xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge branch 'linus' into sched/core, to pick up fixes

Browse Source 
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar
2016-11-23 10:23:09 +01:00
parent d03266910a 23400ac997
commit ec84f00567
261 changed files with 3538 additions and 1846 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
kernel/sched/auto_group.c
View File

@@ -111,10 +111,13 @@ bool task_wants_autogroup(struct task_struct *p, struct task_group *tg)
{
if (tg != &root_task_group)
return false;
/*
* We can only assume the task group can't go away on us if
* autogroup_move_group() can see us on ->thread_group list.
* If we race with autogroup_move_group() the caller can use the old
* value of signal->autogroup but in this case sched_move_task() will
* be called again before autogroup_kref_put().
*
* However, there is no way sched_autogroup_exit_task() could tell us
* to avoid autogroup->tg, so we abuse PF_EXITING flag for this case.
*/
if (p->flags & PF_EXITING)
return false;
@@ -122,6 +125,16 @@ bool task_wants_autogroup(struct task_struct *p, struct task_group *tg)
return true;
}
void sched_autogroup_exit_task(struct task_struct *p)
{
/*
* We are going to call exit_notify() and autogroup_move_group() can't
* see this thread after that: we can no longer use signal->autogroup.
* See the PF_EXITING check in task_wants_autogroup().
*/
sched_move_task(p);
}
static void
autogroup_move_group(struct task_struct *p, struct autogroup *ag)
{
@@ -138,13 +151,20 @@ autogroup_move_group(struct task_struct *p, struct autogroup *ag)
}
p->signal->autogroup = autogroup_kref_get(ag);
if (!READ_ONCE(sysctl_sched_autogroup_enabled))
goto out;
/*
* We can't avoid sched_move_task() after we changed signal->autogroup,
* this process can already run with task_group() == prev->tg or we can
* race with cgroup code which can read autogroup = prev under rq->lock.
* In the latter case for_each_thread() can not miss a migrating thread,
* cpu_cgroup_attach() must not be possible after cgroup_exit() and it
* can't be removed from thread list, we hold ->siglock.
*
* If an exiting thread was already removed from thread list we rely on
* sched_autogroup_exit_task().
*/
for_each_thread(p, t)
sched_move_task(t);
out:
unlock_task_sighand(p, &flags);
autogroup_kref_put(prev);
}