kernel/tools/testing/selftests/powerpc/pmu/ebb/task_event_vs_ebb_test.c

   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 per-task event vs an EBB - in that order. The EBB should push the
  19  * per-task event off the PMU.
  20  */
  21
  22 static 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.exclude_kernel = 1;
  27         event->attr.exclude_hv = 1;
  28         event->attr.exclude_idle = 1;
  29
  30         FAIL_IF(event_open_with_pid(event, child_pid));
  31         FAIL_IF(event_enable(event));
  32
  33         return 0;
  34 }
  35
  36 int task_event_vs_ebb(void)
  37 {
  38         union pipe read_pipe, write_pipe;
  39         struct event event;
  40         pid_t pid;
  41         int rc;
  42
  43         SKIP_IF(!ebb_is_supported());
  44
  45         FAIL_IF(pipe(read_pipe.fds) == -1);
  46         FAIL_IF(pipe(write_pipe.fds) == -1);
  47
  48         pid = fork();
  49         if (pid == 0) {
  50                 /* NB order of pipes looks reversed */
  51                 exit(ebb_child(write_pipe, read_pipe));
  52         }
  53
  54         /* We setup the task event first */
  55         rc = setup_child_event(&event, pid);
  56         if (rc) {
  57                 kill_child_and_wait(pid);
  58                 return rc;
  59         }
  60
  61         /* Signal the child to install its EBB event and wait */
  62         if (sync_with_child(read_pipe, write_pipe))
  63                 /* If it fails, wait for it to exit */
  64                 goto wait;
  65
  66         /* Signal the child to run */
  67         FAIL_IF(sync_with_child(read_pipe, write_pipe));
  68
  69 wait:
  70         /* The EBB event should push the task event off so the child should succeed */
  71         FAIL_IF(wait_for_child(pid));
  72         FAIL_IF(event_disable(&event));
  73         FAIL_IF(event_read(&event));
  74
  75         event_report(&event);
  76
  77         /* The task event may have run, or not so we can't assert anything about it */
  78
  79         return 0;
  80 }
  81
  82 int main(void)
  83 {
  84         return test_harness(task_event_vs_ebb, "task_event_vs_ebb");
  85 }