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-rw-r--r--kernel/async.c13
-rw-r--r--kernel/auditfilter.c4
-rw-r--r--kernel/cgroup.c3
-rw-r--r--kernel/fork.c2
-rw-r--r--kernel/futex.c1208
-rw-r--r--kernel/irq/Makefile2
-rw-r--r--kernel/irq/chip.c12
-rw-r--r--kernel/irq/handle.c60
-rw-r--r--kernel/irq/internals.h5
-rw-r--r--kernel/irq/manage.c17
-rw-r--r--kernel/irq/migration.c14
-rw-r--r--kernel/irq/numa_migrate.c38
-rw-r--r--kernel/kexec.c2
-rw-r--r--kernel/kgdb.c4
-rw-r--r--kernel/kmod.c4
-rw-r--r--kernel/kprobes.c31
-rw-r--r--kernel/lockdep_internals.h4
-rw-r--r--kernel/mutex.c29
-rw-r--r--kernel/panic.c40
-rw-r--r--kernel/posix-cpu-timers.c8
-rw-r--r--kernel/power/disk.c25
-rw-r--r--kernel/power/main.c7
-rw-r--r--kernel/ptrace.c2
-rw-r--r--kernel/rcupreempt.c8
-rw-r--r--kernel/rcutree.c25
-rw-r--r--kernel/rcutree_trace.c64
-rw-r--r--kernel/rtmutex.c248
-rw-r--r--kernel/rtmutex_common.h8
-rw-r--r--kernel/sched.c306
-rw-r--r--kernel/sched_clock.c3
-rw-r--r--kernel/sched_cpupri.c2
-rw-r--r--kernel/sched_fair.c13
-rw-r--r--kernel/sched_idletask.c3
-rw-r--r--kernel/sched_rt.c2
-rw-r--r--kernel/smp.c2
-rw-r--r--kernel/softirq.c2
-rw-r--r--kernel/sysctl.c36
-rw-r--r--kernel/time/tick-common.c12
-rw-r--r--kernel/time/timekeeping.c2
-rw-r--r--kernel/timer.c86
-rw-r--r--kernel/trace/trace.c3
-rw-r--r--kernel/wait.c2
42 files changed, 1670 insertions, 691 deletions
diff --git a/kernel/async.c b/kernel/async.c
index 968ef9457d4..27235f5de19 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -92,19 +92,18 @@ extern int initcall_debug;
static async_cookie_t __lowest_in_progress(struct list_head *running)
{
struct async_entry *entry;
+
if (!list_empty(running)) {
entry = list_first_entry(running,
struct async_entry, list);
return entry->cookie;
- } else if (!list_empty(&async_pending)) {
- entry = list_first_entry(&async_pending,
- struct async_entry, list);
- return entry->cookie;
- } else {
- /* nothing in progress... next_cookie is "infinity" */
- return next_cookie;
}
+ list_for_each_entry(entry, &async_pending, list)
+ if (entry->running == running)
+ return entry->cookie;
+
+ return next_cookie; /* "infinity" value */
}
static async_cookie_t lowest_in_progress(struct list_head *running)
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index a6fe71fd5d1..713098ee5a0 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1028,7 +1028,7 @@ static void audit_update_watch(struct audit_parent *parent,
if (audit_enabled) {
struct audit_buffer *ab;
- ab = audit_log_start(NULL, GFP_KERNEL,
+ ab = audit_log_start(NULL, GFP_NOFS,
AUDIT_CONFIG_CHANGE);
audit_log_format(ab, "auid=%u ses=%u",
audit_get_loginuid(current),
@@ -1067,7 +1067,7 @@ static void audit_remove_parent_watches(struct audit_parent *parent)
e = container_of(r, struct audit_entry, rule);
if (audit_enabled) {
struct audit_buffer *ab;
- ab = audit_log_start(NULL, GFP_KERNEL,
+ ab = audit_log_start(NULL, GFP_NOFS,
AUDIT_CONFIG_CHANGE);
audit_log_format(ab, "auid=%u ses=%u",
audit_get_loginuid(current),
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 382109b5bae..a7267bfd376 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1133,8 +1133,7 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
free_cg_links:
free_cg_links(&tmp_cg_links);
drop_new_super:
- up_write(&sb->s_umount);
- deactivate_super(sb);
+ deactivate_locked_super(sb);
return ret;
}
diff --git a/kernel/fork.c b/kernel/fork.c
index b9e2edd0072..875ffbdd96d 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1409,7 +1409,7 @@ long do_fork(unsigned long clone_flags,
}
audit_finish_fork(p);
- tracehook_report_clone(trace, regs, clone_flags, nr, p);
+ tracehook_report_clone(regs, clone_flags, nr, p);
/*
* We set PF_STARTING at creation in case tracing wants to
diff --git a/kernel/futex.c b/kernel/futex.c
index eef8cd26b5e..80b5ce71659 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -19,6 +19,10 @@
* PRIVATE futexes by Eric Dumazet
* Copyright (C) 2007 Eric Dumazet <dada1@cosmosbay.com>
*
+ * Requeue-PI support by Darren Hart <dvhltc@us.ibm.com>
+ * Copyright (C) IBM Corporation, 2009
+ * Thanks to Thomas Gleixner for conceptual design and careful reviews.
+ *
* Thanks to Ben LaHaise for yelling "hashed waitqueues" loudly
* enough at me, Linus for the original (flawed) idea, Matthew
* Kirkwood for proof-of-concept implementation.
@@ -96,8 +100,8 @@ struct futex_pi_state {
*/
struct futex_q {
struct plist_node list;
- /* There can only be a single waiter */
- wait_queue_head_t waiter;
+ /* Waiter reference */
+ struct task_struct *task;
/* Which hash list lock to use: */
spinlock_t *lock_ptr;
@@ -107,7 +111,9 @@ struct futex_q {
/* Optional priority inheritance state: */
struct futex_pi_state *pi_state;
- struct task_struct *task;
+
+ /* rt_waiter storage for requeue_pi: */
+ struct rt_mutex_waiter *rt_waiter;
/* Bitset for the optional bitmasked wakeup */
u32 bitset;
@@ -193,6 +199,7 @@ static void drop_futex_key_refs(union futex_key *key)
* @uaddr: virtual address of the futex
* @fshared: 0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED
* @key: address where result is stored.
+ * @rw: mapping needs to be read/write (values: VERIFY_READ, VERIFY_WRITE)
*
* Returns a negative error code or 0
* The key words are stored in *key on success.
@@ -203,7 +210,8 @@ static void drop_futex_key_refs(union futex_key *key)
*
* lock_page() might sleep, the caller should not hold a spinlock.
*/
-static int get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key)
+static int
+get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, int rw)
{
unsigned long address = (unsigned long)uaddr;
struct mm_struct *mm = current->mm;
@@ -226,7 +234,7 @@ static int get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key)
* but access_ok() should be faster than find_vma()
*/
if (!fshared) {
- if (unlikely(!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))))
+ if (unlikely(!access_ok(rw, uaddr, sizeof(u32))))
return -EFAULT;
key->private.mm = mm;
key->private.address = address;
@@ -235,7 +243,7 @@ static int get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key)
}
again:
- err = get_user_pages_fast(address, 1, 0, &page);
+ err = get_user_pages_fast(address, 1, rw == VERIFY_WRITE, &page);
if (err < 0)
return err;
@@ -276,6 +284,25 @@ void put_futex_key(int fshared, union futex_key *key)
drop_futex_key_refs(key);
}
+/**
+ * futex_top_waiter() - Return the highest priority waiter on a futex
+ * @hb: the hash bucket the futex_q's reside in
+ * @key: the futex key (to distinguish it from other futex futex_q's)
+ *
+ * Must be called with the hb lock held.
+ */
+static struct futex_q *futex_top_waiter(struct futex_hash_bucket *hb,
+ union futex_key *key)
+{
+ struct futex_q *this;
+
+ plist_for_each_entry(this, &hb->chain, list) {
+ if (match_futex(&this->key, key))
+ return this;
+ }
+ return NULL;
+}
+
static u32 cmpxchg_futex_value_locked(u32 __user *uaddr, u32 uval, u32 newval)
{
u32 curval;
@@ -537,28 +564,160 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb,
return 0;
}
+/**
+ * futex_lock_pi_atomic() - atomic work required to acquire a pi aware futex
+ * @uaddr: the pi futex user address
+ * @hb: the pi futex hash bucket
+ * @key: the futex key associated with uaddr and hb
+ * @ps: the pi_state pointer where we store the result of the
+ * lookup
+ * @task: the task to perform the atomic lock work for. This will
+ * be "current" except in the case of requeue pi.
+ * @set_waiters: force setting the FUTEX_WAITERS bit (1) or not (0)
+ *
+ * Returns:
+ * 0 - ready to wait
+ * 1 - acquired the lock
+ * <0 - error
+ *
+ * The hb->lock and futex_key refs shall be held by the caller.
+ */
+static int futex_lock_pi_atomic(u32 __user *uaddr, struct futex_hash_bucket *hb,
+ union futex_key *key,
+ struct futex_pi_state **ps,
+ struct task_struct *task, int set_waiters)
+{
+ int lock_taken, ret, ownerdied = 0;
+ u32 uval, newval, curval;
+
+retry:
+ ret = lock_taken = 0;
+
+ /*
+ * To avoid races, we attempt to take the lock here again
+ * (by doing a 0 -> TID atomic cmpxchg), while holding all
+ * the locks. It will most likely not succeed.
