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sched: Remove USER_SCHED

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Remove the USER_SCHED feature. It has been scheduled to be removed in
2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2

Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1263990378.24844.3.camel@localhost>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Dhaval Giani 2010-01-20 13:26:18 +01:00 committed by Ingo Molnar
parent 871e35bc97
commit 7c9414385e
7 changed files with 38 additions and 504 deletions
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15
Documentation/feature-removal-schedule.txt
View File

@ -6,21 +6,6 @@ be removed from this file.
---------------------------
What: USER_SCHED
When: 2.6.34
Why: USER_SCHED was implemented as a proof of concept for group scheduling.
The effect of USER_SCHED can already be achieved from userspace with
the help of libcgroup. The removal of USER_SCHED will also simplify
the scheduler code with the removal of one major ifdef. There are also
issues USER_SCHED has with USER_NS. A decision was taken not to fix
those and instead remove USER_SCHED. Also new group scheduling
features will not be implemented for USER_SCHED.
Who: Dhaval Giani <dhaval@linux.vnet.ibm.com>
---------------------------
What: PRISM54
When: 2.6.34

14
include/linux/sched.h
View File

@ -731,14 +731,6 @@ struct user_struct {
uid_t uid;
struct user_namespace *user_ns;
#ifdef CONFIG_USER_SCHED
struct task_group *tg;
#ifdef CONFIG_SYSFS
struct kobject kobj;
struct delayed_work work;
#endif
#endif
#ifdef CONFIG_PERF_EVENTS
atomic_long_t locked_vm;
#endif
@ -2502,13 +2494,9 @@ extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
extern void normalize_rt_tasks(void);
#ifdef CONFIG_GROUP_SCHED
#ifdef CONFIG_CGROUP_SCHED
extern struct task_group init_task_group;
#ifdef CONFIG_USER_SCHED
extern struct task_group root_task_group;
extern void set_tg_uid(struct user_struct *user);
#endif
extern struct task_group *sched_create_group(struct task_group *parent);
extern void sched_destroy_group(struct task_group *tg);

81
init/Kconfig
View File

@ -435,57 +435,6 @@ config LOG_BUF_SHIFT
config HAVE_UNSTABLE_SCHED_CLOCK
bool
config GROUP_SCHED
bool "Group CPU scheduler"
depends on EXPERIMENTAL
default n
help
This feature lets CPU scheduler recognize task groups and control CPU
bandwidth allocation to such task groups.
In order to create a group from arbitrary set of processes, use
CONFIG_CGROUPS. (See Control Group support.)
config FAIR_GROUP_SCHED
bool "Group scheduling for SCHED_OTHER"
depends on GROUP_SCHED
default GROUP_SCHED
config RT_GROUP_SCHED
bool "Group scheduling for SCHED_RR/FIFO"
depends on EXPERIMENTAL
depends on GROUP_SCHED
default n
help
This feature lets you explicitly allocate real CPU bandwidth
to users or control groups (depending on the "Basis for grouping tasks"
setting below. If enabled, it will also make it impossible to
schedule realtime tasks for non-root users until you allocate
realtime bandwidth for them.
See Documentation/scheduler/sched-rt-group.txt for more information.
choice
depends on GROUP_SCHED
prompt "Basis for grouping tasks"
default USER_SCHED
config USER_SCHED
bool "user id"
help
This option will choose userid as the basis for grouping
tasks, thus providing equal CPU bandwidth to each user.
config CGROUP_SCHED
bool "Control groups"
depends on CGROUPS
help
This option allows you to create arbitrary task groups
using the "cgroup" pseudo filesystem and control
the cpu bandwidth allocated to each such task group.
Refer to Documentation/cgroups/cgroups.txt for more
information on "cgroup" pseudo filesystem.
endchoice
menuconfig CGROUPS
boolean "Control Group support"
help
@ -606,6 +555,36 @@ config CGROUP_MEM_RES_CTLR_SWAP
Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
size is 4096bytes, 512k per 1Gbytes of swap.
menuconfig CGROUP_SCHED
bool "Group CPU scheduler"
depends on EXPERIMENTAL && CGROUPS
default n
help
This feature lets CPU scheduler recognize task groups and control CPU
bandwidth allocation to such task groups. It uses cgroups to group
tasks.
if CGROUP_SCHED
config FAIR_GROUP_SCHED
bool "Group scheduling for SCHED_OTHER"
depends on CGROUP_SCHED
default CGROUP_SCHED
config RT_GROUP_SCHED
bool "Group scheduling for SCHED_RR/FIFO"
depends on EXPERIMENTAL
depends on CGROUP_SCHED
default n
help
This feature lets you explicitly allocate real CPU bandwidth
to users or control groups (depending on the "Basis for grouping tasks"
setting below. If enabled, it will also make it impossible to
schedule realtime tasks for non-root users until you allocate
realtime bandwidth for them.
See Documentation/scheduler/sched-rt-group.txt for more information.
endif #CGROUP_SCHED
endif # CGROUPS
config MM_OWNER

