This change is intended to be a no-op for most current cases, the
default sort order is the order the events were parsed. Where it
varies is in how groups are handled. Previously an uncore and core
event that are grouped would most often cause the group to be removed:
```
$ perf stat -e '{instructions,uncore_imc_free_running_0/data_total/}' -a sleep 1
WARNING: grouped events cpus do not match, disabling group:
anon group { instructions, uncore_imc_free_running_0/data_total/ }
...
```
However, when wildcards are used the events should be re-sorted and
re-grouped in parse_events__set_leader, but this currently fails for
simple examples:
```
$ perf stat -e '{uncore_imc_free_running/data_read/,uncore_imc_free_running/data_write/}' -a sleep 1
Performance counter stats for 'system wide':
<not counted> MiB uncore_imc_free_running/data_read/
<not counted> MiB uncore_imc_free_running/data_write/
1.000996992 seconds time elapsed
```
A futher failure mode, fixed in this patch, is to force topdown events
into a group.
This change moves sorting the evsels in the evlist after parsing. It
requires parsing to set up groups. First the evsels are sorted
respecting the existing groupings and parse order, but also reordering
to ensure evsels of the same PMU and group appear together. So that
software and aux events respect groups, their pmu_name is taken from
the group leader. The sorting is done with list_sort removing a memory
allocation.
After sorting a pass is done to correct the group leaders and for
topdown events ensuring they have a group leader.
This fixes the problems seen before:
```
$ perf stat -e '{uncore_imc_free_running/data_read/,uncore_imc_free_running/data_write/}' -a sleep 1
Performance counter stats for 'system wide':
727.42 MiB uncore_imc_free_running/data_read/
81.84 MiB uncore_imc_free_running/data_write/
1.000948615 seconds time elapsed
```
As well as making groups not fail for cases like:
```
$ perf stat -e '{imc_free_running_0/data_total/,imc_free_running_1/data_total/}' -a sleep 1
Performance counter stats for 'system wide':
256.47 MiB imc_free_running_0/data_total/
256.48 MiB imc_free_running_1/data_total/
1.001165442 seconds time elapsed
```
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Florian Fischer <florian.fischer@muhq.space>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Steinar H. Gunderson <sesse@google.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20230312021543.3060328-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
347c2f0a09