+ */
+ newval = task_pid_vnr(task);
+ if (set_waiters)
+ newval |= FUTEX_WAITERS;
+
+ curval = cmpxchg_futex_value_locked(uaddr, 0, newval);
+
+ if (unlikely(curval == -EFAULT))
+ return -EFAULT;
+
+ /*
+ * Detect deadlocks.
+ */
+ if ((unlikely((curval & FUTEX_TID_MASK) == task_pid_vnr(task))))
+ return -EDEADLK;
+
+ /*
+ * Surprise - we got the lock. Just return to userspace:
+ */
+ if (unlikely(!curval))
+ return 1;
+
+ uval = curval;
+
+ /*
+ * Set the FUTEX_WAITERS flag, so the owner will know it has someone
+ * to wake at the next unlock.
+ */
+ newval = curval | FUTEX_WAITERS;
+
+ /*
+ * There are two cases, where a futex might have no owner (the
+ * owner TID is 0): OWNER_DIED. We take over the futex in this
+ * case. We also do an unconditional take over, when the owner
+ * of the futex died.
+ *
+ * This is safe as we are protected by the hash bucket lock !
+ */
+ if (unlikely(ownerdied || !(curval & FUTEX_TID_MASK))) {
+ /* Keep the OWNER_DIED bit */
+ newval = (curval & ~FUTEX_TID_MASK) | task_pid_vnr(task);
+ ownerdied = 0;
+ lock_taken = 1;
+ }
+
+ curval = cmpxchg_futex_value_locked(uaddr, uval, newval);
+
+ if (unlikely(curval == -EFAULT))
+ return -EFAULT;
+ if (unlikely(curval != uval))
+ goto retry;
+
+ /*
+ * We took the lock due to owner died take over.
+ */
+ if (unlikely(lock_taken))
+ return 1;
+
+ /*
+ * We dont have the lock. Look up the PI state (or create it if
+ * we are the first waiter):
+ */
+ ret = lookup_pi_state(uval, hb, key, ps);
+
+ if (unlikely(ret)) {
+ switch (ret) {
+ case -ESRCH:
+ /*
+ * No owner found for this futex. Check if the
+ * OWNER_DIED bit is set to figure out whether
+ * this is a robust futex or not.
+ */
+ if (get_futex_value_locked(&curval, uaddr))
+ return -EFAULT;
+
+ /*
+ * We simply start over in case of a robust
+ * futex. The code above will take the futex
+ * and return happy.
+ */
+ if (curval & FUTEX_OWNER_DIED) {
+ ownerdied = 1;
+ goto retry;
+ }
+ default:
+ break;
+ }
+ }
+
+ return ret;
+}
+
/*
* The hash bucket lock must be held when this is called.
* Afterwards, the futex_q must not be accessed.
*/
static void wake_futex(struct futex_q *q)
{
- plist_del(&q->list, &q->list.plist);
+ struct task_struct *p = q->task;
+
/*
- * The lock in wake_up_all() is a crucial memory barrier after the
- * plist_del() and also before assigning to q->lock_ptr.
+ * We set q->lock_ptr = NULL _before_ we wake up the task. If
+ * a non futex wake up happens on another CPU then the task
+ * might exit and p would dereference a non existing task
+ * struct. Prevent this by holding a reference on p across the
+ * wake up.
*/
- wake_up(&q->waiter);
+ get_task_struct(p);
+
+ plist_del(&q->list, &q->list.plist);
/*
- * The waiting task can free the futex_q as soon as this is written,
- * without taking any locks. This must come last.
- *
- * A memory barrier is required here to prevent the following store to
- * lock_ptr from getting ahead of the wakeup. Clearing the lock at the
- * end of wake_up() does not prevent this store from moving.
+ * The waiting task can free the futex_q as soon as
+ * q->lock_ptr = NULL is written, without taking any locks. A
+ * memory barrier is required here to prevent the following
+ * store to lock_ptr from getting ahead of the plist_del.
*/
smp_wmb();
q->lock_ptr = NULL;
+
+ wake_up_state(p, TASK_NORMAL);
+ put_task_struct(p);
}
static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
@@ -677,7 +836,7 @@ static int futex_wake(u32 __user *uaddr, int fshared, int nr_wake, u32 bitset)
if (!bitset)
return -EINVAL;
- ret = get_futex_key(uaddr, fshared, &key);
+ ret = get_futex_key(uaddr, fshared, &key, VERIFY_READ);
if (unlikely(ret != 0))
goto out;
@@ -687,7 +846,7 @@ static int futex_wake(u32 __user *uaddr, int fshared, int nr_wake, u32 bitset)
plist_for_each_entry_safe(this, next, head, list) {
if (match_futex (&this->key, &key)) {
- if (this->pi_state) {
+ if (this->pi_state || this->rt_waiter) {
ret = -EINVAL;
break;
}
@@ -723,10 +882,10 @@ futex_wake_op(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
int ret, op_ret;
retry:
- ret = get_futex_key(uaddr1, fshared, &key1);
+ ret = get_futex_key(uaddr1, fshared, &key1, VERIFY_READ);
if (unlikely(ret != 0))
goto out;
- ret = get_futex_key(uaddr2, fshared, &key2);
+ ret = get_futex_key(uaddr2, fshared, &key2, VERIFY_WRITE);
if (unlikely(ret != 0))
goto out_put_key1;
@@ -800,24 +959,185 @@ out:
return ret;
}
-/*
- * Requeue all waiters hashed on one physical page to another
- * physical page.
+/**
+ * requeue_futex() - Requeue a futex_q from one hb to another
+ * @q: the futex_q to requeue
+ * @hb1: the source hash_bucket
+ * @hb2: the target hash_bucket
+ * @key2: the new key for the requeued futex_q
+ */
+static inline
+void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1,
+ struct futex_hash_bucket *hb2, union futex_key *key2)
+{
+
+ /*
+ * If key1 and key2 hash to the same bucket, no need to
+ * requeue.
+ */
+ if (likely(&hb1->chain != &hb2->chain)) {
+ plist_del(&q->list, &hb1->chain);
+ plist_add(&q->list, &hb2->chain);
+ q->lock_ptr = &hb2->lock;
+#ifdef CONFIG_DEBUG_PI_LIST
+ q->list.plist.lock = &hb2->lock;
+#endif
+ }
+ get_futex_key_refs(key2);
+ q->key = *key2;
+}
+
+/**
+ * requeue_pi_wake_futex() - Wake a task that acquired the lock during requeue
+ * q: the futex_q
+ * key: the key of the requeue target futex
+ *
+ * During futex_requeue, with requeue_pi=1, it is possible to acquire the
+ * target futex if it is uncontended or via a lock steal. Set the futex_q key
+ * to the requeue target futex so the waiter can detect the wakeup on the right
+ * futex, but remove it from the hb and NULL the rt_waiter so it can detect
+ * atomic lock acquisition. Must be called with the q->lock_ptr held.
+ */
+static inline
+void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key)
+{
+ drop_futex_key_refs(&q->key);
+ get_futex_key_refs(key);
+ q->key = *key;
+
+ WARN_ON(plist_node_empty(&q->list));
+ plist_del(&q->list, &q->list.plist);
+
+ WARN_ON(!q->rt_waiter);
+ q->rt_waiter = NULL;
+
+ wake_up_state(q->task, TASK_NORMAL);
+}
+
+/**
+ * futex_proxy_trylock_atomic() - Attempt an atomic lock for the top waiter
+ * @pifutex: the user address of the to futex
+ * @hb1: the from futex hash bucket, must be locked by the caller
+ * @hb2: the to futex hash bucket, must be locked by the caller
+ * @key1: the from futex key
+ * @key2: the to futex key
+ * @ps: address to store the pi_state pointer
+ * @set_waiters: force setting the FUTEX_WAITERS bit (1) or not (0)
+ *
+ * Try and get the lock on behalf of the top waiter if we can do it atomically.
+ * Wake the top waiter if we succeed. If the caller specified set_waiters,
+ * then direct futex_lock_pi_atomic() to force setting the FUTEX_WAITERS bit.
+ * hb1 and hb2 must be held by the caller.
+ *
+ * Returns:
+ * 0 - failed to acquire the lock atomicly
+ * 1 - acquired the lock
+ * <0 - error
+ */
+static int futex_proxy_trylock_atomic(u32 __user *pifutex,
+ struct futex_hash_bucket *hb1,
+ struct futex_hash_bucket *hb2,
+ union futex_key *key1, union futex_key *key2,
+ struct futex_pi_state **ps, int set_waiters)
+{
+ struct futex_q *top_waiter = NULL;
+ u32 curval;
+ int ret;
+
+ if (get_futex_value_locked(&curval, pifutex))
+ return -EFAULT;
+
+ /*
+ * Find the top_waiter and determine if there are additional waiters.
+ * If the caller intends to requeue more than 1 waiter to pifutex,
+ * force futex_lock_pi_atomic() to set the FUTEX_WAITERS bit now,
+ * as we have means to handle the possible fault. If not, don't set
+ * the bit unecessarily as it will force the subsequent unlock to enter
+ * the kernel.
