Changes in kernel/generic/src/proc/scheduler.c [1ba37fa:481d4751] in mainline

File:

• kernel/generic/src/proc/scheduler.c (modified) (6 diffs)

kernel/generic/src/proc/scheduler.c

@@ -1 +1 @@
 /*
- * Copyright (c) 2001-2007 Jakub Jermar
+ * Copyright (c) 2010 Jakub Jermar
  * All rights reserved.
  *
@@ -187 +187 @@
 
 loop:
-        interrupts_enable();
         
         if (atomic_get(&CPU->nrdy) == 0) {
@@ -196 +195 @@
                  */
 
-                /*
+                 /* Mark CPU as it was idle this clock tick */
+                 spinlock_lock(&CPU->lock);
+                 CPU->idle = true;
+                 spinlock_unlock(&CPU->lock);
+
+                 interrupts_enable();
+                 /*
                  * An interrupt might occur right now and wake up a thread.
                  * In such case, the CPU will continue to go to sleep
                  * even though there is a runnable thread.
                  */
-
-                 spinlock_lock(&CPU->lock);
-                 CPU->idle = true;
-                 spinlock_unlock(&CPU->lock);
                  cpu_sleep();
+                 interrupts_disable();
                  goto loop;
         }
-
-        interrupts_disable();
         
         for (i = 0; i < RQ_COUNT; i++) {
@@ -382 +382 @@
         int priority;
         DEADLOCK_PROBE_INIT(p_joinwq);
+        task_t *old_task = TASK;
+        as_t *old_as = AS;
 
         ASSERT(CPU != NULL);
         
+        /*
+         * Hold the current task and the address space to prevent their
+         * possible destruction should thread_destroy() be called on this or any
+         * other processor while the scheduler is still using them.
+         */
+        if (old_task)
+                task_hold(old_task);
+        if (old_as)
+                as_hold(old_as);
+
         if (THREAD) {
                 /* must be run after the switch to scheduler stack */
@@ -476 +488 @@
          */
         if (TASK != THREAD->task) {
-                as_t *as1 = NULL;
-                as_t *as2;
-
-                if (TASK) {
-                        spinlock_lock(&TASK->lock);
-                        as1 = TASK->as;
-                        spinlock_unlock(&TASK->lock);
-                }
-
-                spinlock_lock(&THREAD->task->lock);
-                as2 = THREAD->task->as;
-                spinlock_unlock(&THREAD->task->lock);
+                as_t *new_as = THREAD->task->as;
                 
                 /*
@@ -493 +494 @@
                  * space.
                  */
-                if (as1 != as2) {
+                if (old_as != new_as) {
                         /*
                          * Both tasks and address spaces are different.
                          * Replace the old one with the new one.
                          */
-                        as_switch(as1, as2);
+                        as_switch(old_as, new_as);
                 }
+
                 TASK = THREAD->task;
                 before_task_runs();
         }
 
+        if (old_task)
+                task_release(old_task);
+        if (old_as)
+                as_release(old_as);
+        
         spinlock_lock(&THREAD->lock);   
         THREAD->state = Running;