800d4d30c8
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>
41 lines
947 B
C
41 lines
947 B
C
#ifdef CONFIG_SCHED_AUTOGROUP
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struct autogroup {
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/*
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* reference doesn't mean how many thread attach to this
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* autogroup now. It just stands for the number of task
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* could use this autogroup.
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*/
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struct kref kref;
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struct task_group *tg;
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struct rw_semaphore lock;
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unsigned long id;
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int nice;
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};
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static inline struct task_group *
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autogroup_task_group(struct task_struct *p, struct task_group *tg);
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#else /* !CONFIG_SCHED_AUTOGROUP */
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static inline void autogroup_init(struct task_struct *init_task) { }
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static inline void autogroup_free(struct task_group *tg) { }
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static inline bool task_group_is_autogroup(struct task_group *tg)
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{
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return 0;
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}
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static inline struct task_group *
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autogroup_task_group(struct task_struct *p, struct task_group *tg)
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{
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return tg;
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}
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#ifdef CONFIG_SCHED_DEBUG
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static inline int autogroup_path(struct task_group *tg, char *buf, int buflen)
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{
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return 0;
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}
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#endif
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#endif /* CONFIG_SCHED_AUTOGROUP */
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