_PAGE_FAULTS_MAJ, 99, k_stype_tracepoint, true, USE_KERNEL) \
X(sPFMIN, "Minor Faults", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_PAGE_FAULTS_MIN, 99, k_stype_tracepoint, true, USE_KERNEL) \
X(sALGN, "Align. Faults", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_ALIGNMENT_FAULTS, 99, k_stype_tracepoint, true, IS_FREQ) \
X(sEMU, "Emu. Faults", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_EMULATION_FAULTS, 99, k_stype_tracepoint, true, IS_FREQ) \
X(sDUM, "Dummy", PERF_TYPE_SOFTWARE, PERF_COUNT_SW_DUMMY, 1, k_stype_tracepoint, false, {}) \
X(sALLOC, "Allocations", kDDPROF_TYPE_CUSTOM, kDDPROF_COUNT_ALLOCATIONS, 524288, k_stype_alloc, true, SKIP_FRAMES)

// clang-format on

#define X_ENUM(a, b, c, d, e, f, g) DDPROF_PWE_##a,
#define X_ENUM(a, b, c, d, e, f, g, h) DDPROF_PWE_##a,
enum DDPROF_EVENT_NAMES : int8_t {
DDPROF_PWE_TRACEPOINT = -1,
EVENT_CONFIG_TABLE(X_ENUM) DDPROF_PWE_LENGTH,
Expand All @@ -165,16 +147,9 @@ enum DDPROF_EVENT_NAMES : int8_t {
const PerfWatcher *ewatcher_from_idx(int idx);
const PerfWatcher *ewatcher_from_str(const char *str);
const PerfWatcher *tracepoint_default_watcher();
bool watcher_has_countable_sample_type(const PerfWatcher *watcher);
bool watcher_has_tracepoint(const PerfWatcher *watcher);
int watcher_to_count_sample_type_id(const PerfWatcher *watcher);
const char *event_type_name_from_idx(int idx);

// Helper functions for sample types
const char *sample_type_name_from_idx(int idx, EventAggregationModePos pos);
const char *sample_type_unit_from_idx(int idx);
int sample_type_id_to_count_sample_type_id(int idx);

// Helper functions, mostly for tests
uint64_t perf_event_default_sample_type();
void log_watcher(const PerfWatcher *w, int idx);
Expand Down
45 changes: 45 additions & 0 deletions include/watcher_sample_types.hpp
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@@ -0,0 +1,45 @@
// Unless explicitly stated otherwise all files in this repository are licensed
// under the Apache License Version 2.0. This product includes software
// developed at Datadog (https://www.datadoghq.com/). Copyright 2021-Present
// Datadog, Inc.

#pragma once

// Maps a watcher's event to pprof sample types for each aggregation mode.
// k_stype_none signals "no sample/count type for this aggregation mode".
// Fields are uint32_t (not the enum) to allow k_stype_none = UINT32_MAX,
// which lies outside the valid enum range.

#include "event_config.hpp"

#include <cstdint>
#include <datadog/common.h>

namespace ddprof {

struct WatcherSampleTypes {
uint32_t sample_types[kNbEventAggregationModes]; // [kSumPos, kLiveSumPos]
uint32_t count_types[kNbEventAggregationModes]; // companion counts
};

// Sentinel: slot is unused for this aggregation mode.
inline constexpr uint32_t k_stype_none = UINT32_MAX;

// Tracepoints: one event = one sample, no count companion, no live mode.
// clang-format off
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@r1viollet r1viollet Mar 19, 2026

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@nsavoire this part looks OK ? wdyt ?

inline constexpr WatcherSampleTypes k_stype_tracepoint = {
{DDOG_PROF_SAMPLE_TYPE_TRACEPOINT, k_stype_none},
{k_stype_none, k_stype_none}};

// CPU: nanoseconds in sum mode only — no live profile for CPU.
inline constexpr WatcherSampleTypes k_stype_cpu = {
{DDOG_PROF_SAMPLE_TYPE_CPU_TIME, k_stype_none},
{DDOG_PROF_SAMPLE_TYPE_CPU_SAMPLES, k_stype_none}};

// Allocation: bytes allocated / live bytes, with object-count companions.
inline constexpr WatcherSampleTypes k_stype_alloc = {
{DDOG_PROF_SAMPLE_TYPE_ALLOC_SPACE, DDOG_PROF_SAMPLE_TYPE_INUSE_SPACE},
{DDOG_PROF_SAMPLE_TYPE_ALLOC_SAMPLES, DDOG_PROF_SAMPLE_TYPE_INUSE_OBJECTS}};
// clang-format on

} // namespace ddprof
11 changes: 8 additions & 3 deletions src/exporter/ddprof_exporter.cc
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Expand Up @@ -49,7 +49,7 @@ DDRes create_pprof_file(ddog_Timespec start, const char *dbg_pprof_prefix,
strftime(time_start, std::size(time_start), "%Y%m%dT%H%M%SZ", tm_start);

char filename[PATH_MAX];
snprintf(filename, std::size(filename), "%s%s.pprof.lz4", dbg_pprof_prefix,
snprintf(filename, std::size(filename), "%s%s.pprof.zst", dbg_pprof_prefix,
time_start);
LG_NTC("[EXPORTER] Writing pprof to file %s", filename);
constexpr int read_write_user_only = 0600;
Expand Down Expand Up @@ -261,12 +261,17 @@ DDRes ddprof_exporter_new(const UserTags *user_tags, DDProfExporter *exporter) {
fill_stable_tags(user_tags, exporter, tags_exporter);

ddog_CharSlice const base_url = to_CharSlice(exporter->_url);
// ddprof is an out-of-process profiler and does not fork during export,
// so the system DNS resolver (/etc/resolv.conf) is safe and preferred.
constexpr bool k_use_system_resolver = true;
ddog_prof_Endpoint endpoint;
if (exporter->_agent) {
endpoint = ddog_prof_Endpoint_agent(base_url, k_timeout_ms);
endpoint =
ddog_prof_Endpoint_agent(base_url, k_timeout_ms, k_use_system_resolver);
} else {
ddog_CharSlice const api_key = to_CharSlice(exporter->_input.api_key);
endpoint = ddog_prof_Endpoint_agentless(base_url, api_key, k_timeout_ms);
endpoint = ddog_prof_Endpoint_agentless(base_url, api_key, k_timeout_ms,
k_use_system_resolver);
}

ddog_prof_ProfileExporter_Result res_exporter = ddog_prof_Exporter_new(
Expand Down
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