+ */
+ top_waiter = futex_top_waiter(hb1, key1);
+
+ /* There are no waiters, nothing for us to do. */
+ if (!top_waiter)
+ return 0;
+
+ /*
+ * Try to take the lock for top_waiter. Set the FUTEX_WAITERS bit in
+ * the contended case or if set_waiters is 1. The pi_state is returned
+ * in ps in contended cases.
+ */
+ ret = futex_lock_pi_atomic(pifutex, hb2, key2, ps, top_waiter->task,
+ set_waiters);
+ if (ret == 1)
+ requeue_pi_wake_futex(top_waiter, key2);
+
+ return ret;
+}
+
+/**
+ * futex_requeue() - Requeue waiters from uaddr1 to uaddr2
+ * uaddr1: source futex user address
+ * uaddr2: target futex user address
+ * nr_wake: number of waiters to wake (must be 1 for requeue_pi)
+ * nr_requeue: number of waiters to requeue (0-INT_MAX)
+ * requeue_pi: if we are attempting to requeue from a non-pi futex to a
+ * pi futex (pi to pi requeue is not supported)
+ *
+ * Requeue waiters on uaddr1 to uaddr2. In the requeue_pi case, try to acquire
+ * uaddr2 atomically on behalf of the top waiter.
+ *
+ * Returns:
+ * >=0 - on success, the number of tasks requeued or woken
+ * <0 - on error
*/
static int futex_requeue(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
- int nr_wake, int nr_requeue, u32 *cmpval)
+ int nr_wake, int nr_requeue, u32 *cmpval,
+ int requeue_pi)
{
union futex_key key1 = FUTEX_KEY_INIT, key2 = FUTEX_KEY_INIT;
+ int drop_count = 0, task_count = 0, ret;
+ struct futex_pi_state *pi_state = NULL;
struct futex_hash_bucket *hb1, *hb2;
struct plist_head *head1;
struct futex_q *this, *next;
- int ret, drop_count = 0;
+ u32 curval2;
+
+ if (requeue_pi) {
+ /*
+ * requeue_pi requires a pi_state, try to allocate it now
+ * without any locks in case it fails.
+ */
+ if (refill_pi_state_cache())
+ return -ENOMEM;
+ /*
+ * requeue_pi must wake as many tasks as it can, up to nr_wake
+ * + nr_requeue, since it acquires the rt_mutex prior to
+ * returning to userspace, so as to not leave the rt_mutex with
+ * waiters and no owner. However, second and third wake-ups
+ * cannot be predicted as they involve race conditions with the
+ * first wake and a fault while looking up the pi_state. Both
+ * pthread_cond_signal() and pthread_cond_broadcast() should
+ * use nr_wake=1.
+ */
+ if (nr_wake != 1)
+ return -EINVAL;
+ }
retry:
- ret = get_futex_key(uaddr1, fshared, &key1);
+ if (pi_state != NULL) {
+ /*
+ * We will have to lookup the pi_state again, so free this one
+ * to keep the accounting correct.
+ */
+ free_pi_state(pi_state);
+ pi_state = NULL;
+ }
+
+ ret = get_futex_key(uaddr1, fshared, &key1, VERIFY_READ);
if (unlikely(ret != 0))
goto out;
- ret = get_futex_key(uaddr2, fshared, &key2);
+ ret = get_futex_key(uaddr2, fshared, &key2,
+ requeue_pi ? VERIFY_WRITE : VERIFY_READ);
if (unlikely(ret != 0))
goto out_put_key1;
@@ -852,32 +1172,99 @@ retry_private:
}
}
+ if (requeue_pi && (task_count - nr_wake < nr_requeue)) {
+ /*
+ * Attempt to acquire uaddr2 and wake the top waiter. If we
+ * intend to requeue waiters, force setting the FUTEX_WAITERS
+ * bit. We force this here where we are able to easily handle
+ * faults rather in the requeue loop below.
+ */
+ ret = futex_proxy_trylock_atomic(uaddr2, hb1, hb2, &key1,
+ &key2, &pi_state, nr_requeue);
+
+ /*
+ * At this point the top_waiter has either taken uaddr2 or is
+ * waiting on it. If the former, then the pi_state will not
+ * exist yet, look it up one more time to ensure we have a
+ * reference to it.
+ */
+ if (ret == 1) {
+ WARN_ON(pi_state);
+ task_count++;
+ ret = get_futex_value_locked(&curval2, uaddr2);
+ if (!ret)
+ ret = lookup_pi_state(curval2, hb2, &key2,
+ &pi_state);
+ }
+
+ switch (ret) {
+ case 0:
+ break;
+ case -EFAULT:
+ double_unlock_hb(hb1, hb2);
+ put_futex_key(fshared, &key2);
+ put_futex_key(fshared, &key1);
+ ret = get_user(curval2, uaddr2);
+ if (!ret)
+ goto retry;
+ goto out;
+ case -EAGAIN:
+ /* The owner was exiting, try again. */
+ double_unlock_hb(hb1, hb2);
+ put_futex_key(fshared, &key2);
+ put_futex_key(fshared, &key1);
+ cond_resched();
+ goto retry;
+ default:
+ goto out_unlock;
+ }
+ }
+
head1 = &hb1->chain;
plist_for_each_entry_safe(this, next, head1, list) {
- if (!match_futex (&this->key, &key1))
+ if (task_count - nr_wake >= nr_requeue)
+ break;
+
+ if (!match_futex(&this->key, &key1))
continue;
- if (++ret <= nr_wake) {
+
+ WARN_ON(!requeue_pi && this->rt_waiter);
+ WARN_ON(requeue_pi && !this->rt_waiter);
+
+ /*
+ * Wake nr_wake waiters. For requeue_pi, if we acquired the
+ * lock, we already woke the top_waiter. If not, it will be
+ * woken by futex_unlock_pi().
+ */
+ if (++task_count <= nr_wake && !requeue_pi) {
wake_futex(this);
- } else {
- /*
- * If key1 and key2 hash to the same bucket, no need to
- * requeue.
- */
- if (likely(head1 != &hb2->chain)) {
- plist_del(&this->list, &hb1->chain);
- plist_add(&this->list, &hb2->chain);
- this->lock_ptr = &hb2->lock;
-#ifdef CONFIG_DEBUG_PI_LIST
- this->list.plist.lock = &hb2->lock;
-#endif
- }
- this->key = key2;
- get_futex_key_refs(&key2);
- drop_count++;
+ continue;
+ }
- if (ret - nr_wake >= nr_requeue)
- break;
+ /*
+ * Requeue nr_requeue waiters and possibly one more in the case
+ * of requeue_pi if we couldn't acquire the lock atomically.
+ */
+ if (requeue_pi) {
+ /* Prepare the waiter to take the rt_mutex. */
+ atomic_inc(&pi_state->refcount);
+ this->pi_state = pi_state;
+ ret = rt_mutex_start_proxy_lock(&pi_state->pi_mutex,
+ this->rt_waiter,
+ this->task, 1);
+ if (ret == 1) {
+ /* We got the lock. */
+ requeue_pi_wake_futex(this, &key2);
+ continue;
+ } else if (ret) {
+ /* -EDEADLK */
+ this->pi_state = NULL;
+ free_pi_state(pi_state);
+ goto out_unlock;
+ }
}
+ requeue_futex(this, hb1, hb2, &key2);
+ drop_count++;
}
out_unlock:
@@ -897,7 +1284,9 @@ out_put_keys:
out_put_key1:
put_futex_key(fshared, &key1);
out:
- return ret;
+ if (pi_state != NULL)
+ free_pi_state(pi_state);
+ return ret ? ret : task_count;
}
/* The key must be already stored in q->key. */
@@ -905,8 +1294,6 @@ static inline struct futex_hash_bucket *queue_lock(struct futex_q *q)
{
struct futex_hash_bucket *hb;
- init_waitqueue_head(&q->waiter);
-
get_futex_key_refs(&q->key);
hb = hash_futex(&q->key);
q->lock_ptr = &hb->lock;
@@ -1117,35 +1504,149 @@ handle_fault:
*/
#define FLAGS_SHARED 0x01
#define FLAGS_CLOCKRT 0x02
+#define FLAGS_HAS_TIMEOUT 0x04
static long futex_wait_restart(struct restart_block *restart);
-static int futex_wait(u32 __user *uaddr, int fshared,
- u32 val, ktime_t *abs_time, u32 bitset, int clockrt)
+/**
+ * fixup_owner() - Post lock pi_state and corner case management
+ * @uaddr: user address of the futex
+ * @fshared: whether the futex is shared (1) or not (0)
+ * @q: futex_q (contains pi_state and access to the rt_mutex)
+ * @locked: if the attempt to take the rt_mutex succeeded (1) or not (0)
+ *
+ * After attempting to lock an rt_mutex, this function is called to cleanup
+ * the pi_state owner as well as handle race conditions that may allow us to
+ * acquire the lock. Must be called with the hb lock held.
