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author | Yong Zhang <yong.zhang0@gmail.com> | 2011-02-20 08:08:14 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2011-02-23 11:33:59 +0100 |
commit | 800d4d30c8f20bd728e5741a3b77c4859a613f7c (patch) | |
tree | 1eb329fb8a1dce1c1432c07e19494a3e1fb68499 /kernel/sched_autogroup.c | |
parent | sched, autogroup, sysctl: Use proc_dointvec_minmax() instead (diff) | |
download | linux-800d4d30c8f20bd728e5741a3b77c4859a613f7c.tar.xz linux-800d4d30c8f20bd728e5741a3b77c4859a613f7c.zip |
sched, autogroup: Stop going ahead if autogroup is disabled
when autogroup is disable from the beginning,
sched_autogroup_create_attach()
autogroup_move_group() <== 1
sched_move_task() <== 2
task_move_group_fair()
set_task_rq()
task_group()
autogroup_task_group()
We go the whole path without doing anything useful.
Then stop going further if autogroup is disabled.
But there will be a race window between 1 and 2, in which
sysctl_sched_autogroup_enabled is enabled. This issue
will be toke by following patch.
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1298185696-4403-4-git-send-email-yong.zhang0@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_autogroup.c')
-rw-r--r-- | kernel/sched_autogroup.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/sched_autogroup.c b/kernel/sched_autogroup.c index 9fb656283157..137a096ae9d8 100644 --- a/kernel/sched_autogroup.c +++ b/kernel/sched_autogroup.c @@ -161,11 +161,15 @@ autogroup_move_group(struct task_struct *p, struct autogroup *ag) p->signal->autogroup = autogroup_kref_get(ag); + if (!ACCESS_ONCE(sysctl_sched_autogroup_enabled)) + goto out; + t = p; do { sched_move_task(t); } while_each_thread(p, t); +out: unlock_task_sighand(p, &flags); autogroup_kref_put(prev); } |