2 dnl # 2.6.24 API change
3 dnl # Empty write barriers are now supported and we should use them.
5 AC_DEFUN([ZFS_AC_KERNEL_BIO_EMPTY_BARRIER], [
6 AC_MSG_CHECKING([whether bio_empty_barrier() is defined])
7 ZFS_LINUX_TRY_COMPILE([
11 (void)bio_empty_barrier(&bio);
14 AC_DEFINE(HAVE_BIO_EMPTY_BARRIER, 1,
15 [bio_empy_barrier() is defined])