+ *
+ * Returns:
+ * 1 - success, lock taken
+ * 0 - success, lock not taken
+ * <0 - on error (-EFAULT)
+ */
+static int fixup_owner(u32 __user *uaddr, int fshared, struct futex_q *q,
+ int locked)
{
- struct task_struct *curr = current;
- struct restart_block *restart;
- DECLARE_WAITQUEUE(wait, curr);
- struct futex_hash_bucket *hb;
- struct futex_q q;
- u32 uval;
- int ret;
- struct hrtimer_sleeper t;
- int rem = 0;
+ struct task_struct *owner;
+ int ret = 0;
- if (!bitset)
- return -EINVAL;
+ if (locked) {
+ /*
+ * Got the lock. We might not be the anticipated owner if we
+ * did a lock-steal - fix up the PI-state in that case:
+ */
+ if (q->pi_state->owner != current)
+ ret = fixup_pi_state_owner(uaddr, q, current, fshared);
+ goto out;
+ }
- q.pi_state = NULL;
- q.bitset = bitset;
-retry:
- q.key = FUTEX_KEY_INIT;
- ret = get_futex_key(uaddr, fshared, &q.key);
- if (unlikely(ret != 0))
+ /*
+ * Catch the rare case, where the lock was released when we were on the
+ * way back before we locked the hash bucket.
+ */
+ if (q->pi_state->owner == current) {
+ /*
+ * Try to get the rt_mutex now. This might fail as some other
+ * task acquired the rt_mutex after we removed ourself from the
+ * rt_mutex waiters list.
+ */
+ if (rt_mutex_trylock(&q->pi_state->pi_mutex)) {
+ locked = 1;
+ goto out;
+ }
+
+ /*
+ * pi_state is incorrect, some other task did a lock steal and
+ * we returned due to timeout or signal without taking the
+ * rt_mutex. Too late. We can access the rt_mutex_owner without
+ * locking, as the other task is now blocked on the hash bucket
+ * lock. Fix the state up.
+ */
+ owner = rt_mutex_owner(&q->pi_state->pi_mutex);
+ ret = fixup_pi_state_owner(uaddr, q, owner, fshared);
goto out;
+ }
-retry_private:
- hb = queue_lock(&q);
+ /*
+ * Paranoia check. If we did not take the lock, then we should not be
+ * the owner, nor the pending owner, of the rt_mutex.
+ */
+ if (rt_mutex_owner(&q->pi_state->pi_mutex) == current)
+ printk(KERN_ERR "fixup_owner: ret = %d pi-mutex: %p "
+ "pi-state %p\n", ret,
+ q->pi_state->pi_mutex.owner,
+ q->pi_state->owner);
+
+out:
+ return ret ? ret : locked;
+}
+
+/**
+ * futex_wait_queue_me() - queue_me() and wait for wakeup, timeout, or signal
+ * @hb: the futex hash bucket, must be locked by the caller
+ * @q: the futex_q to queue up on
+ * @timeout: the prepared hrtimer_sleeper, or null for no timeout
+ */
+static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q,
+ struct hrtimer_sleeper *timeout)
+{
+ queue_me(q, hb);
+
+ /*
+ * There might have been scheduling since the queue_me(), as we
+ * cannot hold a spinlock across the get_user() in case it
+ * faults, and we cannot just set TASK_INTERRUPTIBLE state when
+ * queueing ourselves into the futex hash. This code thus has to
+ * rely on the futex_wake() code removing us from hash when it
+ * wakes us up.
+ */
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ /* Arm the timer */
+ if (timeout) {
+ hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
+ if (!hrtimer_active(&timeout->timer))
+ timeout->task = NULL;
+ }
+
+ /*
+ * !plist_node_empty() is safe here without any lock.
+ * q.lock_ptr != 0 is not safe, because of ordering against wakeup.
+ */
+ if (likely(!plist_node_empty(&q->list))) {
+ /*
+ * If the timer has already expired, current will already be
+ * flagged for rescheduling. Only call schedule if there
+ * is no timeout, or if it has yet to expire.
+ */
+ if (!timeout || timeout->task)
+ schedule();
+ }
+ __set_current_state(TASK_RUNNING);
+}
+
+/**
+ * futex_wait_setup() - Prepare to wait on a futex
+ * @uaddr: the futex userspace address
+ * @val: the expected value
+ * @fshared: whether the futex is shared (1) or not (0)
+ * @q: the associated futex_q
+ * @hb: storage for hash_bucket pointer to be returned to caller
+ *
+ * Setup the futex_q and locate the hash_bucket. Get the futex value and
+ * compare it with the expected value. Handle atomic faults internally.
+ * Return with the hb lock held and a q.key reference on success, and unlocked
+ * with no q.key reference on failure.
+ *
+ * Returns:
+ * 0 - uaddr contains val and hb has been locked
+ * <1 - -EFAULT or -EWOULDBLOCK (uaddr does not contain val) and hb is unlcoked
+ */
+static int futex_wait_setup(u32 __user *uaddr, u32 val, int fshared,
+ struct futex_q *q, struct futex_hash_bucket **hb)
+{
+ u32 uval;
+ int ret;
/*
* Access the page AFTER the hash-bucket is locked.
@@ -1163,95 +1664,83 @@ retry_private:
* A consequence is that futex_wait() can return zero and absorb
* a wakeup when *uaddr != val on entry to the syscall. This is
* rare, but normal.
- *
- * For shared futexes, we hold the mmap semaphore, so the mapping
- * cannot have changed since we looked it up in get_futex_key.
*/
+retry:
+ q->key = FUTEX_KEY_INIT;
+ ret = get_futex_key(uaddr, fshared, &q->key, VERIFY_READ);
+ if (unlikely(ret != 0))
+ return ret;
+
+retry_private:
+ *hb = queue_lock(q);
+
ret = get_futex_value_locked(&uval, uaddr);
- if (unlikely(ret)) {
- queue_unlock(&q, hb);
+ if (ret) {
+ queue_unlock(q, *hb);
ret = get_user(uval, uaddr);
if (ret)
- goto out_put_key;
+ goto out;
if (!fshared)
goto retry_private;
- put_futex_key(fshared, &q.key);
+ put_futex_key(fshared, &q->key);
goto retry;
}
- ret = -EWOULDBLOCK;
- if (unlikely(uval != val)) {
- queue_unlock(&q, hb);
- goto out_put_key;
- }
- /* Only actually queue if *uaddr contained val. */
- queue_me(&q, hb);
+ if (uval != val) {
+ queue_unlock(q, *hb);
+ ret = -EWOULDBLOCK;
+ }
- /*
- * There might have been scheduling since the queue_me(), as we
- * cannot hold a spinlock across the get_user() in case it
- * faults, and we cannot just set TASK_INTERRUPTIBLE state when
- * queueing ourselves into the futex hash. This code thus has to
- * rely on the futex_wake() code removing us from hash when it
- * wakes us up.
- */
+out:
+ if (ret)
+ put_futex_key(fshared, &q->key);
+ return ret;
+}
- /* add_wait_queue is the barrier after __set_current_state. */
- __set_current_state(TASK_INTERRUPTIBLE);
- add_wait_queue(&q.waiter, &wait);
- /*
- * !plist_node_empty() is safe here without any lock.
- * q.lock_ptr != 0 is not safe, because of ordering against wakeup.
- */
- if (likely(!plist_node_empty(&q.list))) {
- if (!abs_time)
- schedule();
- else {
- hrtimer_init_on_stack(&t.timer,
- clockrt ? CLOCK_REALTIME :
- CLOCK_MONOTONIC,
- HRTIMER_MODE_ABS);
- hrtimer_init_sleeper(&t, current);
- hrtimer_set_expires_range_ns(&t.timer, *abs_time,
- current->timer_slack_ns);
-
- hrtimer_start_expires(&t.timer, HRTIMER_MODE_ABS);
- if (!hrtimer_active(&t.timer))
- t.task = NULL;
+static int futex_wait(u32 __user *uaddr, int fshared,
+ u32 val, ktime_t *abs_time, u32 bitset, int clockrt)
+{
+ struct hrtimer_sleeper timeout, *to = NULL;
+ struct restart_block *restart;
+ struct futex_hash_bucket *hb;
+ struct futex_q q;
+ int ret;
- /*
- * the timer could have already expired, in which
- * case current would be flagged for rescheduling.
- * Don't bother calling schedule.
- */
- if (likely(t.task))
- schedule();
+ if (!bitset)
+ return -EINVAL;
- hrtimer_cancel(&t.timer);
+ q.pi_state = NULL;
+ q.bitset = bitset;
+ q.rt_waiter = NULL;
- /* Flag if a timeout occured */
- rem = (t.task == NULL);
+ if (abs_time) {
+ to = &timeout;
- destroy_hrtimer_on_stack(&t.timer);
- }
+ hrtimer_init_on_stack(&to->timer, clockrt ? CLOCK_REALTIME :
+ CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ hrtimer_init_sleeper(to, current);
+ hrtimer_set_expires_range_ns(&to->timer, *abs_time,
+ current->timer_slack_ns);
}
- __set_current_state(TASK_RUNNING);
- /*
- * NOTE: we don't remove ourselves from the waitqueue because
- * we are the only user of it.
