linux.git/tools/lib/perf, branch v6.0-rc2

libperf: Add a test case for read formats

2022-08-19T18:56:44+00:00

It checks a various combination of the read format settings and verify
it return the value in a proper position.  The test uses task-clock
software events to guarantee it's always active and sets enabled/running
time.

Signed-off-by: Namhyung Kim 
Acked-by: Jiri Olsa 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20220819003644.508916-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

libperf: Handle read format in perf_evsel__read()

2022-08-19T18:56:27+00:00

The perf_counts_values should be increased to read the new lost data.
Also adjust values after read according the read format.

This supports PERF_FORMAT_GROUP which has a different data format but
it's only available for leader events.  Currently it doesn't have an API
to read sibling (member) events in the group.  But users may read the
sibling event directly.

Also reading from mmap would be disabled when the read format has ID or
LOST bit as it's not exposed via mmap.

Signed-off-by: Namhyung Kim 
Acked-by: Jiri Olsa 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20220819003644.508916-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: Fix alignment for masks in event encoding

2022-08-19T18:30:28+00:00

A mask encoding of a cpu map is laid out as:

  u16 nr
  u16 long_size
  unsigned long mask[];

However, the mask may be 8-byte aligned meaning there is a 4-byte pad
after long_size. This means 32-bit and 64-bit builds see the mask as
being at different offsets. On top of this the structure is in the byte
data[] encoded as:

  u16 type
  char data[]

This means the mask's struct isn't the required 4 or 8 byte aligned, but
is offset by 2. Consequently the long reads and writes are causing
undefined behavior as the alignment is broken.

Fix the mask struct by creating explicit 32 and 64-bit variants, use a
union to avoid data[] and casts; the struct must be packed so the
layout matches the existing perf.data layout. Taking an address of a
member of a packed struct breaks alignment so pass the packed
perf_record_cpu_map_data to functions, so they can access variables with
the right alignment.

As the 64-bit version has 4 bytes of padding, optimizing writing to only
write the 32-bit version.

Committer notes:

Disable warnings about 'packed' that break the build in some arches like
riscv64, but just around that specific struct.

Signed-off-by: Ian Rogers 
Acked-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexey Bayduraev 
Cc: Athira Jajeev 
Cc: Colin Ian King 
Cc: Dave Marchevsky 
Cc: German Gomez 
Cc: Gustavo A. R. Silva 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Kees Kook 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Riccardo Mancini 
Cc: Song Liu 
Cc: Stephane Eranian 
Link: https://lore.kernel.org/r/20220614143353.1559597-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: Const map for max()

2022-08-19T15:26:58+00:00

Allows max() to be used with 'const struct perf_cpu_maps *'.

Signed-off-by: Ian Rogers 
Acked-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexey Bayduraev 
Cc: Athira Jajeev 
Cc: Colin Ian King 
Cc: Dave Marchevsky 
Cc: German Gomez 
Cc: Gustavo A. R. Silva 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Kees Kook 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Riccardo Mancini 
Cc: Song Liu 
Cc: Stephane Eranian 
Link: https://lore.kernel.org/r/20220614143353.1559597-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf auxtrace: Add machine_pid and vcpu to auxtrace_error

2022-07-20T14:08:17+00:00

Add machine_pid and vcpu to struct perf_record_auxtrace_error. The existing
fmt member is used to identify the new format.

The new members make it possible to easily differentiate errors from guest
machines.

Signed-off-by: Adrian Hunter 
Acked-by: Ian Rogers 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: kvm@vger.kernel.org
Link: https://lore.kernel.org/r/20220711093218.10967-18-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add machine_pid and vcpu to id_index

2022-07-20T14:07:58+00:00

When injecting events from a guest perf.data file, the events will have
separate sample ID numbers. These ID numbers can then be used to determine
which machine an event belongs to. To facilitate that, add machine_pid and
vcpu to id_index records. For backward compatibility, these are added at
the end of the record, and the length of the record is used to determine
if they are present or not.

Note, this is needed because the events from a guest perf.data file contain
the pid/tid of the process running at that time inside the VM not the
pid/tid of the (QEMU) hypervisor thread. So a way is needed to relate
guest events back to the guest machine and VCPU, and using sample ID
numbers for that is relatively simple and convenient.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: kvm@vger.kernel.org
Link: https://lore.kernel.org/r/20220711093218.10967-11-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf record: Add finished init event

2022-06-23T14:54:22+00:00

In preparation for recording sideband events in a virtual machine guest so
that they can be injected into a host perf.data file.

This is needed to enable injecting events after the initial synthesized
user events (that have an all zero id sample) but before regular events.

Committer notes:

Add entry about PERF_RECORD_FINISHED_INIT to
tools/perf/Documentation/perf.data-file-format.txt.

Committer testing:

Before:

  # perf report -D | grep FINISHED
  0 0x5910 [0x8]: PERF_RECORD_FINISHED_ROUND
    FINISHED_ROUND events:          1  ( 0.5%)
  #

After:

  # perf record -- sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.020 MB perf.data (7 samples) ]
  # perf report -D | grep FINISHED
  0 0x5068 [0x8]: PERF_RECORD_FINISHED_INIT: unhandled!
  0 0x5390 [0x8]: PERF_RECORD_FINISHED_ROUND
    FINISHED_ROUND events:          1  ( 0.5%)
     FINISHED_INIT events:          1  ( 0.5%)
  #

Signed-off-by: Adrian Hunter 
Acked-by: Ian Rogers 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lore.kernel.org/r/20220610113316.6682-5-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

libperf evsel: Open shouldn't leak fd on failure

2022-06-19T13:41:43+00:00

If perf_event_open() fails the fd is opened but it is only freed by
closing (not by delete).

Typically when an open fails you don't call close and so this results in
a memory leak. To avoid this, add a close when open fails.

Signed-off-by: Ian Rogers 
Reviewed-By: Kajol Jain 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Anshuman Khandual 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Rob Herring 
Cc: Stephane Eranian 
Link: https://lore.kernel.org/r/20220609052355.1300162-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Allow system-wide events to keep their own threads

2022-05-26T15:36:57+00:00

System-wide events do not have threads, so do not propagate threads to
them.

Signed-off-by: Adrian Hunter 
Acked-by: Ian Rogers 
Acked-by: Namhyung Kim 
Cc: Alexey Bayduraev 
Cc: Jiri Olsa 
Cc: Leo Yan 
Link: https://lore.kernel.org/r/20220524075436.29144-16-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Allow system-wide events to keep their own CPUs

2022-05-26T15:36:57+00:00

Currently, user_requested_cpus supplants system-wide CPUs when the evlist
has_user_cpus. Change that so that system-wide events retain their own
CPUs and they are added to all_cpus.

Signed-off-by: Adrian Hunter 
Acked-by: Ian Rogers 
Acked-by: Namhyung Kim 
Cc: Alexey Bayduraev 
Cc: Jiri Olsa 
Cc: Leo Yan 
Link: https://lore.kernel.org/r/20220524075436.29144-15-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo