Revert "ANDROID: sched/tune: Initialize raw_spin_lock in boosted_groups"

This reverts commit c5616f2f874faa20b59b116177b99bf3948586df.

If we re-init the per-cpu boostgroup spinlock every time that
we add a new boosted cgroup, we can easily wipe out (reinit)
a spinlock struct while in a critical section. We should only
be setting up the per-cpu boostgroup data, and the spin_lock
initialization need only happen once - which we're already
doing in a postcore_initcall.

For example:

     -------- CPU 0 --------   | -------- CPU1 --------
cgroupX boost group added      |
schedtune_enqueue_task         |
  acquires(bg->lock)           | cgroupY boost group added
                               |  for_each_cpu()
                               |    raw_spin_lock_init(bg->lock)
  releases(bg->lock)           |
      BUG (already unlocked)   |
                               |

This results in the following BUG from the debug spinlock code:
	BUG: spinlock already unlocked on CPU#5, rcuop/6/68

Bug: 32668852

Change-Id: I3016702780b461a0cd95e26c538cd18df27d6316
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>

diff --git a/kernel/sched/tune.c b/kernel/sched/tune.c
index 9be1bb0..d20f758 100644 (file)
--- a/kernel/sched/tune.c
+++ b/kernel/sched/tune.c
@@ -647,7 +647,6 @@ schedtune_boostgroup_init(struct schedtune *st)
                bg = &per_cpu(cpu_boost_groups, cpu);
                bg->group[st->idx].boost = 0;
                bg->group[st->idx].tasks = 0;
-               raw_spin_lock_init(&bg->lock);
        }
 
        return 0;