8
kernel/ksysfs.c
View File

@ -197,16 +197,8 @@ static int __init ksysfs_init(void)
goto group_exit;
}
/* create the /sys/kernel/uids/ directory */
error = uids_sysfs_init();
if (error)
goto notes_exit;
return 0;
notes_exit:
if (notes_size > 0)
sysfs_remove_bin_file(kernel_kobj, &notes_attr);
group_exit:
sysfs_remove_group(kernel_kobj, &kernel_attr_group);
kset_exit:

114
kernel/sched.c
View File

@ -233,7 +233,7 @@ static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b)
*/
static DEFINE_MUTEX(sched_domains_mutex);
#ifdef CONFIG_GROUP_SCHED
#ifdef CONFIG_CGROUP_SCHED
#include <linux/cgroup.h>
@ -243,13 +243,7 @@ static LIST_HEAD(task_groups);
/* task group related information */
struct task_group {
#ifdef CONFIG_CGROUP_SCHED
struct cgroup_subsys_state css;
#endif
#ifdef CONFIG_USER_SCHED
uid_t uid;
#endif
#ifdef CONFIG_FAIR_GROUP_SCHED
/* schedulable entities of this group on each cpu */
@ -274,35 +268,7 @@ struct task_group {
struct list_head children;
};
#ifdef CONFIG_USER_SCHED
/* Helper function to pass uid information to create_sched_user() */
void set_tg_uid(struct user_struct *user)
{
user->tg->uid = user->uid;
}
/*
* Root task group.
* Every UID task group (including init_task_group aka UID-0) will
* be a child to this group.
*/
struct task_group root_task_group;
#ifdef CONFIG_FAIR_GROUP_SCHED
/* Default task group's sched entity on each cpu */
static DEFINE_PER_CPU(struct sched_entity, init_sched_entity);
/* Default task group's cfs_rq on each cpu */
static DEFINE_PER_CPU_SHARED_ALIGNED(struct cfs_rq, init_tg_cfs_rq);
#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity);
static DEFINE_PER_CPU_SHARED_ALIGNED(struct rt_rq, init_rt_rq_var);
#endif /* CONFIG_RT_GROUP_SCHED */
#else /* !CONFIG_USER_SCHED */
#define root_task_group init_task_group
#endif /* CONFIG_USER_SCHED */
/* task_group_lock serializes add/remove of task groups and also changes to
* a task group's cpu shares.
@ -318,11 +284,7 @@ static int root_task_group_empty(void)
}
#endif
#ifdef CONFIG_USER_SCHED
# define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD)
#else /* !CONFIG_USER_SCHED */
# define INIT_TASK_GROUP_LOAD NICE_0_LOAD
#endif /* CONFIG_USER_SCHED */
/*
* A weight of 0 or 1 can cause arithmetics problems.
@ -348,11 +310,7 @@ static inline struct task_group *task_group(struct task_struct *p)
{
struct task_group *tg;
#ifdef CONFIG_USER_SCHED
rcu_read_lock();
tg = __task_cred(p)->user->tg;
rcu_read_unlock();
#elif defined(CONFIG_CGROUP_SCHED)
#ifdef CONFIG_CGROUP_SCHED
tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id),
struct task_group, css);
#else
@ -383,7 +341,7 @@ static inline struct task_group *task_group(struct task_struct *p)
return NULL;
}
#endif /* CONFIG_GROUP_SCHED */
#endif /* CONFIG_CGROUP_SCHED */
/* CFS-related fields in a runqueue */
struct cfs_rq {
@ -7678,9 +7636,6 @@ void __init sched_init(void)
#ifdef CONFIG_RT_GROUP_SCHED
alloc_size += 2 * nr_cpu_ids * sizeof(void **);
#endif
#ifdef CONFIG_USER_SCHED
alloc_size *= 2;
#endif
#ifdef CONFIG_CPUMASK_OFFSTACK
alloc_size += num_possible_cpus() * cpumask_size();
#endif
@ -7694,13 +7649,6 @@ void __init sched_init(void)
init_task_group.cfs_rq = (struct cfs_rq **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
#ifdef CONFIG_USER_SCHED
root_task_group.se = (struct sched_entity **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
root_task_group.cfs_rq = (struct cfs_rq **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
#endif /* CONFIG_USER_SCHED */
#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
init_task_group.rt_se = (struct sched_rt_entity **)ptr;
