gprofng/testsuite/gprofng.display/synprog/pagethrash.c

   1 /* Copyright (C) 2021-2023 Free Software Foundation, Inc.
   2    Contributed by Oracle.
   3
   4    This file is part of GNU Binutils.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3, or (at your option)
   9    any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, 51 Franklin Street - Fifth Floor, Boston,
  19    MA 02110-1301, USA.  */
  20
  21 #include <unistd.h>
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include "stopwatch.h"
  25
  26 /*=======================================================*/
  27
  28 /* pagethrash - allocate some memory, and thrash around in it */
  29 int
  30 pagethrash (int thrashmb)
  31 {
  32   char buf[1024];
  33
  34   hrtime_t start = gethrtime ();
  35   hrtime_t vstart = gethrvtime ();
  36
  37   /* Log the event */
  38   wlog ("start of pagethrash", NULL);
  39
  40   /* Start a stopwatch */
  41   stopwatch_t *w = stpwtch_alloc ("pagethrash", 0);
  42
  43   /* compute the size */
  44   unsigned long size = thrashmb * 1024 * 1024;
  45   int pagesize = getpagesize ();
  46   void *space = malloc (size + pagesize);
  47   if (space == NULL)
  48     {
  49       fprintf (stderr, "\tpagethrash failed; can't get %ld bytes.\n", size);
  50       exit (1);
  51     }
  52
  53   /* round address to page boundary */
  54   unsigned long loc = (((unsigned long) space + pagesize - 1) & ~(pagesize - 1));
  55   long npages = size / pagesize;
  56
  57   /* touch all the pages to force them in */
  58   for (long i = 0; i < npages; i++)
  59     {
  60       stpwtch_start (w);
  61       *(int *) (loc + i * pagesize) = i;
  62       stpwtch_stop (w);
  63     }
  64
  65   /* now free up the space */
  66   free (space);
  67
  68   /* print the timing results */
  69   stpwtch_print (w);
  70   free ((void *) w);
  71
  72   sprintf (buf, "pagethrash: %ld pages", npages);
  73   whrvlog (gethrtime () - start, gethrvtime () - vstart, buf, NULL);
  74   return 0;
  75 }