--- libeio/libeio.m4	2011/07/07 22:37:11	1.15
+++ libeio/libeio.m4	2011/07/24 03:32:54	1.16
@@ -1,6 +1,6 @@
 dnl openbsd in it's neverending brokenness requires stdint.h for intptr_t,
 dnl but that header isn't very portable...
-AC_CHECK_HEADERS([stdint.h])
+AC_CHECK_HEADERS([stdint.h sys/syscall.h])
 
 AC_SEARCH_LIBS(
    pthread_create,
@@ -138,6 +138,16 @@
 ],ac_cv_fallocate=yes,ac_cv_fallocate=no)])
 test $ac_cv_fallocate = yes && AC_DEFINE(HAVE_FALLOCATE, 1, fallocate(2) is available)
 
+AC_CACHE_CHECK(for sys_syncfs, ac_cv_sys_syncfs, [AC_LINK_IFELSE([
+#include <unistd.h>
+#include <sys/syscall.h>
+int main (void)
+{
+  int res = syscall (__NR_syncfs, (int)0);
+}
+],ac_cv_sys_syncfs=yes,ac_cv_sys_syncfs=no)])
+test $ac_cv_sys_syncfs = yes && AC_DEFINE(HAVE_SYS_SYNCFS, 1, syscall(__NR_syncfs) is available)
+
 dnl #############################################################################
 dnl # these checks exist for the benefit of IO::AIO