@ -7709,13 +7657,6 @@ void __init sched_init(void)
init_task_group.rt_rq = (struct rt_rq **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
#ifdef CONFIG_USER_SCHED
root_task_group.rt_se = (struct sched_rt_entity **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
root_task_group.rt_rq = (struct rt_rq **)ptr;
ptr += nr_cpu_ids * sizeof(void **);
#endif /* CONFIG_USER_SCHED */
#endif /* CONFIG_RT_GROUP_SCHED */
#ifdef CONFIG_CPUMASK_OFFSTACK
for_each_possible_cpu(i) {
@ -7735,22 +7676,13 @@ void __init sched_init(void)
#ifdef CONFIG_RT_GROUP_SCHED
init_rt_bandwidth(&init_task_group.rt_bandwidth,
global_rt_period(), global_rt_runtime());
#ifdef CONFIG_USER_SCHED
init_rt_bandwidth(&root_task_group.rt_bandwidth,
global_rt_period(), RUNTIME_INF);
#endif /* CONFIG_USER_SCHED */
#endif /* CONFIG_RT_GROUP_SCHED */
#ifdef CONFIG_GROUP_SCHED
#ifdef CONFIG_CGROUP_SCHED
list_add(&init_task_group.list, &task_groups);
INIT_LIST_HEAD(&init_task_group.children);
#ifdef CONFIG_USER_SCHED
INIT_LIST_HEAD(&root_task_group.children);
init_task_group.parent = &root_task_group;
list_add(&init_task_group.siblings, &root_task_group.children);
#endif /* CONFIG_USER_SCHED */
#endif /* CONFIG_GROUP_SCHED */
#endif /* CONFIG_CGROUP_SCHED */
#if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP
update_shares_data = __alloc_percpu(nr_cpu_ids * sizeof(unsigned long),
@ -7790,25 +7722,6 @@ void __init sched_init(void)
* directly in rq->cfs (i.e init_task_group->se[] = NULL).
*/
init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL);
#elif defined CONFIG_USER_SCHED
root_task_group.shares = NICE_0_LOAD;
init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, 0, NULL);
/*
* In case of task-groups formed thr' the user id of tasks,
* init_task_group represents tasks belonging to root user.
* Hence it forms a sibling of all subsequent groups formed.
* In this case, init_task_group gets only a fraction of overall
* system cpu resource, based on the weight assigned to root
* user's cpu share (INIT_TASK_GROUP_LOAD). This is accomplished
* by letting tasks of init_task_group sit in a separate cfs_rq
* (init_tg_cfs_rq) and having one entity represent this group of
* tasks in rq->cfs (i.e init_task_group->se[] != NULL).
*/
init_tg_cfs_entry(&init_task_group,
&per_cpu(init_tg_cfs_rq, i),
&per_cpu(init_sched_entity, i), i, 1,
root_task_group.se[i]);
#endif
#endif /* CONFIG_FAIR_GROUP_SCHED */
@ -7817,12 +7730,6 @@ void __init sched_init(void)
INIT_LIST_HEAD(&rq->leaf_rt_rq_list);
#ifdef CONFIG_CGROUP_SCHED
init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL);
#elif defined CONFIG_USER_SCHED
init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, 0, NULL);
init_tg_rt_entry(&init_task_group,
&per_cpu(init_rt_rq_var, i),
&per_cpu(init_sched_rt_entity, i), i, 1,
root_task_group.rt_se[i]);
#endif
#endif
@ -8218,7 +8125,7 @@ static inline void unregister_rt_sched_group(struct task_group *tg, int cpu)
}
#endif /* CONFIG_RT_GROUP_SCHED */
#ifdef CONFIG_GROUP_SCHED
#ifdef CONFIG_CGROUP_SCHED
static void free_sched_group(struct task_group *tg)
{
free_fair_sched_group(tg);
@ -8327,7 +8234,7 @@ void sched_move_task(struct task_struct *tsk)
task_rq_unlock(rq, &flags);
}
#endif /* CONFIG_GROUP_SCHED */
#endif /* CONFIG_CGROUP_SCHED */
#ifdef CONFIG_FAIR_GROUP_SCHED
static void __set_se_shares(struct sched_entity *se, unsigned long shares)
@ -8469,13 +8376,6 @@ static int tg_schedulable(struct task_group *tg, void *data)
runtime = d->rt_runtime;
}
#ifdef CONFIG_USER_SCHED
if (tg == &root_task_group) {
period = global_rt_period();
runtime = global_rt_runtime();
}
#endif
/*
* Cannot have more runtime than the period.
*/

