1 files changed, 13 insertions, 1 deletions
diff --git a/libev.m4 b/libev.m4
index 393835e..2ba20eb 100644
--- a/libev.m4
+++ b/libev.m4
@@ -7,7 +7,19 @@ AC_CHECK_HEADERS(sys/inotify.h sys/epoll.h sys/event.h sys/queue.h port.h poll.h
 AC_CHECK_FUNCS(inotify_init epoll_ctl kqueue port_create poll select eventfd)
  
 AC_CHECK_FUNC(clock_gettime, [], [ 
-   if test -z "$LIBEV_M4_AVOID_LIBRT"; then
+   dnl on linux, try syscall wrapper first
+   if test $(uname) = Linux; then
+      AC_MSG_CHECKING(for clock_gettime syscall)
+      AC_LINK_IFELSE([AC_LANG_PROGRAM(
+                      [#include <syscall.h>
+                       #include <time.h>],
+                      [struct timespec ts; int status = syscall (SYS_clock_gettime, CLOCK_REALTIME, &ts)])],
+                     [ac_have_clock_syscall=1
+                      AC_DEFINE(HAVE_CLOCK_SYSCALL, 1, "use syscall interface for clock_gettime")
+                      AC_MSG_RESULT(yes)],
+                     [AC_MSG_RESULT(no)])
+   fi
+   if test -z "$LIBEV_M4_AVOID_LIBRT" && test -z "$ac_have_clock_syscall"; then
       AC_CHECK_LIB(rt, clock_gettime) 
       unset ac_cv_func_clock_gettime
       AC_CHECK_FUNCS(clock_gettime)