Switch to new np-section protocol.

Everything is in one 32-bit word now.

1 files changed, 12 insertions, 3 deletions

diff --git a/src/kernel_iface.c b/src/kernel_iface.c
index 1426795..33d56df 100644
--- a/src/kernel_iface.c
+++ b/src/kernel_iface.c
@@ -43,6 +43,8 @@ int init_kernel_iface(void)
         int err = 0;
         long page_size = sysconf(_SC_PAGESIZE);
 
+        BUILD_BUG_ON(sizeof(union np_flag) != sizeof(uint32_t));
+
         err = map_file(LITMUS_CTRL_DEVICE, (void**) &ctrl_page, CTRL_PAGES * page_size);
         if (err) {
                 fprintf(stderr, "%s: cannot open LITMUS^RT control page (%m)\n",
@@ -55,7 +57,7 @@ int init_kernel_iface(void)
 void enter_np(void)
 {
         if (likely(ctrl_page != NULL) || init_kernel_iface() == 0)
-                ctrl_page->np_flag++;
+                ctrl_page->sched.np.flag++;
         else
                 fprintf(stderr, "enter_np: control page not mapped!\n");
 }
@@ -63,14 +65,21 @@ void enter_np(void)
 
 void exit_np(void)
 {
-        if (likely(ctrl_page != NULL) && --ctrl_page->np_flag == 0) {
+        if (likely(ctrl_page != NULL) &&
+            ctrl_page->sched.np.flag &&
+            !(--ctrl_page->sched.np.flag)) {
                 /* became preemptive, let's check for delayed preemptions */
                 __sync_synchronize();
-                if (ctrl_page->delayed_preemption)
+                if (ctrl_page->sched.np.preempt)
                         sched_yield();
         }
 }
 
+int requested_to_preempt(void)
+{
+        return (likely(ctrl_page != NULL) && ctrl_page->sched.np.preempt);
+}
+
 /* init and return a ptr to the control page for
  * preemption and migration overhead analysis
  *