[SQUASH ME] Another intermediate commit

kernel/exit.c

@@ -772,6 +772,29 @@ void __noreturn do_exit(long code)
 
 	rq = this_rq();
 
+	/**
+	 * BEWARE:
+	 * We want to update the plan runtime model not too early to ensure that the exiting process
+	 * has already signaled its exit to its parents otherwise the scheduler could switch the
+	 * process to early to the parent which itself is waiting for the child to exit which leads to
+	 * a deadlock!
+	 * But we also do not want to update it too late since then the model would not be up to date
+	 * when the next task should be picked and therefore the child would remain the current process
+	 * of the model which also would lead to a deadlock since the child will never be replaced by
+	 * the runnable parent.
+	 * We want to update the model exactly after the childs exit-signal is sent to the parent.
+	 */
+	// prevent syscalls from outside of the measured program (e.g. admin tasks) to be recognized
+	if (PB_EXEC_MODE == rq->pb.mode) {
+		printk(KERN_WARNING "TASK DEAD: %u\n", tsk->pid);
+		// inform the pb-scheduler knows which syscall triggered the scheduling
+		rq->pb.triggering_syscall.type = sched_trig_EXIT;
+		rq->pb.triggering_syscall.origin = current;
+
+		// inform the plan runtime state
+		plan_rt_state_incr_num_exited_procs();
+	}
+
 	// call the readout before the process is terminated
 	if (is_relevant_process(tsk)) {
 		pbm_exit(tsk->pid, tsk->real_parent->pid);
@@ -910,29 +933,6 @@ void __noreturn do_exit(long code)
 	TASKS_RCU(preempt_enable());
 	exit_notify(tsk, group_dead);
 
-	/**
-	 * BEWARE:
-	 * We want to update the plan runtime model not too early to ensure that the exiting process
-	 * has already signaled its exit to its parents otherwise the scheduler could switch the
-	 * process to early to the parent which itself is waiting for the child to exit which leads to
-	 * a deadlock!
-	 * But we also do not want to update it too late since then the model would not be up to date
-	 * when the next task should be picked and therefore the child would remain the current process
-	 * of the model which also would lead to a deadlock since the child will never be replaced by
-	 * the runnable parent.
-	 * We want to update the model exactly after the childs exit-signal is sent to the parent.
-	 */
-	// prevent syscalls from outside of the measured program (e.g. admin tasks) to be recognized
-	if (PB_EXEC_MODE == rq->pb.mode) {
-		printk(KERN_WARNING "TASK DEAD: %u\n", tsk->pid);
-		// inform the pb-scheduler knows which syscall triggered the scheduling
-		rq->pb.triggering_syscall.type = sched_trig_EXIT;
-		rq->pb.triggering_syscall.origin = current;
-
-		// inform the plan runtime state
-		plan_rt_state_incr_num_exited_procs();
-	}
-
 	proc_exit_connector(tsk);
 	mpol_put_task_policy(tsk);
 #ifdef CONFIG_FUTEX

kernel/sched/pb.c

@@ -294,6 +294,7 @@ static void dequeue_task_pb(struct rq *rq, struct task_struct *p, int flags)
 	printk("Dequeue task: %u\n", p->pid);
 
 	if (pb->waiting_on_io) {
+		printk("Waiting for IO\n", p->pid);
 		return;
 	}
 	pb->waiting_on_io = 1;
@@ -307,6 +308,7 @@ static void dequeue_task_pb(struct rq *rq, struct task_struct *p, int flags)
 		printk("WARNING: PERF EVENT IS NULL");
 	}
 
+	printk(KERN_WARNING Bold Red "EXIT? %i" End "\n", pb->triggering_syscall.type);
 	if (pb->triggering_syscall.type == sched_trig_EXIT) {
 		printk(KERN_WARNING Bold Red "EXIT TRIGGERED THIS!!!" End "\n");
 		// remove the exited process from the stack and run the next available

pb_utils/create_image.sh

 #!/bin/bash
 IMG=build/qemu-image.img
 DIR=build/mount-point.dir
+KEYRING=build/debian-keyring.gpg
 DEBIAN_VERSION=jessie
 DEBOOTSTRAP_FOLDER=$PWD/build/debootstrap
 DEBOOTSTRAP_SOURCE=https://deb.debian.org/debian/pool/main/d/debootstrap
 MIRROR=https://archive.debian.org/debian-archive/debian
 
 # get dbootstrap
-if [ ! -d $DEBOOTSTRAP_FOLDER ]
-then
+if [ ! -d $DEBOOTSTRAP_FOLDER ]; then
     mkdir -p $DEBOOTSTRAP_FOLDER
     # get versions sorted ascendingly by last modification (?C=M;O=A supported by apache servers
     # which makes something like sort -V unnecessary which also can not take the modification date

pb_utils/pb_submitter/test_prog.c

@@ -10,23 +10,36 @@ int main(void)
     // Creating first child
     pid_t n1 = fork();
 
-    if (n1 > 0)
-    {
-        fprintf(stderr, "Parent %d of %d\n", getpid(), n1);
+    // Creating second child. First child
+    // also executes this line and creates
+    // grandchild.
+    pid_t n2 = fork();
 
     // barrier: make all fathers wait for all its child processes (since all processes use that line)
-        while ((wpid = wait(&status)) > 0) {fprintf(stderr, "%d waiting...\n", getpid());};
+    while ((wpid = wait(&status)) > 0) {};
+
+    if (n1 > 0 && n2 > 0)
+    {
+        fprintf(stderr, "Parent %d of %d %d\n", getpid(), n1, n2);
 
         // check if program runs && syscall to switch tasks
         fprintf(stderr, "run completed\n");
-        // TODO WHY IS THIS NECESSARY?!
         usleep(1);
     }
-    else
+    else if (n1 == 0 && n2 > 0)
     {
         // set a different process name (comm) for the child to differentiate it from the parent
-        prctl(PR_SET_NAME, "test_child");
-        fprintf(stderr, "Child %d of %d\n", getpid(), n1);
+        prctl(PR_SET_NAME, "test_child_1");
+        fprintf(stderr, "First child %d of %d %d\n", getpid(), n1, n2);
+    }
+    else if (n1 > 0 && n2 == 0)
+    {
+        prctl(PR_SET_NAME, "test_child_2");
+        fprintf(stderr, "Second child %d of %d %d\n", getpid(), n1, n2);
+    }
+    else {
+        prctl(PR_SET_NAME, "test_child_3");
+        fprintf(stderr, "Third child %d of %d %d\n", getpid(), n1, n2);
     }
     return 0;
 }
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