/* Copyright (C) 2007-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>

#include <sys/mman.h>

int

posix_madvise (void *addr, size_t len, int advice)

{

  /* We have one problem: the kernel's MADV_DONTNEED does not

     correspond to POSIX's POSIX_MADV_DONTNEED.  The former simply

     discards changes made to the memory without writing it back to

     disk, if this would be necessary.  The POSIX behavior does not

     allow this.  There is no functionality mapping the POSIX behavior

     so far so we ignore that advice for now.  */

  if (advice == POSIX_MADV_DONTNEED)

    return 0;

  INTERNAL_SYSCALL_DECL (err);

  int result = INTERNAL_SYSCALL (madvise, err, 3, addr, len, advice);

  return INTERNAL_SYSCALL_ERRNO (result, err);

}