sched: Fix variable name misnomer, add comments

The min_vruntime variable actually stores the maximum value.
The added comment was taken from place_entity function.

Signed-off-by: Andrei Epure <epure.andrei@gmail.com>
Cc: peterz@infradead.org
Link: http://lkml.kernel.org/r/1363115544-1964-1-git-send-email-epure.andrei@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 5 insertions, 4 deletions

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 22bd9e63f61e..539760ef00c4 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -431,13 +431,13 @@ void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, unsigned long delta_exec);
  * Scheduling class tree data structure manipulation methods:
  */
 
-static inline u64 max_vruntime(u64 min_vruntime, u64 vruntime)
+static inline u64 max_vruntime(u64 max_vruntime, u64 vruntime)
 {
-        s64 delta = (s64)(vruntime - min_vruntime);
+        s64 delta = (s64)(vruntime - max_vruntime);
         if (delta > 0)
-                min_vruntime = vruntime;
+                max_vruntime = vruntime;
 
-        return min_vruntime;
+        return max_vruntime;
 }
 
 static inline u64 min_vruntime(u64 min_vruntime, u64 vruntime)
@@ -473,6 +473,7 @@ static void update_min_vruntime(struct cfs_rq *cfs_rq)
                         vruntime = min_vruntime(vruntime, se->vruntime);
         }
 
+        /* ensure we never gain time by being placed backwards. */
         cfs_rq->min_vruntime = max_vruntime(cfs_rq->min_vruntime, vruntime);
 #ifndef CONFIG_64BIT
         smp_wmb();