kernel/tools/testing/selftests/powerpc/pmu/per_event_excludes.c

   1 /*
   2  * Copyright 2014, Michael Ellerman, IBM Corp.
   3  * Licensed under GPLv2.
   4  */
   5
   6 #define _GNU_SOURCE
   7
   8 #include <elf.h>
   9 #include <limits.h>
  10 #include <stdio.h>
  11 #include <stdbool.h>
  12 #include <string.h>
  13 #include <sys/prctl.h>
  14
  15 #include "event.h"
  16 #include "lib.h"
  17 #include "utils.h"
  18
  19 /*
  20  * Test that per-event excludes work.
  21  */
  22
  23 static int per_event_excludes(void)
  24 {
  25         struct event *e, events[4];
  26         char *platform;
  27         int i;
  28
  29         platform = (char *)get_auxv_entry(AT_BASE_PLATFORM);
  30         FAIL_IF(!platform);
  31         SKIP_IF(strcmp(platform, "power8") != 0);
  32
  33         /*
  34          * We need to create the events disabled, otherwise the running/enabled
  35          * counts don't match up.
  36          */
  37         e = &events[0];
  38         event_init_opts(e, PERF_COUNT_HW_INSTRUCTIONS,
  39                         PERF_TYPE_HARDWARE, "instructions");
  40         e->attr.disabled = 1;
  41
  42         e = &events[1];
  43         event_init_opts(e, PERF_COUNT_HW_INSTRUCTIONS,
  44                         PERF_TYPE_HARDWARE, "instructions(k)");
  45         e->attr.disabled = 1;
  46         e->attr.exclude_user = 1;
  47         e->attr.exclude_hv = 1;
  48
  49         e = &events[2];
  50         event_init_opts(e, PERF_COUNT_HW_INSTRUCTIONS,
  51                         PERF_TYPE_HARDWARE, "instructions(h)");
  52         e->attr.disabled = 1;
  53         e->attr.exclude_user = 1;
  54         e->attr.exclude_kernel = 1;
  55
  56         e = &events[3];
  57         event_init_opts(e, PERF_COUNT_HW_INSTRUCTIONS,
  58                         PERF_TYPE_HARDWARE, "instructions(u)");
  59         e->attr.disabled = 1;
  60         e->attr.exclude_hv = 1;
  61         e->attr.exclude_kernel = 1;
  62
  63         FAIL_IF(event_open(&events[0]));
  64
  65         /*
  66          * The open here will fail if we don't have per event exclude support,
  67          * because the second event has an incompatible set of exclude settings
  68          * and we're asking for the events to be in a group.
  69          */
  70         for (i = 1; i < 4; i++)
  71                 FAIL_IF(event_open_with_group(&events[i], events[0].fd));
  72
  73         /*
  74          * Even though the above will fail without per-event excludes we keep
  75          * testing in order to be thorough.
  76          */
  77         prctl(PR_TASK_PERF_EVENTS_ENABLE);
  78
  79         /* Spin for a while */
  80         for (i = 0; i < INT_MAX; i++)
  81                 asm volatile("" : : : "memory");
  82
  83         prctl(PR_TASK_PERF_EVENTS_DISABLE);
  84
  85         for (i = 0; i < 4; i++) {
  86                 FAIL_IF(event_read(&events[i]));
  87                 event_report(&events[i]);
  88         }
  89
  90         /*
  91          * We should see that all events have enabled == running. That
  92          * shows that they were all on the PMU at once.
  93          */
  94         for (i = 0; i < 4; i++)
  95                 FAIL_IF(events[i].result.running != events[i].result.enabled);
  96
  97         /*
  98          * We can also check that the result for instructions is >= all the
  99          * other counts. That's because it is counting all instructions while
 100          * the others are counting a subset.
 101          */
 102         for (i = 1; i < 4; i++)
 103                 FAIL_IF(events[0].result.value < events[i].result.value);
 104
 105         for (i = 0; i < 4; i++)
 106                 event_close(&events[i]);
 107
 108         return 0;
 109 }
 110
 111 int main(void)
 112 {
 113         return test_harness(per_event_excludes, "per_event_excludes");
 114 }