5
kernel/sys.c
View File

@ -569,11 +569,6 @@ static int set_user(struct cred *new)
if (!new_user)
return -EAGAIN;
if (!task_can_switch_user(new_user, current)) {
free_uid(new_user);
return -EINVAL;
}
if (atomic_read(&new_user->processes) >=
current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
new_user != INIT_USER) {

305
kernel/user.c
View File

@ -56,9 +56,6 @@ struct user_struct root_user = {
.sigpending = ATOMIC_INIT(0),
.locked_shm = 0,
.user_ns = &init_user_ns,
#ifdef CONFIG_USER_SCHED
.tg = &init_task_group,
#endif
};
/*
@ -75,268 +72,6 @@ static void uid_hash_remove(struct user_struct *up)
put_user_ns(up->user_ns);
}
#ifdef CONFIG_USER_SCHED
static void sched_destroy_user(struct user_struct *up)
{
sched_destroy_group(up->tg);
}
static int sched_create_user(struct user_struct *up)
{
int rc = 0;
up->tg = sched_create_group(&root_task_group);
if (IS_ERR(up->tg))
rc = -ENOMEM;
set_tg_uid(up);
return rc;
}
#else /* CONFIG_USER_SCHED */
static void sched_destroy_user(struct user_struct *up) { }
static int sched_create_user(struct user_struct *up) { return 0; }
#endif /* CONFIG_USER_SCHED */
#if defined(CONFIG_USER_SCHED) && defined(CONFIG_SYSFS)
static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
{
struct user_struct *user;
struct hlist_node *h;
hlist_for_each_entry(user, h, hashent, uidhash_node) {
if (user->uid == uid) {
/* possibly resurrect an "almost deleted" object */
if (atomic_inc_return(&user->__count) == 1)
cancel_delayed_work(&user->work);
return user;
}
}
return NULL;
}
static struct kset *uids_kset; /* represents the /sys/kernel/uids/ directory */
static DEFINE_MUTEX(uids_mutex);
static inline void uids_mutex_lock(void)
{
mutex_lock(&uids_mutex);
}
static inline void uids_mutex_unlock(void)
{
mutex_unlock(&uids_mutex);
}
/* uid directory attributes */
#ifdef CONFIG_FAIR_GROUP_SCHED
static ssize_t cpu_shares_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
struct user_struct *up = container_of(kobj, struct user_struct, kobj);
return sprintf(buf, "%lu\n", sched_group_shares(up->tg));
}
static ssize_t cpu_shares_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t size)
{
struct user_struct *up = container_of(kobj, struct user_struct, kobj);
unsigned long shares;
int rc;
sscanf(buf, "%lu", &shares);
rc = sched_group_set_shares(up->tg, shares);
return (rc ? rc : size);
}
static struct kobj_attribute cpu_share_attr =
__ATTR(cpu_share, 0644, cpu_shares_show, cpu_shares_store);
#endif
#ifdef CONFIG_RT_GROUP_SCHED
static ssize_t cpu_rt_runtime_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
struct user_struct *up = container_of(kobj, struct user_struct, kobj);
return sprintf(buf, "%ld\n", sched_group_rt_runtime(up->tg));
}
static ssize_t cpu_rt_runtime_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t size)
{
struct user_struct *up = container_of(kobj, struct user_struct, kobj);
unsigned long rt_runtime;
int rc;
sscanf(buf, "%ld", &rt_runtime);
