X-Git-Url: http://akaros.cs.berkeley.edu/gitweb/?p=akaros.git;a=blobdiff_plain;f=kern%2Fsrc%2Fkthread.c;h=908a40ffd62c2e4d2783cabaf6798b8551bddec3;hp=518f37ab40958cf1a82ffcc926612e60f51f8672;hb=31e572ba36f16f7f17724bc3703977f6b9789d86;hpb=43bd877c94aea5e7686ca37eee8a36631b5b302d

diff --git a/kern/src/kthread.c b/kern/src/kthread.c
index 518f37a..908a40f 100644
--- a/kern/src/kthread.c
+++ b/kern/src/kthread.c
@@ -154,7 +154,13 @@ void restart_kthread(struct kthread *kthread)
 			proc_decref(kthread->proc);
 			kthread->proc = 0;
 		} else {
-			/* Load our page tables before potentially decreffing cur_proc */
+			/* Load our page tables before potentially decreffing cur_proc.
+			 *
+			 * We don't need to do an EPT flush here.  The EPT is flushed and
+			 * managed in sync with the VMCS.  We won't run a different VM (and
+			 * thus *need* a different EPT) without first removing the old GPC,
+			 * which ultimately will result in a flushed EPT (on x86, this
+			 * actually happens when we clear_owning_proc()). */
 			lcr3(kthread->proc->env_cr3);
 			/* Might have to clear out an existing current.  If they need to be
 			 * set later (like in restartcore), it'll be done on demand. */
@@ -587,11 +593,34 @@ static void debug_upped_sem(struct semaphore *sem)
 
 #endif /* CONFIG_SEMAPHORE_DEBUG */
 
-void print_sem_info(struct semaphore *sem)
+static bool __sem_has_pid(struct semaphore *sem, pid_t pid)
 {
 	struct kthread *kth_i;
+
+	if (pid == -1)
+		return TRUE;
+	TAILQ_FOREACH(kth_i, &sem->waiters, link) {
+		if (kth_i->proc) {
+			if (kth_i->proc->pid == pid)
+				return TRUE;
+		} else {
+			if (pid == 0)
+				return TRUE;
+		}
+	}
+	return FALSE;
+}
+
+static void print_sem_info(struct semaphore *sem, pid_t pid)
+{
+	struct kthread *kth_i;
+
 	/* Always safe to irqsave */
 	spin_lock_irqsave(&sem->lock);
+	if (!__sem_has_pid(sem, pid)) {
+		spin_unlock_irqsave(&sem->lock);
+		return;
+	}
 	printk("Semaphore %p has %d signals (neg = waiters)\n", sem,
 	       sem->nr_signals);
 	TAILQ_FOREACH(kth_i, &sem->waiters, link)
@@ -603,14 +632,14 @@ void print_sem_info(struct semaphore *sem)
 	spin_unlock_irqsave(&sem->lock);
 }
 
-void print_all_sem_info(void)
+void print_all_sem_info(pid_t pid)
 {
 #ifdef CONFIG_SEMAPHORE_DEBUG
 	struct semaphore *sem_i;
 	printk("All sems with waiters:\n");
 	spin_lock_irqsave(&sems_with_waiters_lock);
 	TAILQ_FOREACH(sem_i, &sems_with_waiters, link)
-		print_sem_info(sem_i);
+		print_sem_info(sem_i, pid);
 	spin_unlock_irqsave(&sems_with_waiters_lock);
 #else
 	printk("Failed to print all sems: build with CONFIG_SEMAPHORE_DEBUG\n");