[PATCH] cpuset: remove unnecessary NULL check

Remove a no longer needed test for NULL cpuset pointer, with a little
comment explaining why the test isn't needed.

Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 38f18b33de6c9a3a47d54a7980c7f5b051595fd4..bc4131141230f3f527480e39bf849a4be285a3d4 100644 (file)
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -2023,7 +2023,7 @@ void cpuset_fork(struct task_struct *child)
  * because tsk is already marked PF_EXITING, so attach_task() won't
  * mess with it, or task is a failed fork, never visible to attach_task.
  *
- * Hack:
+ * the_top_cpuset_hack:
  *
  *    Set the exiting tasks cpuset to the root cpuset (top_cpuset).
  *
@@ -2062,7 +2062,7 @@ void cpuset_exit(struct task_struct *tsk)
        struct cpuset *cs;
 
        cs = tsk->cpuset;
-       tsk->cpuset = &top_cpuset;      /* Hack - see comment above */
+       tsk->cpuset = &top_cpuset;      /* the_top_cpuset_hack - see above */
 
        if (notify_on_release(cs)) {
                char *pathbuf = NULL;
@@ -2373,12 +2373,12 @@ void __cpuset_memory_pressure_bump(void)
  *  - No need to task_lock(tsk) on this tsk->cpuset reference, as it
  *    doesn't really matter if tsk->cpuset changes after we read it,
  *    and we take manage_mutex, keeping attach_task() from changing it
- *    anyway.
+ *    anyway.  No need to check that tsk->cpuset != NULL, thanks to
+ *    the_top_cpuset_hack in cpuset_exit(), which sets an exiting tasks
+ *    cpuset to top_cpuset.
  */
-
 static int proc_cpuset_show(struct seq_file *m, void *v)
 {
-       struct cpuset *cs;
        struct task_struct *tsk;
        char *buf;
        int retval = 0;
@@ -2389,13 +2389,7 @@ static int proc_cpuset_show(struct seq_file *m, void *v)
 
        tsk = m->private;
        mutex_lock(&manage_mutex);
-       cs = tsk->cpuset;
-       if (!cs) {
-               retval = -EINVAL;
-               goto out;
-       }
-
-       retval = cpuset_path(cs, buf, PAGE_SIZE);
+       retval = cpuset_path(tsk->cpuset, buf, PAGE_SIZE);
        if (retval < 0)
                goto out;
        seq_puts(m, buf);