rc = sched_group_set_rt_runtime(up->tg, rt_runtime);
return (rc ? rc : size);
}
static struct kobj_attribute cpu_rt_runtime_attr =
__ATTR(cpu_rt_runtime, 0644, cpu_rt_runtime_show, cpu_rt_runtime_store);
static ssize_t cpu_rt_period_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
struct user_struct *up = container_of(kobj, struct user_struct, kobj);
return sprintf(buf, "%lu\n", sched_group_rt_period(up->tg));
}
static ssize_t cpu_rt_period_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t size)
{
struct user_struct *up = container_of(kobj, struct user_struct, kobj);
unsigned long rt_period;
int rc;
sscanf(buf, "%lu", &rt_period);
rc = sched_group_set_rt_period(up->tg, rt_period);
return (rc ? rc : size);
}
static struct kobj_attribute cpu_rt_period_attr =
__ATTR(cpu_rt_period, 0644, cpu_rt_period_show, cpu_rt_period_store);
#endif
/* default attributes per uid directory */
static struct attribute *uids_attributes[] = {
#ifdef CONFIG_FAIR_GROUP_SCHED
&cpu_share_attr.attr,
#endif
#ifdef CONFIG_RT_GROUP_SCHED
&cpu_rt_runtime_attr.attr,
&cpu_rt_period_attr.attr,
#endif
NULL
};
/* the lifetime of user_struct is not managed by the core (now) */
static void uids_release(struct kobject *kobj)
{
return;
}
static struct kobj_type uids_ktype = {
.sysfs_ops = &kobj_sysfs_ops,
.default_attrs = uids_attributes,
.release = uids_release,
};
/*
* Create /sys/kernel/uids/<uid>/cpu_share file for this user
* We do not create this file for users in a user namespace (until
* sysfs tagging is implemented).
*
* See Documentation/scheduler/sched-design-CFS.txt for ramifications.
*/
static int uids_user_create(struct user_struct *up)
{
struct kobject *kobj = &up->kobj;
int error;
memset(kobj, 0, sizeof(struct kobject));
if (up->user_ns != &init_user_ns)
return 0;
kobj->kset = uids_kset;
error = kobject_init_and_add(kobj, &uids_ktype, NULL, "%d", up->uid);
if (error) {
kobject_put(kobj);
goto done;
}
kobject_uevent(kobj, KOBJ_ADD);
done:
return error;
}
/* create these entries in sysfs:
* "/sys/kernel/uids" directory
* "/sys/kernel/uids/0" directory (for root user)
* "/sys/kernel/uids/0/cpu_share" file (for root user)
*/
int __init uids_sysfs_init(void)
{
uids_kset = kset_create_and_add("uids", NULL, kernel_kobj);
if (!uids_kset)
return -ENOMEM;
return uids_user_create(&root_user);
}
/* delayed work function to remove sysfs directory for a user and free up
* corresponding structures.
*/
static void cleanup_user_struct(struct work_struct *w)
{
struct user_struct *up = container_of(w, struct user_struct, work.work);
unsigned long flags;
int remove_user = 0;
/* Make uid_hash_remove() + sysfs_remove_file() + kobject_del()
* atomic.
*/
uids_mutex_lock();
spin_lock_irqsave(&uidhash_lock, flags);
if (atomic_read(&up->__count) == 0) {
uid_hash_remove(up);
remove_user = 1;
}
spin_unlock_irqrestore(&uidhash_lock, flags);
if (!remove_user)
goto done;
if (up->user_ns == &init_user_ns) {
