cpuset: code-cleanup for started_after

cgroup(cgroup_scan_tasks) will initialize heap->gt for us.  This patch
removes started_after() and its helper-function.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 31 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 531b235e546f..ebbc9b082e48 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -709,36 +709,6 @@ done:
         /* Don't kfree(dattr) -- partition_sched_domains() does that. */
 }
 
-static inline int started_after_time(struct task_struct *t1,
-                                     struct timespec *time,
-                                     struct task_struct *t2)
-{
-        int start_diff = timespec_compare(&t1->start_time, time);
-        if (start_diff > 0) {
-                return 1;
-        } else if (start_diff < 0) {
-                return 0;
-        } else {
-                /*
-                 * Arbitrarily, if two processes started at the same
-                 * time, we'll say that the lower pointer value
-                 * started first. Note that t2 may have exited by now
-                 * so this may not be a valid pointer any longer, but
-                 * that's fine - it still serves to distinguish
-                 * between two tasks started (effectively)
-                 * simultaneously.
-                 */
-                return t1 > t2;
-        }
-}
-
-static inline int started_after(void *p1, void *p2)
-{
-        struct task_struct *t1 = p1;
-        struct task_struct *t2 = p2;
-        return started_after_time(t1, &t2->start_time, t2);
-}
-
 /**
  * cpuset_test_cpumask - test a task's cpus_allowed versus its cpuset's
  * @tsk: task to test
@@ -790,7 +760,12 @@ static int update_tasks_cpumask(struct cpuset *cs)
         struct ptr_heap heap;
         int retval;
 
-        retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, &started_after);
+        /*
+         * cgroup_scan_tasks() will initialize heap->gt for us.
+         * heap_init() is still needed here for we should not change
+         * cs->cpus_allowed when heap_init() fails.
+         */
+        retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
         if (retval)
                 return retval;