rt: Remove running_on flag. Does nothing

Author: brson

src/rt/rust_scheduler.cpp

@@ -282,9 +282,7 @@ rust_scheduler::start_main_loop() {
         DLOG(this, task,
              "Running task %p on worker %d",
              scheduled_task, id);
-        scheduled_task->running_on = id;
         activate(scheduled_task);
-        scheduled_task->running_on = -1;
 
         DLOG(this, task,
              "returned from task %s @0x%" PRIxPTR

src/rt/rust_task.cpp

@@ -244,7 +244,6 @@ rust_task::rust_task(rust_scheduler *sched, rust_task_list *state,
     list_index(-1),
     next_port_id(0),
     rendezvous_ptr(0),
-    running_on(-1),
     local_region(&sched->srv->local_region),
     boxed(&local_region),
     unwinding(false),
@@ -626,8 +625,7 @@ rust_task::backtrace() {
 
 bool rust_task::can_schedule(int id)
 {
-    return
-        running_on == -1;
+    return true;
 }
 
 void *

src/rt/rust_task.h

@@ -98,10 +98,6 @@ rust_task : public kernel_owned<rust_task>, rust_cond
     // that location before waking us up.
     uintptr_t* rendezvous_ptr;
 
-    // This flag indicates that a worker is either currently running the task
-    // or is about to run this task.
-    int running_on;
-
     memory_region local_region;
     boxed_region boxed;