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

perf tools: Support reading PERF_FORMAT_LOST

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

The recent kernel added lost count can be read from either read(2) or
ring buffer data with PERF_SAMPLE_READ.  As it's a variable length data
we need to access it according to the format info.

But for perf tools use cases, PERF_FORMAT_ID is always set.  So we can
only check PERF_FORMAT_LOST bit to determine the data format.

Add sample_read_value_size() and next_sample_read_value() helpers to
make it a bit easier to access.  Use them in all places where it reads
the struct sample_read_value.

Signed-off-by: Namhyung Kim 
Acked-by: Jiri Olsa 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20220819003644.508916-5-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: Compute mask size in constant time

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

perf_cpu_map__max() computes the cpumap's maximum value, no need to
iterate over all values.

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/20220614143353.1559597-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: Synthetic events and const/static

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

Make the cpumap arguments const to make it clearer they are in rather
than out arguments. Make two functions static and remove external
declarations.

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/20220614143353.1559597-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf metrics: Copy entire pmu_event in find metric

2022-08-13T18:02:21+00:00

The pmu_event passed to the pmu_events_table_for_each_event is invalid
after the loop. Copy the entire struct in metricgroup__find_metric.
Reduce the scope of this function to static.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Stephane Eranian 
Cc: Will Deacon 
Cc: Xing Zhengjun 
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220812230949.683239-13-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf pmu-events: Hide the pmu_events

2022-08-13T18:02:08+00:00

Hide that the pmu_event structs are an array with a new wrapper struct.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Stephane Eranian 
Cc: Will Deacon 
Cc: Xing Zhengjun 
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220812230949.683239-12-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf pmu-events: Don't assume pmu_event is an array

2022-08-13T18:01:31+00:00

The current code assumes that a struct pmu_event can be iterated over
forward until a NULL pmu_event is encountered.

This makes it difficult to refactor pmu_event.

Add a loop function taking a callback function that's passed the struct
pmu_event.

This way the pmu_event is only needed for one element and not an entire
array.

Switch existing code iterating over the pmu_event arrays to use the new
loop function pmu_events_table_for_each_event.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Stephane Eranian 
Cc: Will Deacon 
Cc: Xing Zhengjun 
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220812230949.683239-11-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf pmu-events: Hide pmu_events_map

2022-08-13T18:00:47+00:00

Move usage of the table to pmu-events.c so it may be hidden. By
abstracting the table the implementation can later be changed.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Stephane Eranian 
Cc: Will Deacon 
Cc: Xing Zhengjun 
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220812230949.683239-8-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf pmu-events: Avoid passing pmu_events_map

2022-08-13T18:00:32+00:00

Preparation for hiding pmu_events_map as an implementation detail. While
the map is passed, the table of events is all that is normally wanted.

While modifying the function's types, rename pmu_events_map__find to
pmu_events_table__find to match later encapsulation. Similarly rename
pmu_add_cpu_aliases_map to pmu_add_cpu_aliases_table.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Stephane Eranian 
Cc: Will Deacon 
Cc: Xing Zhengjun 
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220812230949.683239-7-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf pmu-events: Hide pmu_sys_event_tables

2022-08-13T18:00:16+00:00

Move usage of the table to pmu-events.c so it may be hidden. By
abstracting the table the implementation can later be changed.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Stephane Eranian 
Cc: Will Deacon 
Cc: Xing Zhengjun 
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220812230949.683239-6-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo