From: Ben Pfaff <blp@cs.stanford.edu>
Date: Sat, 12 Feb 2011 18:04:27 +0000 (-0800)
Subject: thread: Do not disable interrupts unnecessarily while initializing stack.
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6821b6b42b3c9978d3b36728e2fd8dedaec4d20f;p=pintos-anon

thread: Do not disable interrupts unnecessarily while initializing stack.

Reported by Francis Russell <fpr02@doc.ic.ac.uk>.
---

diff --git a/solutions/p1.patch b/solutions/p1.patch
index 046989f..30c0ddd 100644
--- a/solutions/p1.patch
+++ b/solutions/p1.patch
@@ -459,7 +459,7 @@ diff -Nur ../../src/threads/thread.c src/threads/thread.c
  }
  
  /* Prints thread statistics. */
-@@ -166,12 +214,13 @@
+@@ -166,11 +214,12 @@
  thread_create (const char *name, int priority,
                 thread_func *function, void *aux) 
  {
@@ -468,9 +468,7 @@ diff -Nur ../../src/threads/thread.c src/threads/thread.c
    struct kernel_thread_frame *kf;
    struct switch_entry_frame *ef;
    struct switch_threads_frame *sf;
--  tid_t tid;
-   enum intr_level old_level;
-+  tid_t tid;
+   tid_t tid;
  
    ASSERT (function != NULL);
  
diff --git a/src/threads/thread.c b/src/threads/thread.c
index d68c123..87f22b8 100644
--- a/src/threads/thread.c
+++ b/src/threads/thread.c
@@ -171,7 +171,6 @@ thread_create (const char *name, int priority,
   struct switch_entry_frame *ef;
   struct switch_threads_frame *sf;
   tid_t tid;
-  enum intr_level old_level;
 
   ASSERT (function != NULL);
 
@@ -184,11 +183,6 @@ thread_create (const char *name, int priority,
   init_thread (t, name, priority);
   tid = t->tid = allocate_tid ();
 
-  /* Prepare thread for first run by initializing its stack.
-     Do this atomically so intermediate values for the 'stack' 
-     member cannot be observed. */
-  old_level = intr_disable ();
-
   /* Stack frame for kernel_thread(). */
   kf = alloc_frame (t, sizeof *kf);
   kf->eip = NULL;
@@ -204,8 +198,6 @@ thread_create (const char *name, int priority,
   sf->eip = switch_entry;
   sf->ebp = 0;
 
-  intr_set_level (old_level);
-
   /* Add to run queue. */
   thread_unblock (t);