5258f386ea
Due to these two commits:8323f26ce3sched: Fix race in task_group()800d4d30c8sched, autogroup: Stop going ahead if autogroup is disabled ... autogroup scheduling's dynamic knobs are wrecked. With both patches applied, all you have to do to crash a box is disable autogroup during boot up, then reboot.. boom, NULL pointer dereference due to800d4d30not allowing autogroup to move things, and8323f26cemaking that the only way to switch runqueues. Remove most of the (dysfunctional) knobs and turn the remaining sched_autogroup_enabled knob readonly. If the user fiddles with cgroups hereafter, once tasks are moved, autogroup won't mess with them again unless they call setsid(). No knobs, no glitz, nada, just a cute little thing folks can turn on if they don't want to muck about with cgroups and/or systemd. Signed-off-by: Mike Galbraith <efault@gmx.de> Cc: Xiaotian Feng <xtfeng@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Xiaotian Feng <dannyfeng@tencent.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: <stable@vger.kernel.org> # v3.6 Link: http://lkml.kernel.org/r/1351451963.4999.8.camel@maggy.simpson.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
58 lines
1.3 KiB
C
58 lines
1.3 KiB
C
#ifdef CONFIG_SCHED_AUTOGROUP
|
|
|
|
#include <linux/kref.h>
|
|
#include <linux/rwsem.h>
|
|
|
|
struct autogroup {
|
|
struct kref kref;
|
|
struct task_group *tg;
|
|
struct rw_semaphore lock;
|
|
unsigned long id;
|
|
int nice;
|
|
};
|
|
|
|
extern void autogroup_init(struct task_struct *init_task);
|
|
extern void autogroup_free(struct task_group *tg);
|
|
|
|
static inline bool task_group_is_autogroup(struct task_group *tg)
|
|
{
|
|
return !!tg->autogroup;
|
|
}
|
|
|
|
extern bool task_wants_autogroup(struct task_struct *p, struct task_group *tg);
|
|
|
|
static inline struct task_group *
|
|
autogroup_task_group(struct task_struct *p, struct task_group *tg)
|
|
{
|
|
if (task_wants_autogroup(p, tg))
|
|
return p->signal->autogroup->tg;
|
|
|
|
return tg;
|
|
}
|
|
|
|
extern int autogroup_path(struct task_group *tg, char *buf, int buflen);
|
|
|
|
#else /* !CONFIG_SCHED_AUTOGROUP */
|
|
|
|
static inline void autogroup_init(struct task_struct *init_task) { }
|
|
static inline void autogroup_free(struct task_group *tg) { }
|
|
static inline bool task_group_is_autogroup(struct task_group *tg)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline struct task_group *
|
|
autogroup_task_group(struct task_struct *p, struct task_group *tg)
|
|
{
|
|
return tg;
|
|
}
|
|
|
|
#ifdef CONFIG_SCHED_DEBUG
|
|
static inline int autogroup_path(struct task_group *tg, char *buf, int buflen)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#endif /* CONFIG_SCHED_AUTOGROUP */
|