linux.git/tools/perf/util/parse-events.c, branch v6.17

perf tp_pmu: Factor existing tracepoint logic to new file

2025-07-26T23:31:43+00:00

Start the creation of a tracepoint PMU abstraction. Tracepoint events
don't follow the regular sysfs perf conventions. Eventually the new
PMU abstraction will bridge the gap so tracepoint events look more
like regular perf ones.

Signed-off-by: Ian Rogers 
Tested-by: Arnaldo Carvalho de Melo 
Link: https://lore.kernel.org/r/20250725185202.68671-5-irogers@google.com
Signed-off-by: Namhyung Kim

perf parse-events: Remove non-json software events

2025-07-26T23:31:43+00:00

Remove the hard coded encodings from parse-events. This has the
consequence that software events are matched using the sysfs/json
priority, will be case insensitive and will be wildcarded across PMUs.
As there were software and hardware types in the parsing code, the
removal means software vs hardware logic can be removed and hardware
assumed.

Now the perf json provides detailed descriptions of software events,
remove the previous listing support that didn't contain event
descriptions. When globbing is required for the "sw" option in perf
list, use string PMU globbing as was done previously for the tool PMU.

The output of `perf list sw` command changed like this.

Before:
  List of pre-defined events (to be used in -e or -M):

    alignment-faults                                   [Software event]
    bpf-output                                         [Software event]
    cgroup-switches                                    [Software event]
    context-switches OR cs                             [Software event]
    cpu-clock                                          [Software event]
    cpu-migrations OR migrations                       [Software event]
    dummy                                              [Software event]
    emulation-faults                                   [Software event]
    major-faults                                       [Software event]
    minor-faults                                       [Software event]
    page-faults OR faults                              [Software event]
    task-clock                                         [Software event]

After:
  List of pre-defined events (to be used in -e or -M):

  software:
    alignment-faults
         [Number of kernel handled memory alignment faults. Unit: software]
    bpf-output
         [An event used by BPF programs to write to the perf ring buffer. Unit: software]
    cgroup-switches
         [Number of context switches to a task in a different cgroup. Unit: software]
    context-switches
         [Number of context switches [This event is an alias of cs]. Unit: software]
    cpu-clock
         [Per-CPU high-resolution timer based event. Unit: software]
    cpu-migrations
         [Number of times a process has migrated to a new CPU [This event is an alias of migrations]. Unit: software]
    cs
         [Number of context switches [This event is an alias of context-switches]. Unit: software]
    dummy
         [A placeholder event that doesn't count anything. Unit: software]
    ...

Signed-off-by: Ian Rogers 
Tested-by: Arnaldo Carvalho de Melo 
Link: https://lore.kernel.org/r/20250725185202.68671-4-irogers@google.com
Signed-off-by: Namhyung Kim

perf parse-events: Fix missing slots for Intel topdown metric events

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

Topdown metric events require grouping with a slots event. In perf
metrics this is currently achieved by metrics adding an unnecessary
"0 * tma_info_thread_slots". New TMA metrics trigger optimizations of
the metric expression that removes the event and breaks the metric due
to the missing but required event. Add a pass immediately before
sorting and fixing parsed events, that insert a slots event if one is
missing. Update test expectations to match this.

Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250719030517.1990983-15-irogers@google.com
Signed-off-by: Namhyung Kim

perf parse-events: Support user CPUs mixed with threads/processes

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

Counting events system-wide with a specified CPU prior to this change
worked:
```
$ perf stat -e 'msr/tsc/,msr/tsc,cpu=cpu_core/,msr/tsc,cpu=cpu_atom/' -a sleep 1

  Performance counter stats for 'system wide':

     59,393,419,099      msr/tsc/
     33,927,965,927      msr/tsc,cpu=cpu_core/
     25,465,608,044      msr/tsc,cpu=cpu_atom/
```

However, when counting with process the counts became system wide:
```
$ perf stat -e 'msr/tsc/,msr/tsc,cpu=cpu_core/,msr/tsc,cpu=cpu_atom/' perf test -F 10
 10.1: Basic parsing test                                            : Ok
 10.2: Parsing without PMU name                                      : Ok
 10.3: Parsing with PMU name                                         : Ok

 Performance counter stats for 'perf test -F 10':

        59,233,549      msr/tsc/
        59,227,556      msr/tsc,cpu=cpu_core/
        59,224,053      msr/tsc,cpu=cpu_atom/
```

Make the handling of CPU maps with event parsing clearer. When an
event is parsed creating an evsel the cpus should be either the PMU's
cpumask or user specified CPUs.

Update perf_evlist__propagate_maps so that it doesn't clobber the user
specified CPUs. Try to make the behavior clearer, firstly fix up
missing cpumasks. Next, perform sanity checks and adjustments from the
global evlist CPU requests and for the PMU including simplifying to
the "any CPU"(-1) value. Finally remove the event if the cpumask is
empty.

So that events are opened with a CPU and a thread change stat's
create_perf_stat_counter to give both.

