tools/perf/arch/x86/util/evlist.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <string.h>
   3 #include "../../../util/evlist.h"
   4 #include "../../../util/evsel.h"
   5 #include "topdown.h"
   6 #include "evsel.h"
   7
   8 int arch_evlist__cmp(const struct evsel *lhs, const struct evsel *rhs)
   9 {
  10         /*
  11          * Currently the following topdown events sequence are supported to
  12          * move and regroup correctly.
  13          *
  14          * a. all events in a group
  15          *    perf stat -e "{instructions,topdown-retiring,slots}" -C0 sleep 1
  16          *    WARNING: events were regrouped to match PMUs
  17          *     Performance counter stats for 'CPU(s) 0':
  18          *          15,066,240     slots
  19          *          1,899,760      instructions
  20          *          2,126,998      topdown-retiring
  21          * b. all events not in a group
  22          *    perf stat -e "instructions,topdown-retiring,slots" -C0 sleep 1
  23          *    WARNING: events were regrouped to match PMUs
  24          *     Performance counter stats for 'CPU(s) 0':
  25          *          2,045,561      instructions
  26          *          17,108,370     slots
  27          *          2,281,116      topdown-retiring
  28          * c. slots event in a group but topdown metrics events outside the group
  29          *    perf stat -e "{instructions,slots},topdown-retiring" -C0 sleep 1
  30          *    WARNING: events were regrouped to match PMUs
  31          *     Performance counter stats for 'CPU(s) 0':
  32          *         20,323,878      slots
  33          *          2,634,884      instructions
  34          *          3,028,656      topdown-retiring
  35          * d. slots event and topdown metrics events in two groups
  36          *    perf stat -e "{instructions,slots},{topdown-retiring}" -C0 sleep 1
  37          *    WARNING: events were regrouped to match PMUs
  38          *     Performance counter stats for 'CPU(s) 0':
  39          *         26,319,024      slots
  40          *          2,427,791      instructions
  41          *          2,683,508      topdown-retiring
  42          *
  43          * If slots event and topdown metrics events are not in same group, the
  44          * topdown metrics events must be first event after the slots event group,
  45          * otherwise topdown metrics events can't be regrouped correctly, e.g.
  46          *
  47          * a. perf stat -e "{instructions,slots},cycles,topdown-retiring" -C0 sleep 1
  48          *    WARNING: events were regrouped to match PMUs
  49          *     Performance counter stats for 'CPU(s) 0':
  50          *         17,923,134      slots
  51          *          2,154,855      instructions
  52          *          3,015,058      cycles
  53          *    <not supported>      topdown-retiring
  54          *
  55          * If slots event and topdown metrics events are in two groups, the group which
  56          * has topdown metrics events must contain only the topdown metrics event,
  57          * otherwise topdown metrics event can't be regrouped correctly as well, e.g.
  58          *
  59          * a. perf stat -e "{instructions,slots},{topdown-retiring,cycles}" -C0 sleep 1
  60          *    WARNING: events were regrouped to match PMUs
  61          *    Error:
  62          *    The sys_perf_event_open() syscall returned with 22 (Invalid argument) for
  63          *    event (topdown-retiring)
  64          */
  65         if (topdown_sys_has_perf_metrics() &&
  66             (arch_evsel__must_be_in_group(lhs) || arch_evsel__must_be_in_group(rhs))) {
  67                 /* Ensure the topdown slots comes first. */
  68                 if (arch_is_topdown_slots(lhs))
  69                         return -1;
  70                 if (arch_is_topdown_slots(rhs))
  71                         return 1;
  72
  73                 /*
  74                  * Move topdown metrics events forward only when topdown metrics
  75                  * events are not in same group with previous slots event. If
  76                  * topdown metrics events are already in same group with slots
  77                  * event, do nothing.
  78                  */
  79                 if (arch_is_topdown_metrics(lhs) && !arch_is_topdown_metrics(rhs) &&
  80                     lhs->core.leader != rhs->core.leader)
  81                         return -1;
  82                 if (!arch_is_topdown_metrics(lhs) && arch_is_topdown_metrics(rhs) &&
  83                     lhs->core.leader != rhs->core.leader)
  84                         return 1;
  85         }
  86
  87         /* Retire latency event should not be group leader*/
  88         if (lhs->retire_lat && !rhs->retire_lat)
  89                 return 1;
  90         if (!lhs->retire_lat && rhs->retire_lat)
  91                 return -1;
  92
  93         /* Default ordering by insertion index. */
  94         return lhs->core.idx - rhs->core.idx;
  95 }