kobject_uevent(&up->kobj, KOBJ_REMOVE);
kobject_del(&up->kobj);
kobject_put(&up->kobj);
}
sched_destroy_user(up);
key_put(up->uid_keyring);
key_put(up->session_keyring);
kmem_cache_free(uid_cachep, up);
done:
uids_mutex_unlock();
}
/* IRQs are disabled and uidhash_lock is held upon function entry.
* IRQ state (as stored in flags) is restored and uidhash_lock released
* upon function exit.
*/
static void free_user(struct user_struct *up, unsigned long flags)
{
INIT_DELAYED_WORK(&up->work, cleanup_user_struct);
schedule_delayed_work(&up->work, msecs_to_jiffies(1000));
spin_unlock_irqrestore(&uidhash_lock, flags);
}
#else /* CONFIG_USER_SCHED && CONFIG_SYSFS */
static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
{
struct user_struct *user;
@ -352,11 +87,6 @@ static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
return NULL;
}
int uids_sysfs_init(void) { return 0; }
static inline int uids_user_create(struct user_struct *up) { return 0; }
static inline void uids_mutex_lock(void) { }
static inline void uids_mutex_unlock(void) { }
/* IRQs are disabled and uidhash_lock is held upon function entry.
* IRQ state (as stored in flags) is restored and uidhash_lock released
* upon function exit.
@ -365,32 +95,11 @@ static void free_user(struct user_struct *up, unsigned long flags)
{
uid_hash_remove(up);
spin_unlock_irqrestore(&uidhash_lock, flags);
sched_destroy_user(up);
key_put(up->uid_keyring);
key_put(up->session_keyring);
kmem_cache_free(uid_cachep, up);
}
#endif
#if defined(CONFIG_RT_GROUP_SCHED) && defined(CONFIG_USER_SCHED)
/*
* We need to check if a setuid can take place. This function should be called
* before successfully completing the setuid.
*/
int task_can_switch_user(struct user_struct *up, struct task_struct *tsk)
{
return sched_rt_can_attach(up->tg, tsk);
}
#else
int task_can_switch_user(struct user_struct *up, struct task_struct *tsk)
{
return 1;
}
#endif
/*
* Locate the user_struct for the passed UID. If found, take a ref on it. The
* caller must undo that ref with free_uid().
@ -431,8 +140,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
/* Make uid_hash_find() + uids_user_create() + uid_hash_insert()
* atomic.
*/
uids_mutex_lock();
spin_lock_irq(&uidhash_lock);
up = uid_hash_find(uid, hashent);
spin_unlock_irq(&uidhash_lock);
@ -445,14 +152,8 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
new->uid = uid;
atomic_set(&new->__count, 1);
if (sched_create_user(new) < 0)
goto out_free_user;
new->user_ns = get_user_ns(ns);
if (uids_user_create(new))
goto out_destoy_sched;
/*
* Before adding this, check whether we raced
* on adding the same user already..
@ -475,17 +176,11 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
spin_unlock_irq(&uidhash_lock);
}
uids_mutex_unlock();
return up;
out_destoy_sched:
sched_destroy_user(new);
put_user_ns(new->user_ns);
out_free_user:
kmem_cache_free(uid_cachep, new);
out_unlock:
uids_mutex_unlock();
return NULL;
}