- */
+ /* Prepare to wait on uaddr. */
+ ret = futex_wait_setup(uaddr, val, fshared, &q, &hb);
+ if (ret)
+ goto out;
+
+ /* queue_me and wait for wakeup, timeout, or a signal. */
+ futex_wait_queue_me(hb, &q, to);
/* If we were woken (and unqueued), we succeeded, whatever. */
ret = 0;
if (!unqueue_me(&q))
goto out_put_key;
ret = -ETIMEDOUT;
- if (rem)
+ if (to && !to->task)
goto out_put_key;
/*
@@ -1268,7 +1757,7 @@ retry_private:
restart->futex.val = val;
restart->futex.time = abs_time->tv64;
restart->futex.bitset = bitset;
- restart->futex.flags = 0;
+ restart->futex.flags = FLAGS_HAS_TIMEOUT;
if (fshared)
restart->futex.flags |= FLAGS_SHARED;
@@ -1280,6 +1769,10 @@ retry_private:
out_put_key:
put_futex_key(fshared, &q.key);
out:
+ if (to) {
+ hrtimer_cancel(&to->timer);
+ destroy_hrtimer_on_stack(&to->timer);
+ }
return ret;
}
@@ -1288,13 +1781,16 @@ static long futex_wait_restart(struct restart_block *restart)
{
u32 __user *uaddr = (u32 __user *)restart->futex.uaddr;
int fshared = 0;
- ktime_t t;
+ ktime_t t, *tp = NULL;
- t.tv64 = restart->futex.time;
+ if (restart->futex.flags & FLAGS_HAS_TIMEOUT) {
+ t.tv64 = restart->futex.time;
+ tp = &t;
+ }
restart->fn = do_no_restart_syscall;
if (restart->futex.flags & FLAGS_SHARED)
fshared = 1;
- return (long)futex_wait(uaddr, fshared, restart->futex.val, &t,
+ return (long)futex_wait(uaddr, fshared, restart->futex.val, tp,
restart->futex.bitset,
restart->futex.flags & FLAGS_CLOCKRT);
}
@@ -1310,11 +1806,10 @@ static int futex_lock_pi(u32 __user *uaddr, int fshared,
int detect, ktime_t *time, int trylock)
{
struct hrtimer_sleeper timeout, *to = NULL;
- struct task_struct *curr = current;
struct futex_hash_bucket *hb;
- u32 uval, newval, curval;
+ u32 uval;
struct futex_q q;
- int ret, lock_taken, ownerdied = 0;
+ int res, ret;
if (refill_pi_state_cache())
return -ENOMEM;
@@ -1328,90 +1823,25 @@ static int futex_lock_pi(u32 __user *uaddr, int fshared,
}
q.pi_state = NULL;
+ q.rt_waiter = NULL;
retry:
q.key = FUTEX_KEY_INIT;
- ret = get_futex_key(uaddr, fshared, &q.key);
+ ret = get_futex_key(uaddr, fshared, &q.key, VERIFY_WRITE);
if (unlikely(ret != 0))
goto out;
retry_private:
hb = queue_lock(&q);
-retry_locked:
- ret = lock_taken = 0;
-
- /*
- * To avoid races, we attempt to take the lock here again
- * (by doing a 0 -> TID atomic cmpxchg), while holding all
- * the locks. It will most likely not succeed.
- */
- newval = task_pid_vnr(current);
-
- curval = cmpxchg_futex_value_locked(uaddr, 0, newval);
-
- if (unlikely(curval == -EFAULT))
- goto uaddr_faulted;
-
- /*
- * Detect deadlocks. In case of REQUEUE_PI this is a valid
- * situation and we return success to user space.
- */
- if (unlikely((curval & FUTEX_TID_MASK) == task_pid_vnr(current))) {
- ret = -EDEADLK;
- goto out_unlock_put_key;
- }
-
- /*
- * Surprise - we got the lock. Just return to userspace:
- */
- if (unlikely(!curval))
- goto out_unlock_put_key;
-
- uval = curval;
-
- /*
- * Set the WAITERS flag, so the owner will know it has someone
- * to wake at next unlock
- */
- newval = curval | FUTEX_WAITERS;
-
- /*
- * There are two cases, where a futex might have no owner (the
- * owner TID is 0): OWNER_DIED. We take over the futex in this
- * case. We also do an unconditional take over, when the owner
- * of the futex died.
- *
- * This is safe as we are protected by the hash bucket lock !
- */
- if (unlikely(ownerdied || !(curval & FUTEX_TID_MASK))) {
- /* Keep the OWNER_DIED bit */
- newval = (curval & ~FUTEX_TID_MASK) | task_pid_vnr(current);
- ownerdied = 0;
- lock_taken = 1;
- }
-
- curval = cmpxchg_futex_value_locked(uaddr, uval, newval);
-
- if (unlikely(curval == -EFAULT))
- goto uaddr_faulted;
- if (unlikely(curval != uval))
- goto retry_locked;
-
- /*
- * We took the lock due to owner died take over.
- */
- if (unlikely(lock_taken))
- goto out_unlock_put_key;
-
- /*
- * We dont have the lock. Look up the PI state (or create it if
- * we are the first waiter):
- */
- ret = lookup_pi_state(uval, hb, &q.key, &q.pi_state);
-
+ ret = futex_lock_pi_atomic(uaddr, hb, &q.key, &q.pi_state, current, 0);
if (unlikely(ret)) {
switch (ret) {
-
+ case 1:
+ /* We got the lock. */
+ ret = 0;
+ goto out_unlock_put_key;
+ case -EFAULT:
+ goto uaddr_faulted;
case -EAGAIN:
/*
* Task is exiting and we just wait for the
@@ -1421,25 +1851,6 @@ retry_locked:
put_futex_key(fshared, &q.key);
cond_resched();
goto retry;
-
- case -ESRCH:
- /*
- * No owner found for this futex. Check if the
- * OWNER_DIED bit is set to figure out whether
- * this is a robust futex or not.
- */
- if (get_futex_value_locked(&curval, uaddr))
- goto uaddr_faulted;
-
- /*
- * We simply start over in case of a robust
- * futex. The code above will take the futex
- * and return happy.
- */
- if (curval & FUTEX_OWNER_DIED) {
- ownerdied = 1;
- goto retry_locked;
- }
default:
goto out_unlock_put_key;
}
@@ -1463,71 +1874,21 @@ retry_locked:
}
spin_lock(q.lock_ptr);
-
- if (!ret) {
- /*
- * Got the lock. We might not be the anticipated owner
- * if we did a lock-steal - fix up the PI-state in
- * that case:
- */
- if (q.pi_state->owner != curr)
- ret = fixup_pi_state_owner(uaddr, &q, curr, fshared);
- } else {
- /*
- * Catch the rare case, where the lock was released
- * when we were on the way back before we locked the
- * hash bucket.
- */
- if (q.pi_state->owner == curr) {
- /*
- * Try to get the rt_mutex now. This might
- * fail as some other task acquired the
- * rt_mutex after we removed ourself from the
- * rt_mutex waiters list.
- */
- if (rt_mutex_trylock(&q.pi_state->pi_mutex))
- ret = 0;
- else {
- /*
- * pi_state is incorrect, some other
- * task did a lock steal and we
- * returned due to timeout or signal
- * without taking the rt_mutex. Too
- * late. We can access the
- * rt_mutex_owner without locking, as
- * the other task is now blocked on
- * the hash bucket lock. Fix the state
- * up.
- */
- struct task_struct *owner;
- int res;
-
- owner = rt_mutex_owner(&q.pi_state->pi_mutex);
- res = fixup_pi_state_owner(uaddr, &q, owner,
- fshared);
-
- /* propagate -EFAULT, if the fixup failed */
- if (res)
- ret = res;
- }
- } else {
- /*
- * Paranoia check. If we did not take the lock
- * in the trylock above, then we should not be
- * the owner of the rtmutex, neither the real
- * nor the pending one:
- */
- if (rt_mutex_owner(&q.pi_state->pi_mutex) == curr)
- printk(KERN_ERR "futex_lock_pi: ret = %d "
- "pi-mutex: %p pi-state %p\n", ret,
- q.pi_state->pi_mutex.owner,
- q.pi_state->owner);
- }
- }
+ /*
+ * Fixup the pi_state owner and possibly acquire the lock if we
+ * haven't already.
+ */
+ res = fixup_owner(uaddr, fshared, &q, !ret);
+ /*
+ * If fixup_owner() returned an error, proprogate that. If it acquired
+ * the lock, clear our -ETIMEDOUT or -EINTR.
+ */
+ if (res)
+ ret = (res < 0) ? res : 0;
/*
- * If fixup_pi_state_owner() faulted and was unable to handle the
- * fault, unlock it and return the fault to userspace.
+ * If fixup_owner() faulted and was unable to handle the fault, unlock
+ * it and return the fault to userspace.
*/
if (ret && (rt_mutex_owner(&q.pi_state->pi_mutex) == current))
rt_mutex_unlock(&q.pi_state->pi_mutex);
@@ -1535,9 +1896,7 @@ retry_locked:
/* Unqueue and drop the lock */
unqueue_me_pi(&q);
- if (to)
- destroy_hrtimer_on_stack(&to->timer);
- return ret != -EINTR ? ret : -ERESTARTNOINTR;
+ goto out;
out_unlock_put_key:
queue_unlock(&q, hb);
@@ -1547,7 +1906,7 @@ out_put_key:
out:
if (to)
destroy_hrtimer_on_stack(&to->timer);
- return ret;
+ return ret != -EINTR ? ret : -ERESTARTNOINTR;
uaddr_faulted:
/*
@@ -1570,7 +1929,6 @@ uaddr_faulted:
goto retry;
}
-
/*
* Userspace attempted a TID -> 0 atomic transition, and failed.
