diff options
| author | Steve Muckle <smuckle@codeaurora.org> | 2013-05-23 15:24:57 -0700 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2016-09-28 15:15:21 +0200 |
| commit | 9648bb0846a073b25d8341a6e12b0ba9193d8973 (patch) | |
| tree | ebd6f3d6f8378e1c8ddfff86aef9512b9cc6a1ee /kernel | |
| parent | 4c47f397c0636a7bc8202ce6fa274d37e4de2eb1 (diff) | |
sched: remove migration notification from RT class
Commit 88a7e37d265 (sched: provide per cpu-cgroup option to
notify on migrations) added a notifier call when a task is moved
to a different CPU. Unfortunately the two call sites in the RT
sched class where this occurs happens with a runqueue lock held.
This can result in a deadlock if the notifier call attempts to do
something like wake up a task.
Fortunately the benefit of 88a7e37d265 comes mainly from notifying
on migration of non-RT tasks, so we can simply ignore the movements
of RT tasks.
CRs-Fixed: 491370
Change-Id: I8849d826bf1eeaf85a6f6ad872acb475247c5926
Signed-off-by: Steve Muckle <smuckle@codeaurora.org>
Signed-off-by: W4TCH0UT <ateekujjawal@gmail.com>
Conflicts:
kernel/sched/rt.c
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/rt.c | 20 |
1 files changed, 1 insertions, 19 deletions
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index c1b6096fc..692fb1e77 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -2401,7 +2401,6 @@ static int push_rt_task(struct rq *rq) struct task_struct *next_task; struct rq *lowest_rq; int ret = 0; - bool moved = false; if (!rq->rt.overloaded) return 0; @@ -2466,7 +2465,6 @@ retry: deactivate_task(rq, next_task, 0); set_task_cpu(next_task, lowest_rq->cpu); - moved = true; activate_task(lowest_rq, next_task, 0); ret = 1; @@ -2477,11 +2475,6 @@ retry: out: put_task_struct(next_task); - if (moved && task_notify_on_migrate(next_task)) - atomic_notifier_call_chain(&migration_notifier_head, - cpu_of(lowest_rq), - (void *)cpu_of(rq)); - return ret; } @@ -2621,11 +2614,9 @@ static int pull_rt_task(struct rq *this_rq) int ret = 0; #ifndef CONFIG_MT_RT_SCHED int cpu; - struct task_struct *p = NULL; + struct task_struct *p; struct rq *src_rq; #endif - bool moved = false; - int src_cpu = 0; mt_sched_printf(sched_rt_info, "0. pull_rt_task %d %d ", rt_overloaded(this_rq), this_rq->cpu); @@ -2698,10 +2689,6 @@ static int pull_rt_task(struct rq *this_rq) deactivate_task(src_rq, p, 0); set_task_cpu(p, this_cpu); activate_task(this_rq, p, 0); - - moved = true; - src_cpu = cpu_of(src_rq); - /* * We continue with the search, just in * case there's an even higher prio task @@ -2714,11 +2701,6 @@ skip: } #endif - if (moved && task_notify_on_migrate(p)) - atomic_notifier_call_chain(&migration_notifier_head, - this_cpu, - (void *)src_cpu); - return ret; } |