diff options
| author | Joonwoo Park <joonwoop@codeaurora.org> | 2014-12-16 10:20:40 -0800 |
|---|---|---|
| committer | David Keitel <dkeitel@codeaurora.org> | 2016-03-23 20:01:22 -0700 |
| commit | 790d5d8a4ad4309dfc44ca217fe073b1e51200c1 (patch) | |
| tree | f93ae6161fa3737e9a3baa861c32cc55e1da7924 /kernel/sysctl.c | |
| parent | 90dc3fa9a78bc47e995772172cce0089b6f17ec1 (diff) | |
sched: Prevent race conditions where upmigrate_min_nice changes
When upmigrate_min_nice is changed dec_nr_big_small_task() can trigger
BUG_ON(rq->nr_big_tasks < 0). This happens when there is a task which was
considered as non-big task due to its nice > upmigrate_min_nice and later
upmigrate_min_nice is changed to higher value so the task becomes big task.
In this case runqueue still has nr_big_tasks = 0 incorrectly with current
implementation. Consequently next scheduler tick sees a big task to
schedule and try to decrease nr_big_tasks which is already 0.
Introduce sched_upmigrate_min_nice which is updated atomically and re-count
the number of big and small tasks to fix BUG_ON() triggering.
Change-Id: I6f5fc62ed22bbe5c52ec71613082a6e64f406e58
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
Diffstat (limited to 'kernel/sysctl.c')
| -rw-r--r-- | kernel/sysctl.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 5e171b035482..69a379c4573f 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -412,7 +412,7 @@ static struct ctl_table kern_table[] = { .data = &sysctl_sched_upmigrate_min_nice, .maxlen = sizeof(unsigned int), .mode = 0644, - .proc_handler = proc_dointvec, + .proc_handler = sched_hmp_proc_update_handler, }, { .procname = "sched_prefer_idle", |