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1 files changed, 38 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/posix_madvise.c b/sysdeps/unix/sysv/linux/posix_madvise.c
new file mode 100644
index 0000000000..880b17ef31
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/posix_madvise.c
@@ -0,0 +1,38 @@
+/* Copyright (C) 2007 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#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);
+}