linux.git/tools/lib/perf/include, branch v6.18.21

libperf event: Ensure tracing data is multiple of 8 sized

2025-09-03T15:34:54+00:00

Perf's synthetic-events.c will ensure 8-byte alignment of tracing
data, writing it after a perf_record_header_tracing_data event.

Add padding to struct perf_record_header_tracing_data to make it 16-byte
rather than 12-byte sized.

Fixes: 055c67ed39887c55 ("perf tools: Move event synthesizing routines to separate .c file")
Reviewed-by: James Clark 
Signed-off-by: Ian Rogers 
Acked-by: Namhyung Kim 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Athira Rajeev 
Cc: Blake Jones 
Cc: Chun-Tse Shao 
Cc: Collin Funk 
Cc: Howard Chu 
Cc: Ingo Molnar 
Cc: Jan Polensky 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Li Huafei 
Cc: Mark Rutland 
Cc: Nam Cao 
Cc: Peter Zijlstra 
Cc: Steinar H. Gunderson 
Cc: Thomas Gleixner 
Link: https://lore.kernel.org/r/20250821163820.1132977-6-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

libperf evsel: Factor perf_evsel__exit out of perf_evsel__delete

2025-07-24T20:41:35+00:00

This allows the perf_evsel__exit to be called when the struct
perf_evsel is embedded inside another struct, such as struct evsel in
perf.

Reviewed-by: Thomas Falcon 
Signed-off-by: Ian Rogers 
Tested-by: James Clark 
Link: https://lore.kernel.org/r/20250719030517.1990983-8-irogers@google.com
Signed-off-by: Namhyung Kim

libperf evsel: Rename own_cpus to pmu_cpus

2025-07-24T20:41:35+00:00

own_cpus is generally the cpumask from the PMU. Rename to pmu_cpus to
try to make this clearer. Variable rename with no other changes.

Reviewed-by: Thomas Falcon 
Signed-off-by: Ian Rogers 
Tested-by: James Clark 
Link: https://lore.kernel.org/r/20250719030517.1990983-7-irogers@google.com
Signed-off-by: Namhyung Kim

perf record: collect BPF metadata from existing BPF programs

2025-06-20T21:48:35+00:00

Look for .rodata maps, find ones with 'bpf_metadata_' variables, extract
their values as strings, and create a new PERF_RECORD_BPF_METADATA
synthetic event using that data. The code gets invoked from the existing
routine perf_event__synthesize_one_bpf_prog().

For example, a BPF program with the following variables:

    const char bpf_metadata_version[] SEC(".rodata") = "3.14159";
    int bpf_metadata_value[] SEC(".rodata") = 42;

would generate a PERF_RECORD_BPF_METADATA record with:

    .prog_name        = 
    .nr_entries       = 2
    .entries[0].key   = "version"
    .entries[0].value = "3.14159"
    .entries[1].key   = "value"
    .entries[1].value = "42"

Each of the BPF programs and subprograms that share those variables would
get a distinct PERF_RECORD_BPF_METADATA record, with the ".prog_name"
showing the name of each program or subprogram. The prog_name is
deliberately the same as the ".name" field in the corresponding
PERF_RECORD_KSYMBOL record.

This code only gets invoked if support for displaying BTF char arrays
as strings is detected.

Signed-off-by: Blake Jones 
Link: https://lore.kernel.org/r/20250612194939.162730-3-blakejones@google.com
Signed-off-by: Namhyung Kim

libperf threadmap: Add perf_thread_map__idx()

2025-05-21T18:07:13+00:00

Allow computation of thread map index from a PID.

Note, with a 'struct perf_cpu_map' the sorted nature allows for a binary
search to compute the index which isn't currently possible with a
'struct perf_thread_map' as they aren't guaranteed sorted.

Signed-off-by: Ian Rogers 
Acked-by: Gautam Menghani 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Howard Chu 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Madhavan Srinivasan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20250519195148.1708988-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf record: Add 8-byte aligned event type PERF_RECORD_COMPRESSED2

2025-05-16T20:31:40+00:00

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

libperf cpumap: Add ability to create CPU from a single CPU number

2025-05-12T17:18:16+00:00

Add perf_cpu_map__new_int() so that a CPU map can be created from a
single integer.

Signed-off-by: Ian Rogers 
Tested-by: Kan Liang 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Dominique Martinet 
Cc: Greg Kroah-Hartman 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Weilin Wang 
Cc: Yicong Yang 
Link: https://lore.kernel.org/r/20250403194337.40202-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: Reduce cpu size from int to int16_t

2025-02-27T16:47:25+00:00

Fewer than 32k logical CPUs are currently supported by perf. A cpumap
is indexed by an integer (see perf_cpu_map__cpu) yielding a perf_cpu
that wraps a 4-byte int for the logical CPU - the wrapping is done
deliberately to avoid confusing a logical CPU with an index into a
cpumap. Using a 4-byte int within the perf_cpu is larger than required
so this patch reduces it to the 2-byte int16_t. For a cpumap
containing 16 entries this will reduce the array size from 64 to 32
bytes. For very large servers with lots of logical CPUs the size
savings will be greater.

Signed-off-by: Ian Rogers 
Reviewed-by: James Clark 
Link: https://lore.kernel.org/r/20250210191231.156294-1-irogers@google.com
Signed-off-by: Namhyung Kim

libperf cpumap: Remove perf_cpu_map__read()

2024-12-09T20:52:41+00:00

Function is no longer used and duplicates the parsing logic from
perf_cpu_map__new().

Remove to allow simplification.

Reviewed-by: Leo Yan 
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ben Gainey 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Kyle Meyer 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20241206044035.1062032-8-irogers@google.com
[ Applied manually to cope with "libperf cpumap: Refactor perf_cpu_map__merge()" ]
Signed-off-by: Arnaldo Carvalho de Melo

libperf cpumap: Hide/reduce scope of MAX_NR_CPUS

2024-12-09T20:52:41+00:00

Avoid redefinition of MAX_NR_CPUS as a global constant, the original
definition is tools/perf/perf.h.

Reviewed-by: Leo Yan 
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ben Gainey 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Kyle Meyer 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20241206044035.1062032-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo