Parse command-line options much earlier, so that thread_mlfqs is

[pintos-anon] / src / threads / thread.c

diff --git a/src/threads/thread.c b/src/threads/thread.c
index ba1cae365f711f44474d6206bffb4e4ca25ccddc..f6768c0225432617c92c40e517a00f75f6fd72b9 100644 (file)
--- a/src/threads/thread.c
+++ b/src/threads/thread.c
@@ -52,9 +52,7 @@ static unsigned thread_ticks;   /* # of timer ticks since last yield. */
 
 /* If false (default), use round-robin scheduler.
    If true, use multi-level feedback queue scheduler.
-   Controlled by kernel command-line options "-o mlfqs".
-   Note that the command line is not parsed until well after
-   thread_init() is called. */
+   Controlled by kernel command-line option "-o mlfqs". */
 bool thread_mlfqs;
 
 static void kernel_thread (thread_func *, void *aux);
@@ -80,10 +78,6 @@ static tid_t allocate_tid (void);
    allocator before trying to create any threads with
    thread_create().
 
-   The kernel command line is not parsed until *after* this
-   function returns, so that when this function runs,
-   thread_mlfqs is always false.
-
    It is not safe to call thread_current() until this function
    finishes. */
 void
@@ -102,22 +96,14 @@ thread_init (void)
 }
 
 /* Starts preemptive thread scheduling by enabling interrupts.
-   Also creates the idle thread.
-
-   By the time this function runs, thread_mlfqs has been properly
-   initialized to its final value. */
+   Also creates the idle thread. */
 void
 thread_start (void) 
 {
-  /* Create the idle thread with maximum priority.  This ensures
-     that it will be scheduled soon after interrupts are enabled.
-     The idle thread will block almost immediately upon
-     scheduling, and subsequently it will never appear on the
-     ready list, so the priority here is otherwise
-     unimportant. */
+  /* Create the idle thread. */
   struct semaphore idle_started;
   sema_init (&idle_started, 0);
-  thread_create ("idle", PRI_MAX, idle, &idle_started);
+  thread_create ("idle", PRI_MIN, idle, &idle_started);
 
   /* Start preemptive thread scheduling. */
   intr_enable ();
@@ -394,7 +380,7 @@ idle (void *idle_started_ UNUSED)
 
          See [IA32-v2a] "HLT", [IA32-v2b] "STI", and [IA32-v3a]
          7.11.1 "HLT Instruction". */
-      asm ("sti; hlt");
+      asm volatile ("sti; hlt" : : : "memory");
     }
 }