linux.git/tools/perf, branch v6.0-rc7

perf tools: Honor namespace when synthesizing build-ids

2022-09-21T19:08:00+00:00

It needs to enter the namespace before reading a file.

Fixes: 4183a8d70a288627 ("perf tools: Allow synthesizing the build id for kernel/modules/tasks in PERF_RECORD_MMAP2")
Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20220920222822.2171056-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf kcore_copy: Do not check /proc/modules is unchanged

2022-09-21T19:08:00+00:00

/proc/kallsyms and /proc/modules are compared before and after the copy
in order to ensure no changes during the copy.

However /proc/modules also might change due to reference counts changing
even though that does not make any difference.

Any modules loaded or unloaded should be visible in changes to kallsyms,
so it is not necessary to check /proc/modules also anyway.

Remove the comparison checking that /proc/modules is unchanged.

Fixes: fc1b691d7651d949 ("perf buildid-cache: Add ability to add kcore to the cache")
Reported-by: Daniel Dao 
Signed-off-by: Adrian Hunter 
Tested-by: Daniel Dao 
Acked-by: Namhyung Kim 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Link: https://lore.kernel.org/r/20220914122429.8770-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf record: Fix cpu mask bit setting for mixed mmaps

2022-09-21T19:08:00+00:00

With mixed per-thread and (system-wide) per-cpu maps, the "any cpu" value
 -1 must be skipped when setting CPU mask bits.

Prior to commit cbd7bfc7fd99acdd ("tools/perf: Fix out of bound access
to cpu mask array") the invalid setting went unnoticed, but since then
it causes perf record to fail with an error.

Example:

 Before:

   $ perf record -e intel_pt// --per-thread uname
   Failed to initialize parallel data streaming masks

 After:

   $ perf record -e intel_pt// --per-thread uname
   Linux
   [ perf record: Woken up 1 times to write data ]
   [ perf record: Captured and wrote 0.068 MB perf.data ]

Fixes: ae4f8ae16a078964 ("libperf evlist: Allow mixing per-thread and per-cpu mmaps")
Signed-off-by: Adrian Hunter 
Acked-by: Namhyung Kim 
Cc: Athira Rajeev 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220915122612.81738-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Skip wp modify test on old kernels

2022-09-21T19:07:32+00:00

It uses PERF_EVENT_IOC_MODIFY_ATTRIBUTES ioctl.	 The kernel would return
ENOTTY if it's not supported.  Update the skip reason in that case.

Committer notes:

On s/390 the args aren't used, so need to be marked __maybe_unused.

Reviewed-by: Ravi Bangoria 
Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Link: https://lore.kernel.org/r/20220914183338.546357-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf jit: Include program header in ELF files

2022-09-21T13:30:55+00:00

The missing header makes it hard for programs like elfutils to open
these files.

Fixes: 2d86612aacb7805f ("perf symbol: Correct address for bss symbols")
Reviewed-by: Leo Yan 
Signed-off-by: Lieven Hey 
Tested-by: Leo Yan 
Cc: Leo Yan 
Link: https://lore.kernel.org/r/20220915092910.711036-1-lieven.hey@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Add a new test for perf stat cgroup BPF counter

2022-09-21T13:30:55+00:00

  $ sudo ./perf test -v each-cgroup
   96: perf stat --bpf-counters --for-each-cgroup test                 :
  --- start ---
  test child forked, pid 79600
  test child finished with 0
  ---- end ----
  perf stat --bpf-counters --for-each-cgroup test: Ok

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20220916184132.1161506-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Use evsel->core.cpus to iterate cpus in BPF cgroup counters

2022-09-21T13:30:55+00:00

If it mixes core and uncore events, each evsel would have different cpu map.
But it assumed they are same with evlist's all_cpus and accessed by the same
index.  This resulted in a crash like below.

  $ perf stat -a --bpf-counters --for-each_cgroup ^. -e cycles,imc/cas_count_read/ sleep 1
  Segmentation fault

While it's not recommended to use uncore events for cgroup aggregation, it
should not crash.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20220916184132.1161506-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Fix cpu map index in bperf cgroup code

2022-09-21T13:30:55+00:00

The previous cpu map introduced a bug in the bperf cgroup counter.  This
results in a failure when user gives a partial cpu map starting from
non-zero.

  $ sudo ./perf stat -C 1-2 --bpf-counters --for-each-cgroup ^. sleep 1
  libbpf: prog 'on_cgrp_switch': failed to create BPF link for perf_event FD 0:
                                 -9 (Bad file descriptor)
  Failed to attach cgroup program

To get the FD of an evsel, it should use a map index not the CPU number.

Fixes: 0255571a16059c8e ("perf cpumap: Switch to using perf_cpu_map API")
Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: bpf@vger.kernel.org
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Song Liu 
Link: https://lore.kernel.org/r/20220916184132.1161506-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Fix BPF program section name

2022-09-21T13:30:55+00:00

It seems the recent libbpf got more strict about the section name.
I'm seeing a failure like this:

  $ sudo ./perf stat -a --bpf-counters --for-each-cgroup ^. sleep 1
  libbpf: prog 'on_cgrp_switch': missing BPF prog type, check ELF section name 'perf_events'
  libbpf: prog 'on_cgrp_switch': failed to load: -22
  libbpf: failed to load object 'bperf_cgroup_bpf'
  libbpf: failed to load BPF skeleton 'bperf_cgroup_bpf': -22
  Failed to load cgroup skeleton

The section name should be 'perf_event' (without the trailing 's').
Although it's related to the libbpf change, it'd be better fix the
section name in the first place.

Fixes: 944138f048f7d759 ("perf stat: Enable BPF counter with --for-each-cgroup")
Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: bpf@vger.kernel.org
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Song Liu 
Link: https://lore.kernel.org/r/20220916184132.1161506-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf record: Fix synthesis failure warnings

2022-09-08T18:57:37+00:00

Some calls to synthesis functions set err < 0 but only warn about the
failure and continue.  However they do not set err back to zero, relying
on subsequent code to do that.

That changed with the introduction of option --synth. When --synth=no
subsequent functions that set err back to zero are not called.

Fix by setting err = 0 in those cases.

Example:

 Before:

   $ perf record --no-bpf-event --synth=all -o /tmp/huh uname
   Couldn't synthesize bpf events.
   Linux
   [ perf record: Woken up 1 times to write data ]
   [ perf record: Captured and wrote 0.014 MB /tmp/huh (7 samples) ]
   $ perf record --no-bpf-event --synth=no -o /tmp/huh uname
   Couldn't synthesize bpf events.

 After:

   $ perf record --no-bpf-event --synth=no -o /tmp/huh uname
   Couldn't synthesize bpf events.
   Linux
   [ perf record: Woken up 1 times to write data ]
   [ perf record: Captured and wrote 0.014 MB /tmp/huh (7 samples) ]

Fixes: 41b740b6e8a994e5 ("perf record: Add --synth option")
Signed-off-by: Adrian Hunter 
Acked-by: Namhyung Kim 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lore.kernel.org/r/20220907162458.72817-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo