kernel.git/tools/perf/util/event.c, branch linux-rolling-stable

perf tools: Minimal DEFERRED_CALLCHAIN support

2025-12-03T00:13:32Z

Add a new event type for deferred callchains and a new callback for the struct perf_tool. For now it doesn't actually handle the deferred callchains but it just marks the sample if it has the PERF_CONTEXT_ USER_DEFFERED in the callchain array. At least, perf report can dump the raw data with this change. Actually this requires the next commit to enable attr.defer_callchain, but if you already have a data file, it'll show the following result. $ perf report -D ... 0x2158@perf.data [0x40]: event: 22 . . ... raw event: size 64 bytes . 0000: 16 00 00 00 02 00 40 00 06 00 00 00 0b 00 00 00 ......@......... . 0010: 03 00 00 00 00 00 00 00 a7 7f 33 fe 18 7f 00 00 ..........3..... . 0020: 0f 0e 33 fe 18 7f 00 00 48 14 33 fe 18 7f 00 00 ..3.....H.3..... . 0030: 08 09 00 00 08 09 00 00 e6 7a e7 35 1c 00 00 00 .........z.5.... 121163447014 0x2158 [0x40]: PERF_RECORD_CALLCHAIN_DEFERRED(IP, 0x2): 2312/2312: 0xb00000006 ... FP chain: nr:3 ..... 0: 00007f18fe337fa7 ..... 1: 00007f18fe330e0f ..... 2: 00007f18fe331448 : unhandled! Reviewed-by: Ian Rogers Signed-off-by: Namhyung Kim

perf build-id: Change sprintf functions to snprintf

2025-07-25T17:37:13Z

Pass in a size argument rather than implying all build id strings must be SBUILD_ID_SIZE. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250724163302.596743-4-irogers@google.com [ fixed some build errors ] Signed-off-by: Namhyung Kim

perf tools: display the new PERF_RECORD_BPF_METADATA event

2025-06-20T21:48:56Z

Here's some example "perf script -D" output for the new event type. The ": unhandled!" message is from tool.c, analogous to other behavior there. I've elided some rows with all NUL characters for brevity, and I wrapped one of the >75-column lines to fit in the commit guidelines. 0x50fc8@perf.data [0x260]: event: 84 . . ... raw event: size 608 bytes . 0000: 54 00 00 00 00 00 60 02 62 70 66 5f 70 72 6f 67 T.....`.bpf_prog . 0010: 5f 31 65 30 61 32 65 33 36 36 65 35 36 66 31 61 _1e0a2e366e56f1a . 0020: 32 5f 70 65 72 66 5f 73 61 6d 70 6c 65 5f 66 69 2_perf_sample_fi . 0030: 6c 74 65 72 00 00 00 00 00 00 00 00 00 00 00 00 lter............ . 0040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [...] . 0110: 74 65 73 74 5f 76 61 6c 75 65 00 00 00 00 00 00 test_value...... . 0120: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [...] . 0150: 34 32 00 00 00 00 00 00 00 00 00 00 00 00 00 00 42.............. . 0160: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [...] 0 0x50fc8 [0x260]: PERF_RECORD_BPF_METADATA \ prog bpf_prog_1e0a2e366e56f1a2_perf_sample_filter entry 0: test_value = 42 : unhandled! Signed-off-by: Blake Jones Link: https://lore.kernel.org/r/20250612194939.162730-5-blakejones@google.com Signed-off-by: Namhyung Kim

perf script: Print PERF_AUX_FLAG_COLLISION flag

2025-05-28T18:08:25Z

Print out the collision flag for AUX trace data. This is helpful for inspecting sample collisions. After: 0x217b60@/data_nvme1n1/niayan01/upstream/perf.data [0x40]: event: 11 . . ... raw event: size 64 bytes . 0000: 0b 00 00 00 00 00 40 00 d2 ef 3f 00 00 00 00 00 ......@...?..... . 0010: ff 0f 00 00 00 00 00 00 08 00 00 00 00 00 00 00 ................ . 0020: 1c 01 00 00 1c 01 00 00 10 bf 38 d6 11 01 00 00 ..........8..... . 0030: 03 00 00 00 00 00 00 00 06 00 00 00 00 00 00 00 ................ 3 1176120114960 0x217b60 [0x40]: PERF_RECORD_AUX offset: 0x3fefd2 size: 0xfff flags: 0x8 [C] The added character '[C]' indicates the collision. Signed-off-by: Leo Yan Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Kan Liang Cc: Namhyung Kim Link: https://lore.kernel.org/r/20250528153519.188644-1-leo.yan@arm.com Signed-off-by: Arnaldo Carvalho de Melo

perf record: Add 8-byte aligned event type PERF_RECORD_COMPRESSED2

2025-05-16T20:31:40Z

The original PERF_RECORD_COMPRESS is not 8-byte aligned, which can cause asan runtime error: # Build with asan $ make -C tools/perf O=/tmp/perf DEBUG=1 EXTRA_CFLAGS="-O0 -g -fno-omit-frame-pointer -fsanitize=undefined" # Test success with many asan runtime errors: $ /tmp/perf/perf test "Zstd perf.data compression/decompression" -vv 83: Zstd perf.data compression/decompression: ... util/session.c:1959:13: runtime error: member access within misaligned address 0x7f69e3f99653 for type 'union perf_event', which requires 13 byte alignment 0x7f69e3f99653: note: pointer points here d0 3a 50 69 44 00 00 00 00 00 08 00 bb 07 00 00 00 00 00 00 44 00 00 00 00 00 00 00 ff 07 00 00 ^ util/session.c:2163:22: runtime error: member access within misaligned address 0x7f69e3f99653 for type 'union perf_event', which requires 8 byte alignment 0x7f69e3f99653: note: pointer points here d0 3a 50 69 44 00 00 00 00 00 08 00 bb 07 00 00 00 00 00 00 44 00 00 00 00 00 00 00 ff 07 00 00 ^ ... Since there is no way to align compressed data in zstd compression, this patch add a new event type `PERF_RECORD_COMPRESSED2`, which adds a field `data_size` to specify the actual compressed data size. The `header.size` contains the total record size, including the padding at the end to make it 8-byte aligned. Tested with `Zstd perf.data compression/decompression` Signed-off-by: Chun-Tse Shao Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ben Gainey Cc: Christophe Leroy Cc: Ian Rogers Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Kan Liang Cc: Leo Yan Cc: Mark Rutland Cc: Namhyung Kim Cc: Nick Terrell Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20250303183646.327510-1-ctshao@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf report: Add latency output field

2025-02-18T22:04:32Z

Latency output field is similar to overhead, but represents overhead for latency rather than CPU consumption. It's re-scaled from overhead by dividing weight by the current parallelism level at the time of the sample. It effectively models profiling with 1 sample taken per unit of wall-clock time rather than unit of CPU time. Signed-off-by: Dmitry Vyukov Reviewed-by: Andi Kleen Link: https://lore.kernel.org/r/b6269518758c2166e6ffdc2f0e24cfdecc8ef9c1.1739437531.git.dvyukov@google.com Signed-off-by: Namhyung Kim

perf report: Add parallelism filter

2025-02-18T22:04:32Z

Add parallelism filter that can be used to look at specific parallelism levels only. The format is the same as cpu lists. For example: Only single-threaded samples: --parallelism=1 Low parallelism only: --parallelism=1-4 High parallelism only: --parallelism=64-128 Signed-off-by: Dmitry Vyukov Reviewed-by: Andi Kleen Link: https://lore.kernel.org/r/e61348985ff0a6a14b07c39e880edbd60a8f8635.1739437531.git.dvyukov@google.com Signed-off-by: Namhyung Kim

perf report: Add machine parallelism

2025-02-18T06:00:50Z

Add calculation of the current parallelism level (number of threads actively running on CPUs). The parallelism level can be shown in reports on its own, and to calculate latency overheads. Signed-off-by: Dmitry Vyukov Reviewed-by: Andi Kleen Link: https://lore.kernel.org/r/0f8c1b8eb12619029e31b3d5c0346f4616a5aeda.1739437531.git.dvyukov@google.com Signed-off-by: Namhyung Kim

perf buildid-list: Use perf_tool__init

2024-08-12T21:07:10Z

Reduce scope of build_id__mark_dso_hit_ops() to the scope of function perf_session__list_build_ids, its only use, and use perf_tool__init() for the default values. Move perf_event__exit_del_thread() to event.[ch] so it can be used in builtin-buildid-list.c. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Anshuman Khandual Cc: Athira Rajeev Cc: Huacai Chen Cc: Ilkka Koskinen Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Jonathan Cameron Cc: Kan Liang Cc: Leo Yan Cc: Mark Rutland Cc: Mike Leach Cc: Namhyung Kim Cc: Nick Desaulniers Cc: Nick Terrell Cc: Oliver Upton Cc: Peter Zijlstra Cc: Song Liu Cc: Sun Haiyong Cc: Suzuki Poulouse Cc: Will Deacon Cc: Yanteng Si Cc: Yicong Yang Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20240812204720.631678-8-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf tool: Constify tool pointers

2024-08-12T21:05:14Z

The tool pointer (to a struct largely of function pointers) is passed around but is unchanged except at initialization. Change parameter and variable types to be const to lower the possibilities of what could happen with a tool. Reviewed-by: Adrian Hunter Signed-off-by: Ian Rogers Tested-by: Adrian Hunter Tested-by: Leo Yan Cc: Alexander Shishkin Cc: Anshuman Khandual Cc: Athira Rajeev Cc: Huacai Chen Cc: Ilkka Koskinen Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Jonathan Cameron Cc: Kan Liang Cc: Leo Yan Cc: Mark Rutland Cc: Mike Leach Cc: Namhyung Kim Cc: Nick Desaulniers Cc: Nick Terrell Cc: Oliver Upton Cc: Peter Zijlstra Cc: Song Liu Cc: Sun Haiyong Cc: Suzuki Poulouse Cc: Will Deacon Cc: Yanteng Si Cc: Yicong Yang Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20240812204720.631678-4-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo