1 #ifdef CONFIG_SCHED_AUTOGROUP
3 #include <linux/proc_fs.h>
4 #include <linux/seq_file.h>
5 #include <linux/kallsyms.h>
6 #include <linux/utsname.h>
8 unsigned int __read_mostly sysctl_sched_autogroup_enabled
= 1;
9 static struct autogroup autogroup_default
;
10 static atomic_t autogroup_seq_nr
;
12 static void autogroup_init(struct task_struct
*init_task
)
14 autogroup_default
.tg
= &init_task_group
;
15 init_task_group
.autogroup
= &autogroup_default
;
16 kref_init(&autogroup_default
.kref
);
17 init_rwsem(&autogroup_default
.lock
);
18 init_task
->signal
->autogroup
= &autogroup_default
;
21 static inline void autogroup_free(struct task_group
*tg
)
26 static inline void autogroup_destroy(struct kref
*kref
)
28 struct autogroup
*ag
= container_of(kref
, struct autogroup
, kref
);
30 sched_destroy_group(ag
->tg
);
33 static inline void autogroup_kref_put(struct autogroup
*ag
)
35 kref_put(&ag
->kref
, autogroup_destroy
);
38 static inline struct autogroup
*autogroup_kref_get(struct autogroup
*ag
)
44 static inline struct autogroup
*autogroup_create(void)
46 struct autogroup
*ag
= kzalloc(sizeof(*ag
), GFP_KERNEL
);
47 struct task_group
*tg
;
52 tg
= sched_create_group(&init_task_group
);
58 init_rwsem(&ag
->lock
);
59 ag
->id
= atomic_inc_return(&autogroup_seq_nr
);
68 if (printk_ratelimit()) {
69 printk(KERN_WARNING
"autogroup_create: %s failure.\n",
70 ag
? "sched_create_group()" : "kmalloc()");
73 return autogroup_kref_get(&autogroup_default
);
77 task_wants_autogroup(struct task_struct
*p
, struct task_group
*tg
)
79 if (tg
!= &root_task_group
)
82 if (p
->sched_class
!= &fair_sched_class
)
86 * We can only assume the task group can't go away on us if
87 * autogroup_move_group() can see us on ->thread_group list.
89 if (p
->flags
& PF_EXITING
)
95 static inline struct task_group
*
96 autogroup_task_group(struct task_struct
*p
, struct task_group
*tg
)
98 int enabled
= ACCESS_ONCE(sysctl_sched_autogroup_enabled
);
100 if (enabled
&& task_wants_autogroup(p
, tg
))
101 return p
->signal
->autogroup
->tg
;
107 autogroup_move_group(struct task_struct
*p
, struct autogroup
*ag
)
109 struct autogroup
*prev
;
110 struct task_struct
*t
;
113 BUG_ON(!lock_task_sighand(p
, &flags
));
115 prev
= p
->signal
->autogroup
;
117 unlock_task_sighand(p
, &flags
);
121 p
->signal
->autogroup
= autogroup_kref_get(ag
);
126 } while_each_thread(p
, t
);
128 unlock_task_sighand(p
, &flags
);
129 autogroup_kref_put(prev
);
132 /* Allocates GFP_KERNEL, cannot be called under any spinlock */
133 void sched_autogroup_create_attach(struct task_struct
*p
)
135 struct autogroup
*ag
= autogroup_create();
137 autogroup_move_group(p
, ag
);
138 /* drop extra refrence added by autogroup_create() */
139 autogroup_kref_put(ag
);
141 EXPORT_SYMBOL(sched_autogroup_create_attach
);
143 /* Cannot be called under siglock. Currently has no users */
144 void sched_autogroup_detach(struct task_struct
*p
)
146 autogroup_move_group(p
, &autogroup_default
);
148 EXPORT_SYMBOL(sched_autogroup_detach
);
150 void sched_autogroup_fork(struct signal_struct
*sig
)
152 struct task_struct
*p
= current
;
154 spin_lock_irq(&p
->sighand
->siglock
);
155 sig
->autogroup
= autogroup_kref_get(p
->signal
->autogroup
);
156 spin_unlock_irq(&p
->sighand
->siglock
);
159 void sched_autogroup_exit(struct signal_struct
*sig
)
161 autogroup_kref_put(sig
->autogroup
);
164 static int __init
setup_autogroup(char *str
)
166 sysctl_sched_autogroup_enabled
= 0;
171 __setup("noautogroup", setup_autogroup
);
173 #ifdef CONFIG_PROC_FS
175 /* Called with siglock held. */
176 int proc_sched_autogroup_set_nice(struct task_struct
*p
, int *nice
)
178 static unsigned long next
= INITIAL_JIFFIES
;
179 struct autogroup
*ag
;
182 if (*nice
< -20 || *nice
> 19)
185 err
= security_task_setnice(current
, *nice
);
189 if (*nice
< 0 && !can_nice(current
, *nice
))
192 /* this is a heavy operation taking global locks.. */
193 if (!capable(CAP_SYS_ADMIN
) && time_before(jiffies
, next
))
196 next
= HZ
/ 10 + jiffies
;
197 ag
= autogroup_kref_get(p
->signal
->autogroup
);
199 down_write(&ag
->lock
);
200 err
= sched_group_set_shares(ag
->tg
, prio_to_weight
[*nice
+ 20]);
205 autogroup_kref_put(ag
);
210 void proc_sched_autogroup_show_task(struct task_struct
*p
, struct seq_file
*m
)
212 struct autogroup
*ag
= autogroup_kref_get(p
->signal
->autogroup
);
214 down_read(&ag
->lock
);
215 seq_printf(m
, "/autogroup-%ld nice %d\n", ag
->id
, ag
->nice
);
218 autogroup_kref_put(ag
);
220 #endif /* CONFIG_PROC_FS */
222 #ifdef CONFIG_SCHED_DEBUG
223 static inline int autogroup_path(struct task_group
*tg
, char *buf
, int buflen
)
225 return snprintf(buf
, buflen
, "%s-%ld", "/autogroup", tg
->autogroup
->id
);
227 #endif /* CONFIG_SCHED_DEBUG */
229 #endif /* CONFIG_SCHED_AUTOGROUP */