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-rw-r--r--kernel/exit.c9
-rw-r--r--kernel/fork.c2
-rw-r--r--kernel/sched.c10
-rw-r--r--kernel/sched_fair.c63
-rw-r--r--kernel/signal.c8
-rw-r--r--kernel/sysctl.c8
-rw-r--r--kernel/user.c45
-rw-r--r--kernel/user_namespace.c4
-rw-r--r--kernel/utsname.c2
9 files changed, 112 insertions, 39 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index 06b24b3aa37..993369ee94d 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -24,7 +24,6 @@
#include <linux/pid_namespace.h>
#include <linux/ptrace.h>
#include <linux/profile.h>
-#include <linux/signalfd.h>
#include <linux/mount.h>
#include <linux/proc_fs.h>
#include <linux/kthread.h>
@@ -86,14 +85,6 @@ static void __exit_signal(struct task_struct *tsk)
sighand = rcu_dereference(tsk->sighand);
spin_lock(&sighand->siglock);
- /*
- * Notify that this sighand has been detached. This must
- * be called with the tsk->sighand lock held. Also, this
- * access tsk->sighand internally, so it must be called
- * before tsk->sighand is reset.
- */
- signalfd_detach_locked(tsk);
-
posix_cpu_timers_exit(tsk);
if (atomic_dec_and_test(&sig->count))
posix_cpu_timers_exit_group(tsk);
diff --git a/kernel/fork.c b/kernel/fork.c
index 7332e236d36..33f12f48684 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1438,7 +1438,7 @@ static void sighand_ctor(void *data, struct kmem_cache *cachep,
struct sighand_struct *sighand = data;
spin_lock_init(&sighand->siglock);
- INIT_LIST_HEAD(&sighand->signalfd_list);
+ init_waitqueue_head(&sighand->signalfd_wqh);
}
void __init proc_caches_init(void)
diff --git a/kernel/sched.c b/kernel/sched.c
index deeb1f8e0c3..6107a0cd632 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1682,6 +1682,11 @@ void fastcall wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
p->prio = effective_prio(p);
+ if (rt_prio(p->prio))
+ p->sched_class = &rt_sched_class;
+ else
+ p->sched_class = &fair_sched_class;
+
if (!p->sched_class->task_new || !sysctl_sched_child_runs_first ||
(clone_flags & CLONE_VM) || task_cpu(p) != this_cpu ||
!current->se.on_rq) {
@@ -4550,10 +4555,7 @@ asmlinkage long sys_sched_yield(void)
struct rq *rq = this_rq_lock();
schedstat_inc(rq, yld_cnt);
- if (unlikely(rq->nr_running == 1))
- schedstat_inc(rq, yld_act_empty);
- else
- current->sched_class->yield_task(rq, current);
+ current->sched_class->yield_task(rq, current);
/*
* Since we are going to call schedule() anyway, there's
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 892616bf2c7..c9fbe8e73a4 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -43,6 +43,14 @@ unsigned int sysctl_sched_latency __read_mostly = 20000000ULL;
unsigned int sysctl_sched_min_granularity __read_mostly = 2000000ULL;
/*
+ * sys_sched_yield() compat mode
+ *
+ * This option switches the agressive yield implementation of the
+ * old scheduler back on.
+ */
+unsigned int __read_mostly sysctl_sched_compat_yield;
+
+/*
* SCHED_BATCH wake-up granularity.
* (default: 25 msec, units: nanoseconds)
*
@@ -897,19 +905,62 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int sleep)
}
/*
- * sched_yield() support is very simple - we dequeue and enqueue
+ * sched_yield() support is very simple - we dequeue and enqueue.
+ *
+ * If compat_yield is turned on then we requeue to the end of the tree.
*/
static void yield_task_fair(struct rq *rq, struct task_struct *p)
{
struct cfs_rq *cfs_rq = task_cfs_rq(p);
+ struct rb_node **link = &cfs_rq->tasks_timeline.rb_node;
+ struct sched_entity *rightmost, *se = &p->se;
+ struct rb_node *parent;
- __update_rq_clock(rq);
/*
- * Dequeue and enqueue the task to update its
- * position within the tree:
+ * Are we the only task in the tree?
+ */
+ if (unlikely(cfs_rq->nr_running == 1))
+ return;
+
+ if (likely(!sysctl_sched_compat_yield)) {
+ __update_rq_clock(rq);
+ /*
+ * Dequeue and enqueue the task to update its
+ * position within the tree:
+ */
+ dequeue_entity(cfs_rq, &p->se, 0);
+ enqueue_entity(cfs_rq, &p->se, 0);
+
+ return;
+ }
+ /*
+ * Find the rightmost entry in the rbtree:
*/
- dequeue_entity(cfs_rq, &p->se, 0);
- enqueue_entity(cfs_rq, &p->se, 0);
+ do {
+ parent = *link;
+ link = &parent->rb_right;
+ } while (*link);
+
+ rightmost = rb_entry(parent, struct sched_entity, run_node);
+ /*
+ * Already in the rightmost position?
+ */
+ if (unlikely(rightmost == se))
+ return;
+
+ /*
+ * Minimally necessary key value to be last in the tree:
+ */
+ se->fair_key = rightmost->fair_key + 1;
+
+ if (cfs_rq->rb_leftmost == &se->run_node)
+ cfs_rq->rb_leftmost = rb_next(&se->run_node);
+ /*
+ * Relink the task to the rightmost position:
+ */
+ rb_erase(&se->run_node, &cfs_rq->tasks_timeline);
+ rb_link_node(&se->run_node, parent, link);
+ rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline);
}
/*
diff --git a/kernel/signal.c b/kernel/signal.c
index 3169bed0b4d..9fb91a32edd 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -378,8 +378,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
/* We only dequeue private signals from ourselves, we don't let
* signalfd steal them
*/
- if (likely(tsk == current))
- signr = __dequeue_signal(&tsk->pending, mask, info);
+ signr = __dequeue_signal(&tsk->pending, mask, info);
if (!signr) {
signr = __dequeue_signal(&tsk->signal->shared_pending,
mask, info);
@@ -407,8 +406,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
}
}
}
- if (likely(tsk == current))
- recalc_sigpending();
+ recalc_sigpending();
if (signr && unlikely(sig_kernel_stop(signr))) {
/*
* Set a marker that we have dequeued a stop signal. Our
@@ -425,7 +423,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT))
tsk->signal->flags |= SIGNAL_STOP_DEQUEUED;
}
- if (signr && likely(tsk == current) &&
+ if (signr &&
((info->si_code & __SI_MASK) == __SI_TIMER) &&
info->si_sys_private){
/*
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 6ace893c17c..53a456ebf6d 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -303,6 +303,14 @@ static ctl_table kern_table[] = {
.proc_handler = &proc_dointvec,
},
#endif
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "sched_compat_yield",
+ .data = &sysctl_sched_compat_yield,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
#ifdef CONFIG_PROVE_LOCKING
{
.ctl_name = CTL_UNNUMBERED,
diff --git a/kernel/user.c b/kernel/user.c
index e7d11cef699..9ca2848fc35 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -55,25 +55,22 @@ struct user_struct root_user = {
/*
* These routines must be called with the uidhash spinlock held!
*/
-static inline void uid_hash_insert(struct user_struct *up, struct list_head *hashent)
+static inline void uid_hash_insert(struct user_struct *up, struct hlist_head *hashent)
{
- list_add(&up->uidhash_list, hashent);
+ hlist_add_head(&up->uidhash_node, hashent);
}
static inline void uid_hash_remove(struct user_struct *up)
{
- list_del(&up->uidhash_list);
+ hlist_del_init(&up->uidhash_node);
}
-static inline struct user_struct *uid_hash_find(uid_t uid, struct list_head *hashent)
+static inline struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
{
- struct list_head *up;
-
- list_for_each(up, hashent) {
- struct user_struct *user;
-
- user = list_entry(up, struct user_struct, uidhash_list);
+ struct user_struct *user;
+ struct hlist_node *h;
+ hlist_for_each_entry(user, h, hashent, uidhash_node) {
if(user->uid == uid) {
atomic_inc(&user->__count);
return user;
@@ -122,7 +119,7 @@ void free_uid(struct user_struct *up)
struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid)
{
- struct list_head *hashent = uidhashentry(ns, uid);
+ struct hlist_head *hashent = uidhashentry(ns, uid);
struct user_struct *up;
spin_lock_irq(&uidhash_lock);
@@ -202,6 +199,30 @@ void switch_uid(struct user_struct *new_user)
suid_keys(current);
}
+void release_uids(struct user_namespace *ns)
+{
+ int i;
+ unsigned long flags;
+ struct hlist_head *head;
+ struct hlist_node *nd;
+
+ spin_lock_irqsave(&uidhash_lock, flags);
+ /*
+ * collapse the chains so that the user_struct-s will
+ * be still alive, but not in hashes. subsequent free_uid()
+ * will free them.
+ */
+ for (i = 0; i < UIDHASH_SZ; i++) {
+ head = ns->uidhash_table + i;
+ while (!hlist_empty(head)) {
+ nd = head->first;
+ hlist_del_init(nd);
+ }
+ }
+ spin_unlock_irqrestore(&uidhash_lock, flags);
+
+ free_uid(ns->root_user);
+}
static int __init uid_cache_init(void)
{
@@ -211,7 +232,7 @@ static int __init uid_cache_init(void)
0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
for(n = 0; n < UIDHASH_SZ; ++n)
- INIT_LIST_HEAD(init_user_ns.uidhash_table + n);
+ INIT_HLIST_HEAD(init_user_ns.uidhash_table + n);
/* Insert the root user immediately (init already runs as root) */
spin_lock_irq(&uidhash_lock);
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 85af9422ea6..7af90fc4f0f 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -39,7 +39,7 @@ static struct user_namespace *clone_user_ns(struct user_namespace *old_ns)
kref_init(&ns->kref);
for (n = 0; n < UIDHASH_SZ; ++n)
- INIT_LIST_HEAD(ns->uidhash_table + n);
+ INIT_HLIST_HEAD(ns->uidhash_table + n);
/* Insert new root user. */
ns->root_user = alloc_uid(ns, 0);
@@ -81,7 +81,7 @@ void free_user_ns(struct kref *kref)
struct user_namespace *ns;
ns = container_of(kref, struct user_namespace, kref);
- free_uid(ns->root_user);
+ release_uids(ns);
kfree(ns);
}
diff --git a/kernel/utsname.c b/kernel/utsname.c
index 9d8180a0f0d..816d7b24fa0 100644
--- a/kernel/utsname.c
+++ b/kernel/utsname.c
@@ -28,7 +28,9 @@ static struct uts_namespace *clone_uts_ns(struct uts_namespace *old_ns)
if (!ns)
return ERR_PTR(-ENOMEM);
+ down_read(&uts_sem);
memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
+ up_read(&uts_sem);
kref_init(&ns->kref);
return ns;
}