process: changes for IRQ when swapping

Don't scribble on the udata when it is unsafe
Don't charge time to processes when swapping them

diff --git a/Kernel/process.c b/Kernel/process.c
index 77d2c53..3b10320 100644 (file)
--- a/Kernel/process.c
+++ b/Kernel/process.c
@@ -331,8 +331,10 @@ void load_average(void)
 
 void timer_interrupt(void)
 {
-       /* Increment processes and global tick counters */
-       if (udata.u_ptab->p_status == P_RUNNING) {
+       /* Increment processes and global tick counters. We can't do this
+          mid swap because we might have half of the bits for one process
+          and half of another.. */
+       if (!inswap && udata.u_ptab->p_status == P_RUNNING) {
                if (udata.u_insys)
                        udata.u_stime++;
                else
@@ -368,10 +370,10 @@ void timer_interrupt(void)
 #endif
        }
 #ifndef CONFIG_SINGLETASK
-       /* Check run time of current process */
-        /* Time to switch out? */
-        /* FIXME: don't count runticks while swapping in ! */
-       if ((++runticks >= udata.u_ptab->p_priority)
+       /* Check run time of current process. We don't charge time while
+          swapping as the last thing we want to do is to swap a process in
+          and decide it took time to swap in so needs to go away again! */
+       if (!inswap && (++runticks >= udata.u_ptab->p_priority)
            && !udata.u_insys && inint && nready > 1) {
                  need_resched = 1;
 #ifdef DEBUG_PREEMPT