LXR linux/tools/testing/selftests/powerpc/pmu/ebb/task_event_pinned_vs_ebb

   1/*
   2 * Copyright 2014, Michael Ellerman, IBM Corp.
   3 * Licensed under GPLv2.
   4 */
   5
   6#include <signal.h>
   7#include <stdio.h>
   8#include <stdlib.h>
   9#include <stdbool.h>
  10#include <sys/types.h>
  11#include <sys/wait.h>
  12#include <unistd.h>
  13
  14#include "ebb.h"
  15
  16
  17/*
  18 * Tests a pinned per-task event vs an EBB - in that order. The pinned per-task
  19 * event should prevent the EBB event from being enabled.
  20 */
  21
  22static int setup_child_event(struct event *event, pid_t child_pid)
  23{
  24        event_init_named(event, 0x400FA, "PM_RUN_INST_CMPL");
  25
  26        event->attr.pinned = 1;
  27
  28        event->attr.exclude_kernel = 1;
  29        event->attr.exclude_hv = 1;
  30        event->attr.exclude_idle = 1;
  31
  32        FAIL_IF(event_open_with_pid(event, child_pid));
  33        FAIL_IF(event_enable(event));
  34
  35        return 0;
  36}
  37
  38int task_event_pinned_vs_ebb(void)
  39{
  40        union pipe read_pipe, write_pipe;
  41        struct event event;
  42        pid_t pid;
  43        int rc;
  44
  45        SKIP_IF(!ebb_is_supported());
  46
  47        FAIL_IF(pipe(read_pipe.fds) == -1);
  48        FAIL_IF(pipe(write_pipe.fds) == -1);
  49
  50        pid = fork();
  51        if (pid == 0) {
  52                /* NB order of pipes looks reversed */
  53                exit(ebb_child(write_pipe, read_pipe));
  54        }
  55
  56        /* We setup the task event first */
  57        rc = setup_child_event(&event, pid);
  58        if (rc) {
  59                kill_child_and_wait(pid);
  60                return rc;
  61        }
  62
  63        /* Signal the child to install its EBB event and wait */
  64        if (sync_with_child(read_pipe, write_pipe))
  65                /* If it fails, wait for it to exit */
  66                goto wait;
  67
  68        /* Signal the child to run */
  69        FAIL_IF(sync_with_child(read_pipe, write_pipe));
  70
  71wait:
  72        /* We expect it to fail to read the event */
  73        FAIL_IF(wait_for_child(pid) != 2);
  74        FAIL_IF(event_disable(&event));
  75        FAIL_IF(event_read(&event));
  76
  77        event_report(&event);
  78
  79        FAIL_IF(event.result.value == 0);
  80        /*
  81         * For reasons I don't understand enabled is usually just slightly
  82         * lower than running. Would be good to confirm why.
  83         */
  84        FAIL_IF(event.result.enabled == 0);
  85        FAIL_IF(event.result.running == 0);
  86
  87        return 0;
  88}
  89
  90int main(void)
  91{
  92        return test_harness(task_event_pinned_vs_ebb, "task_event_pinned_vs_ebb");
  93}
  94