With the change things are fixed:
```
$ perf stat --no-scale -e 'msr/tsc/,msr/tsc,cpu=cpu_core/,msr/tsc,cpu=cpu_atom/' perf test -F 10
 10.1: Basic parsing test                                            : Ok
 10.2: Parsing without PMU name                                      : Ok
 10.3: Parsing with PMU name                                         : Ok

 Performance counter stats for 'perf test -F 10':

        63,704,975      msr/tsc/
        47,060,704      msr/tsc,cpu=cpu_core/                        (4.62%)
        16,640,591      msr/tsc,cpu=cpu_atom/                        (2.18%)
```

However, note the "--no-scale" option is used. This is necessary as
the running time for the event on the counter isn't the same as the
enabled time because the thread doesn't necessarily run on the CPUs
specified for the counter. All counter values are scaled with:

  scaled_value = value * time_enabled / time_running

and so without --no-scale the scaled_value becomes very large. This
problem already exists on hybrid systems for the same reason. Here are
2 runs of the same code with an instructions event that counts the
same on both types of core, there is no real multiplexing happening on
the event:

```
$ perf stat -e instructions perf test -F 10
...
 Performance counter stats for 'perf test -F 10':

        87,896,447      cpu_atom/instructions/                       (14.37%)
        98,171,964      cpu_core/instructions/                       (85.63%)
...
$ perf stat --no-scale -e instructions perf test -F 10
...
 Performance counter stats for 'perf test -F 10':

        13,069,890      cpu_atom/instructions/                       (19.32%)
        83,460,274      cpu_core/instructions/                       (80.68%)
...
```
The scaling has inflated per-PMU instruction counts and the overall
count by 2x.

To fix this the kernel needs changing when a task+CPU event (or just
task event on hybrid) is scheduled out. A fix could be that the state
isn't inactive but off for such events, so that time_enabled counts
don't accumulate on them.

Reviewed-by: Thomas Falcon 
Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250719030517.1990983-13-irogers@google.com
Signed-off-by: Namhyung Kim

perf parse-events: Minor __add_event refactoring

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

Rename cpu_list to user_cpus. If a PMU isn't given, find it early from
the perf_event_attr. Make the pmu_cpus more explicitly a copy from the
PMU (except when user_cpus are given). Derive the cpus from pmu_cpus
and user_cpus as appropriate. Handle strdup errors on name and
metric_id.

Reviewed-by: Thomas Falcon 
Signed-off-by: Ian Rogers 
Tested-by: James Clark 
Link: https://lore.kernel.org/r/20250719030517.1990983-11-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 parse-events: Allow the cpu term to be a PMU or CPU range

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

On hybrid systems, events like msr/tsc/ will aggregate counts across
all CPUs. Often metrics only want a value like msr/tsc/ for the cores
on which the metric is being computed. Listing each CPU with terms
cpu=0,cpu=1.. is laborious and would need to be encoded for all
variations of a CPU model.

Allow the cpumask from a PMU to be an argument to the cpu term. For
example in the following the cpumask of the cstate_pkg PMU selects the
CPUs to count msr/tsc/ counter upon:
```
$ cat /sys/bus/event_source/devices/cstate_pkg/cpumask
0
$ perf stat -A -e 'msr/tsc,cpu=cstate_pkg/' -a sleep 0.1

 Performance counter stats for 'system wide':

CPU0          252,621,253      msr/tsc,cpu=cstate_pkg/

       0.101184092 seconds time elapsed
```

As the cpu term is now also allowed to be a string, allow it to encode
a range of CPUs (a list can't be supported as ',' is already a special
token).

The "event qualifiers" section of the `perf list` man page is updated
to detail the additional behavior.  The man page formatting is tidied
up in this section, as it was incorrectly appearing within the
"parameterized events" section.

Reviewed-by: Thomas Falcon 
Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250719030517.1990983-5-irogers@google.com
Signed-off-by: Namhyung Kim

perf parse-events: Warn if a cpu term is unsupported by a CPU

2025-07-24T20:41:34+00:00

Factor requested CPU warning out of evlist and into evsel. At the end
of adding an event, perform the warning check. To avoid repeatedly
testing if the cpu_list is empty, add a local variable.

```
$ perf stat -e cpu_atom/cycles,cpu=1/ -a true
WARNING: A requested CPU in '1' is not supported by PMU 'cpu_atom' (CPUs 16-27) for event 'cpu_atom/cycles/'

 Performance counter stats for 'system wide':

         cpu_atom/cycles/

       0.000781511 seconds time elapsed
```

Reviewed-by: Thomas Falcon 
Signed-off-by: Ian Rogers 
Tested-by: James Clark 
Link: https://lore.kernel.org/r/20250719030517.1990983-2-irogers@google.com
Signed-off-by: Namhyung Kim

perf parse-events: Minor tidy up of event_type helper

2025-07-11T19:36:40+00:00

Add missing breakpoint and raw types. Avoid a switch, just use a
lookup array. Switch the type to unsigned to avoid checking negative
values.

Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250710235126.1086011-3-irogers@google.com
Signed-off-by: Namhyung Kim

perf parse-events: Avoid scanning PMUs that can't contain events

2025-06-25T18:12:35+00:00

Add perf_pmus__scan_for_event that only reads sysfs for pmus that
could contain a given event.

Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250624231837.179536-2-irogers@google.com
Signed-off-by: Namhyung Kim