* This is the in-kernel slowpath: we look up the PI state (if any),
@@ -1594,7 +1952,7 @@ retry:
if ((uval & FUTEX_TID_MASK) != task_pid_vnr(current))
return -EPERM;
- ret = get_futex_key(uaddr, fshared, &key);
+ ret = get_futex_key(uaddr, fshared, &key, VERIFY_WRITE);
if (unlikely(ret != 0))
goto out;
@@ -1672,6 +2030,229 @@ pi_faulted:
return ret;
}
+/**
+ * handle_early_requeue_pi_wakeup() - Detect early wakeup on the initial futex
+ * @hb: the hash_bucket futex_q was original enqueued on
+ * @q: the futex_q woken while waiting to be requeued
+ * @key2: the futex_key of the requeue target futex
+ * @timeout: the timeout associated with the wait (NULL if none)
+ *
+ * Detect if the task was woken on the initial futex as opposed to the requeue
+ * target futex. If so, determine if it was a timeout or a signal that caused
+ * the wakeup and return the appropriate error code to the caller. Must be
+ * called with the hb lock held.
+ *
+ * Returns
+ * 0 - no early wakeup detected
+ * <0 - -ETIMEDOUT or -ERESTARTNOINTR
+ */
+static inline
+int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
+ struct futex_q *q, union futex_key *key2,
+ struct hrtimer_sleeper *timeout)
+{
+ int ret = 0;
+
+ /*
+ * With the hb lock held, we avoid races while we process the wakeup.
+ * We only need to hold hb (and not hb2) to ensure atomicity as the
+ * wakeup code can't change q.key from uaddr to uaddr2 if we hold hb.
+ * It can't be requeued from uaddr2 to something else since we don't
+ * support a PI aware source futex for requeue.
+ */
+ if (!match_futex(&q->key, key2)) {
+ WARN_ON(q->lock_ptr && (&hb->lock != q->lock_ptr));
+ /*
+ * We were woken prior to requeue by a timeout or a signal.
+ * Unqueue the futex_q and determine which it was.
+ */
+ plist_del(&q->list, &q->list.plist);
+ drop_futex_key_refs(&q->key);
+
+ if (timeout && !timeout->task)
+ ret = -ETIMEDOUT;
+ else
+ ret = -ERESTARTNOINTR;
+ }
+ return ret;
+}
+
+/**
+ * futex_wait_requeue_pi() - Wait on uaddr and take uaddr2
+ * @uaddr: the futex we initialyl wait on (non-pi)
+ * @fshared: whether the futexes are shared (1) or not (0). They must be
+ * the same type, no requeueing from private to shared, etc.
+ * @val: the expected value of uaddr
+ * @abs_time: absolute timeout
+ * @bitset: 32 bit wakeup bitset set by userspace, defaults to all.
+ * @clockrt: whether to use CLOCK_REALTIME (1) or CLOCK_MONOTONIC (0)
+ * @uaddr2: the pi futex we will take prior to returning to user-space
+ *
+ * The caller will wait on uaddr and will be requeued by futex_requeue() to
+ * uaddr2 which must be PI aware. Normal wakeup will wake on uaddr2 and
+ * complete the acquisition of the rt_mutex prior to returning to userspace.
+ * This ensures the rt_mutex maintains an owner when it has waiters; without
+ * one, the pi logic wouldn't know which task to boost/deboost, if there was a
+ * need to.
+ *
+ * We call schedule in futex_wait_queue_me() when we enqueue and return there
+ * via the following:
+ * 1) wakeup on uaddr2 after an atomic lock acquisition by futex_requeue()
+ * 2) wakeup on uaddr2 after a requeue and subsequent unlock
+ * 3) signal (before or after requeue)
+ * 4) timeout (before or after requeue)
+ *
+ * If 3, we setup a restart_block with futex_wait_requeue_pi() as the function.
+ *
+ * If 2, we may then block on trying to take the rt_mutex and return via:
+ * 5) successful lock
+ * 6) signal
+ * 7) timeout
+ * 8) other lock acquisition failure
+ *
+ * If 6, we setup a restart_block with futex_lock_pi() as the function.
+ *
+ * If 4 or 7, we cleanup and return with -ETIMEDOUT.
+ *
+ * Returns:
+ * 0 - On success
+ * <0 - On error
+ */
+static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared,
+ u32 val, ktime_t *abs_time, u32 bitset,
+ int clockrt, u32 __user *uaddr2)
+{
+ struct hrtimer_sleeper timeout, *to = NULL;
+ struct rt_mutex_waiter rt_waiter;
+ struct rt_mutex *pi_mutex = NULL;
+ struct futex_hash_bucket *hb;
+ union futex_key key2;
+ struct futex_q q;
+ int res, ret;
+
+ if (!bitset)
+ return -EINVAL;
+
+ if (abs_time) {
+ to = &timeout;
+ hrtimer_init_on_stack(&to->timer, clockrt ? CLOCK_REALTIME :
+ CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ hrtimer_init_sleeper(to, current);
+ hrtimer_set_expires_range_ns(&to->timer, *abs_time,
+ current->timer_slack_ns);
+ }
+
+ /*
+ * The waiter is allocated on our stack, manipulated by the requeue
+ * code while we sleep on uaddr.
+ */
+ debug_rt_mutex_init_waiter(&rt_waiter);
+ rt_waiter.task = NULL;
+
+ q.pi_state = NULL;
+ q.bitset = bitset;
+ q.rt_waiter = &rt_waiter;
+
+ key2 = FUTEX_KEY_INIT;
+ ret = get_futex_key(uaddr2, fshared, &key2, VERIFY_WRITE);
+ if (unlikely(ret != 0))
+ goto out;
+
+ /* Prepare to wait on uaddr. */
+ ret = futex_wait_setup(uaddr, val, fshared, &q, &hb);
+ if (ret)
+ goto out_key2;
+
+ /* Queue the futex_q, drop the hb lock, wait for wakeup. */
+ futex_wait_queue_me(hb, &q, to);
+
+ spin_lock(&hb->lock);
+ ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to);
+ spin_unlock(&hb->lock);
+ if (ret)
+ goto out_put_keys;
+
+ /*
+ * In order for us to be here, we know our q.key == key2, and since
+ * we took the hb->lock above, we also know that futex_requeue() has
+ * completed and we no longer have to concern ourselves with a wakeup
+ * race with the atomic proxy lock acquition by the requeue code.
+ */
+
+ /* Check if the requeue code acquired the second futex for us. */
+ if (!q.rt_waiter) {
+ /*
+ * Got the lock. We might not be the anticipated owner if we
+ * did a lock-steal - fix up the PI-state in that case.
+ */
+ if (q.pi_state && (q.pi_state->owner != current)) {
+ spin_lock(q.lock_ptr);
+ ret = fixup_pi_state_owner(uaddr2, &q, current,
+ fshared);
+ spin_unlock(q.lock_ptr);
+ }
+ } else {
+ /*
+ * We have been woken up by futex_unlock_pi(), a timeout, or a
+ * signal. futex_unlock_pi() will not destroy the lock_ptr nor
+ * the pi_state.
+ */
+ WARN_ON(!&q.pi_state);
+ pi_mutex = &q.pi_state->pi_mutex;
+ ret = rt_mutex_finish_proxy_lock(pi_mutex, to, &rt_waiter, 1);
+ debug_rt_mutex_free_waiter(&rt_waiter);
+
+ spin_lock(q.lock_ptr);
+ /*
+ * Fixup the pi_state owner and possibly acquire the lock if we
+ * haven't already.
+ */
+ res = fixup_owner(uaddr2, fshared, &q, !ret);
+ /*
+ * If fixup_owner() returned an error, proprogate that. If it
+ * acquired the lock, clear our -ETIMEDOUT or -EINTR.
+ */
+ if (res)
+ ret = (res < 0) ? res : 0;
+
+ /* Unqueue and drop the lock. */
+ unqueue_me_pi(&q);
+ }
+
+ /*
+ * If fixup_pi_state_owner() faulted and was unable to handle the
+ * fault, unlock the rt_mutex and return the fault to userspace.
+ */
+ if (ret == -EFAULT) {
+ if (rt_mutex_owner(pi_mutex) == current)
+ rt_mutex_unlock(pi_mutex);
+ } else if (ret == -EINTR) {
+ /*
+ * We've already been requeued, but we have no way to
+ * restart by calling futex_lock_pi() directly. We
+ * could restart the syscall, but that will look at
+ * the user space value and return right away. So we
+ * drop back with EWOULDBLOCK to tell user space that
+ * "val" has been changed. That's the same what the
+ * restart of the syscall would do in
+ * futex_wait_setup().
+ */
+ ret = -EWOULDBLOCK;
+ }
+
+out_put_keys:
+ put_futex_key(fshared, &q.key);
+out_key2:
+ put_futex_key(fshared, &key2);
+
+out:
+ if (to) {
+ hrtimer_cancel(&to->timer);
+ destroy_hrtimer_on_stack(&to->timer);
+ }
+ return ret;
+}
+
/*
* Support for robust futexes: the kernel cleans up held futexes at
* thread exit time.
@@ -1894,7 +2475,7 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
fshared = 1;
clockrt = op & FUTEX_CLOCK_REALTIME;
- if (clockrt && cmd != FUTEX_WAIT_BITSET)
+ if (clockrt && cmd != FUTEX_WAIT_BITSET && cmd != FUTEX_WAIT_REQUEUE_PI)
return -ENOSYS;
switch (cmd) {
@@ -1909,10 +2490,11 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
ret = futex_wake(uaddr, fshared, val, val3);
break;
case FUTEX_REQUEUE:
- ret = futex_requeue(uaddr, fshared, uaddr2, val, val2, NULL);
+ ret = futex_requeue(uaddr, fshared, uaddr2, val, val2, NULL, 0);
break;
case FUTEX_CMP_REQUEUE:
- ret = futex_requeue(uaddr, fshared, uaddr2, val, val2, &val3);
+ ret = futex_requeue(uaddr, fshared, uaddr2, val, val2, &val3,
+ 0);
break;
case FUTEX_WAKE_OP:
ret = futex_wake_op(uaddr, fshared, uaddr2, val, val2, val3);
@@ -1929,6 +2511,15 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
if (futex_cmpxchg_enabled)
ret = futex_lock_pi(uaddr, fshared, 0, timeout, 1);
break;
+ case FUTEX_WAIT_REQUEUE_PI:
+ val3 = FUTEX_BITSET_MATCH_ANY;
+ ret = futex_wait_requeue_pi(uaddr, fshared, val, timeout, val3,
+ clockrt, uaddr2);
+ break;
+ case FUTEX_CMP_REQUEUE_PI:
+ ret = futex_requeue(uaddr, fshared, uaddr2, val, val2, &val3,
+ 1);
+ break;
default:
ret = -ENOSYS;
}
@@ -1946,7 +2537,8 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
int cmd = op & FUTEX_CMD_MASK;
if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI ||
- cmd == FUTEX_WAIT_BITSET)) {
+ cmd == FUTEX_WAIT_BITSET ||
+ cmd == FUTEX_WAIT_REQUEUE_PI)) {
if (copy_from_user(&ts, utime, sizeof(ts)) != 0)
return -EFAULT;
if (!timespec_valid(&ts))
@@ -1958,11 +2550,11 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
tp = &t;
}
/*
- * requeue parameter in 'utime' if cmd == FUTEX_REQUEUE.
+ * requeue parameter in 'utime' if cmd == FUTEX_*_REQUEUE_*.
* number of waiters to wake in 'utime' if cmd == FUTEX_WAKE_OP.
*/
if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE ||
- cmd == FUTEX_WAKE_OP)
+ cmd == FUTEX_CMP_REQUEUE_PI || cmd == FUTEX_WAKE_OP)
val2 = (u32) (unsigned long) utime;
return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);
diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile
index 3394f8f5296..7d047808419 100644
--- a/kernel/irq/Makefile
+++ b/kernel/irq/Makefile
@@ -3,5 +3,5 @@ obj-y := handle.o manage.o spurious.o resend.o chip.o devres.o
obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o
obj-$(CONFIG_PROC_FS) += proc.o
obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o
-obj-$(CONFIG_NUMA_MIGRATE_IRQ_DESC) += numa_migrate.o
+obj-$(CONFIG_NUMA_IRQ_DESC) += numa_migrate.o
obj-$(CONFIG_PM_SLEEP) += pm.o
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index c687ba4363f..13c68e71b72 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -359,7 +359,6 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc)
spin_lock(&desc->lock);
mask_ack_irq(desc, irq);
- desc = irq_remap_to_desc(irq, desc);
if (unlikely(desc->status & IRQ_INPROGRESS))
goto out_unlock;
@@ -438,7 +437,6 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
desc->status &= ~IRQ_INPROGRESS;
out:
desc->chip->eoi(irq);
- desc = irq_remap_to_desc(irq, desc);
spin_unlock(&desc->lock);
}
@@ -475,7 +473,6 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
!desc->action)) {
desc->status |= (IRQ_PENDING | IRQ_MASKED);
mask_ack_irq(desc, irq);
- desc = irq_remap_to_desc(irq, desc);
goto out_unlock;
}
kstat_incr_irqs_this_cpu(irq, desc);
@@ -483,7 +480,6 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
/* Start handling the irq */
if (desc->chip->ack)
desc->chip->ack(irq);
- desc = irq_remap_to_desc(irq, desc);
/* Mark the IRQ currently in progress.*/
desc->status |= IRQ_INPROGRESS;
@@ -544,10 +540,8 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);
- if (desc->chip->eoi) {
+ if (desc->chip->eoi)
desc->chip->eoi(irq);
- desc = irq_remap_to_desc(irq, desc);
- }
}
void
@@ -582,10 +576,8 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
/* Uninstall? */
if (handle == handle_bad_irq) {
- if (desc->chip != &no_irq_chip) {
+ if (desc->chip != &no_irq_chip)
mask_ack_irq(desc, irq);
- desc = irq_remap_to_desc(irq, desc);
- }
desc->status |= IRQ_DISABLED;
desc->depth = 1;
}
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index d82142be8dd..18041a254d3 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -11,6 +11,7 @@
*/
#include <linux/irq.h>
+#include <linux/slab.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/interrupt.h>
@@ -81,45 +82,48 @@ static struct irq_desc irq_desc_init = {
.lock = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
};
-void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr)
+void __ref init_kstat_irqs(struct irq_desc *desc, int node, int nr)
{
- int node;
void *ptr;
- node = cpu_to_node(cpu);
- ptr = kzalloc_node(nr * sizeof(*desc->kstat_irqs), GFP_ATOMIC, node);
+ if (slab_is_available())
+ ptr = kzalloc_node(nr * sizeof(*desc->kstat_irqs),
+ GFP_ATOMIC, node);
+ else
+ ptr = alloc_bootmem_node(NODE_DATA(node),
+ nr * sizeof(*desc->kstat_irqs));
/*
* don't overwite if can not get new one
* init_copy_kstat_irqs() could still use old one
*/
if (ptr) {
- printk(KERN_DEBUG " alloc kstat_irqs on cpu %d node %d\n",
- cpu, node);
+ printk(KERN_DEBUG " alloc kstat_irqs on node %d\n", node);
desc->kstat_irqs = ptr;
}
}
-static void init_one_irq_desc(int irq, struct irq_desc *desc, int cpu)
+static void init_one_irq_desc(int irq, struct irq_desc *desc, int node)
{
memcpy(desc, &irq_desc_init, sizeof(struct irq_desc));
spin_lock_init(&desc->lock);
desc->irq = irq;
#ifdef CONFIG_SMP
- desc->cpu = cpu;
+ desc->node = node;
#endif
lockdep_set_class(&desc->lock, &irq_desc_lock_class);
- init_kstat_irqs(desc, cpu, nr_cpu_ids);
+ init_kstat_irqs(desc, node, nr_cpu_ids);
if (!desc->kstat_irqs) {
printk(KERN_ERR "can not alloc kstat_irqs\n");
BUG_ON(1);
}
- if (!init_alloc_desc_masks(desc, cpu, false)) {
+ if (!alloc_desc_masks(desc, node, false)) {
printk(KERN_ERR "can not alloc irq_desc cpumasks\n");
BUG_ON(1);
}
- arch_init_chip_data(desc, cpu);
+ init_desc_masks(desc);
+ arch_init_chip_data(desc, node);
}
/*
@@ -169,7 +173,8 @@ int __init early_irq_init(void)
desc[i].irq = i;
desc[i].kstat_irqs = kstat_irqs_legacy + i * nr_cpu_ids;
lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
- init_alloc_desc_masks(&desc[i], 0, true);
+ alloc_desc_masks(&desc[i], 0, true);
+ init_desc_masks(&desc[i]);
irq_desc_ptrs[i] = desc + i;
}
@@ -187,11 +192,10 @@ struct irq_desc *irq_to_desc(unsigned int irq)
return NULL;
}
-struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu)
+struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
{
struct irq_desc *desc;
unsigned long flags;
- int node;
if (irq >= nr_irqs) {
WARN(1, "irq (%d) >= nr_irqs (%d) in irq_to_desc_alloc\n",
@@ -210,15 +214,17 @@ struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu)
if (desc)
goto out_unlock;
- node = cpu_to_node(cpu);
- desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
- printk(KERN_DEBUG " alloc irq_desc for %d on cpu %d node %d\n",
- irq, cpu, node);
+ if (slab_is_available())
+ desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
+ else
+ desc = alloc_bootmem_node(NODE_DATA(node), sizeof(*desc));
+
+ printk(KERN_DEBUG " alloc irq_desc for %d on node %d\n", irq, node);
if (!desc) {
printk(KERN_ERR "can not alloc irq_desc\n");
BUG_ON(1);
}
- init_one_irq_desc(irq, desc, cpu);
+ init_one_irq_desc(irq, desc, node);
irq_desc_ptrs[irq] = desc;
@@ -256,7 +262,8 @@ int __init early_irq_init(void)
for (i = 0; i < count; i++) {
desc[i].irq = i;
- init_alloc_desc_masks(&desc[i], 0, true);
+ alloc_desc_masks(&desc[i], 0, true);
+ init_desc_masks(&desc[i]);
desc[i].kstat_irqs = kstat_irqs_all[i];
}
return arch_early_irq_init();
@@ -267,7 +274,7 @@ struct irq_desc *irq_to_desc(unsigned int irq)
return (irq < NR_IRQS) ? irq_desc + irq : NULL;
}
-struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu)
+struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node)
{
return irq_to_desc(irq);
}
@@ -363,8 +370,6 @@ irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
irqreturn_t ret, retval = IRQ_NONE;
unsigned int status = 0;
- WARN_ONCE(!in_irq(), "BUG: IRQ handler called from non-hardirq context!");
-
if (!(action->flags & IRQF_DISABLED))
local_irq_enable_in_hardirq();
@@ -455,11 +460,8 @@ unsigned int __do_IRQ(unsigned int irq)
/*
* No locking required for CPU-local interrupts:
*/
- if (desc->chip->ack) {
+ if (desc->chip->ack)
desc->chip->ack(irq);
- /* get new one */
- desc = irq_remap_to_desc(irq, desc);
- }
if (likely(!(desc->status & IRQ_DISABLED))) {
action_ret = handle_IRQ_event(irq, desc->action);
if (!noirqdebug)
@@ -470,10 +472,8 @@ unsigned int __do_IRQ(unsigned int irq)
}
spin_lock(&desc->lock);
- if (desc->chip->ack) {
+ if (desc->chip->ack)
desc->chip->ack(irq);
- desc = irq_remap_to_desc(irq, desc);
- }
/*
* REPLAY is when Linux resends an IRQ that was dropped earlier
* WAITING is used by probe to mark irqs that are being tested
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 01ce20eab38..73468253143 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -16,7 +16,7 @@ extern void __disable_irq(struct irq_desc *desc, unsigned int irq, bool susp);
extern void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume);
extern struct lock_class_key irq_desc_lock_class;
-extern void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr);
+extern void init_kstat_irqs(struct irq_desc *desc, int node, int nr);
extern void clear_kstat_irqs(struct irq_desc *desc);
extern spinlock_t sparse_irq_lock;
@@ -42,6 +42,9 @@ static inline void unregister_handler_proc(unsigned int irq,
extern int irq_select_affinity_usr(unsigned int irq);
+extern void
+irq_set_thread_affinity(struct irq_desc *desc, const struct cpumask *cpumask);
+
/*
* Debugging printout:
*/
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 2734eca5924..aaf5c9d0577 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -80,7 +80,7 @@ int irq_can_set_affinity(unsigned int irq)
return 1;
}
-static void
+void
irq_set_thread_affinity(struct irq_desc *desc, const struct cpumask *cpumask)
{
struct irqaction *action = desc->action;
@@ -109,17 +109,22 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
spin_lock_irqsave(&desc->lock, flags);
#ifdef CONFIG_GENERIC_PENDING_IRQ
- if (desc->status & IRQ_MOVE_PCNTXT)
- desc->chip->set_affinity(irq, cpumask);
+ if (desc->status & IRQ_MOVE_PCNTXT) {
+ if (!desc->chip->set_affinity(irq, cpumask)) {
+ cpumask_copy(desc->affinity, cpumask);
+ irq_set_thread_affinity(desc, cpumask);
+ }
+ }
else {
desc->status |= IRQ_MOVE_PENDING;
cpumask_copy(desc->pending_mask, cpumask);
}
#else
- cpumask_copy(desc->affinity, cpumask);
- desc->chip->set_affinity(irq, cpumask);
+ if (!desc->chip->set_affinity(irq, cpumask)) {
+ cpumask_copy(desc->affinity, cpumask);
+ irq_set_thread_affinity(desc, cpumask);
+ }
#endif
- irq_set_thread_affinity(desc, cpumask);
desc->status |= IRQ_AFFINITY_SET;
spin_unlock_irqrestore(&desc->lock, flags);
return 0;
diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c
index e05ad9be43b..cfe767ca154 100644
--- a/kernel/irq/migration.c
+++ b/kernel/irq/migration.c
@@ -1,5 +1,8 @@
#include <linux/irq.h>
+#include <linux/interrupt.h>
+
+#include "internals.h"
void move_masked_irq(int irq)
{
@@ -39,11 +42,12 @@ void move_masked_irq(int irq)
* masking the irqs.
*/
if (likely(cpumask_any_and(desc->pending_mask, cpu_online_mask)
- < nr_cpu_ids)) {
- cpumask_and(desc->affinity,
- desc->pending_mask, cpu_online_mask);
- desc->chip->set_affinity(irq, desc->affinity);
- }
+ < nr_cpu_ids))
+ if (!desc->chip->set_affinity(irq, desc->pending_mask)) {
+ cpumask_copy(desc->affinity, desc->pending_mask);
+ irq_set_thread_affinity(desc, desc->pending_mask);
+ }
+
cpumask_clear(desc->pending_mask);
}
diff --git a/kernel/irq/numa_migrate.c b/kernel/irq/numa_migrate.c
index 44bbdcbaf8d..2f69bee57bf 100644
--- a/kernel/irq/numa_migrate.c
+++ b/kernel/irq/numa_migrate.c
@@ -15,9 +15,9 @@
static void init_copy_kstat_irqs(struct irq_desc *old_desc,
struct irq_desc *desc,
- int cpu, int nr)
+ int node, int nr)
{
- init_kstat_irqs(desc, cpu, nr);
+ init_kstat_irqs(desc, node, nr);
if (desc->kstat_irqs != old_desc->kstat_irqs)
memcpy(desc->kstat_irqs, old_desc->kstat_irqs,
@@ -34,20 +34,20 @@ static void free_kstat_irqs(struct irq_desc *old_desc, struct irq_desc *desc)
}
static bool init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
- struct irq_desc *desc, int cpu)
+ struct irq_desc *desc, int node)
{
memcpy(desc, old_desc, sizeof(struct irq_desc));
- if (!init_alloc_desc_masks(desc, cpu, false)) {
+ if (!alloc_desc_masks(desc, node, false)) {
printk(KERN_ERR "irq %d: can not get new irq_desc cpumask "
"for migration.\n", irq);
return false;
}
spin_lock_init(&desc->lock);
- desc->cpu = cpu;
+ desc->node = node;
lockdep_set_class(&desc->lock, &irq_desc_lock_class);
- init_copy_kstat_irqs(old_desc, desc, cpu, nr_cpu_ids);
+ init_copy_kstat_irqs(old_desc, desc, node, nr_cpu_ids);
init_copy_desc_masks(old_desc, desc);
- arch_init_copy_chip_data(old_desc, desc, cpu);
+ arch_init_copy_chip_data(old_desc, desc, node);
return true;
}
@@ -59,12 +59,11 @@ static void free_one_irq_desc(struct irq_desc *old_desc, struct irq_desc *desc)
}
static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
- int cpu)
+ int node)
{
struct irq_desc *desc;
unsigned int irq;
unsigned long flags;
- int node;
irq = old_desc->irq;
@@ -76,7 +75,6 @@ static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
if (desc && old_desc != desc)
goto out_unlock;
- node = cpu_to_node(cpu);
desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
if (!desc) {
printk(KERN_ERR "irq %d: can not get new irq_desc "
@@ -85,7 +83,7 @@ static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
desc = old_desc;
goto out_unlock;
}
- if (!init_copy_one_irq_desc(irq, old_desc, desc, cpu)) {
+ if (!init_copy_one_irq_desc(irq, old_desc, desc, node)) {
/* still use old one */
kfree(desc);
desc = old_desc;
@@ -97,9 +95,7 @@ static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
/* free the old one */
free_one_irq_desc(old_desc, desc);
- spin_unlock(&old_desc->lock);
kfree(old_desc);
- spin_lock(&desc->lock);
return desc;
@@ -109,24 +105,14 @@ out_unlock:
return desc;
}
-struct irq_desc *move_irq_desc(struct irq_desc *desc, int cpu)
+struct irq_desc *move_irq_desc(struct irq_desc *desc, int node)
{
- int old_cpu;
- int node, old_node;
-
/* those all static, do move them */
if (desc->irq < NR_IRQS_LEGACY)
return desc;
- old_cpu = desc->cpu;
- if (old_cpu != cpu) {
- node = cpu_to_node(cpu);
- old_node = cpu_to_node(old_cpu);
- if (old_node != node)
- desc = __real_move_irq_desc(desc, cpu);
- else
- desc->cpu = cpu;
- }
+ if (desc->node != node)
+ desc = __real_move_irq_desc(desc, node);
return desc;
}
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 5a758c6e495..e4983770913 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1451,7 +1451,6 @@ int kernel_kexec(void)
error = device_suspend(PMSG_FREEZE);
if (error)
goto Resume_console;
- device_pm_lock();
/* At this point, device_suspend() has been called,
* but *not* device_power_down(). We *must*
* device_power_down() now. Otherwise, drivers for
@@ -1489,7 +1488,6 @@ int kernel_kexec(void)
enable_nonboot_cpus();
device_power_up(PMSG_RESTORE);
Resume_devices:
- device_pm_unlock();
device_resume(PMSG_RESTORE);
Resume_console:
resume_console();
diff --git a/kernel/kgdb.c b/kernel/kgdb.c
index e4dcfb2272a..9147a3190c9 100644
--- a/kernel/kgdb.c
+++ b/kernel/kgdb.c
@@ -1583,8 +1583,8 @@ static void sysrq_handle_gdb(int key, struct tty_struct *tty)
static struct sysrq_key_op sysrq_gdb_op = {
.handler = sysrq_handle_gdb,
- .help_msg = "Gdb",
- .action_msg = "GDB",
+ .help_msg = "debug(G)",
+ .action_msg = "DEBUG",
};
#endif
diff --git a/kernel/kmod.c b/kernel/kmod.c
index b750675251e..7e95bedb2bf 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -370,8 +370,10 @@ struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
sub_info->argv = argv;
sub_info->envp = envp;
sub_info->cred = prepare_usermodehelper_creds();
- if (!sub_info->cred)
+ if (!sub_info->cred) {
+ kfree(sub_info);
return NULL;
+ }
out:
return sub_info;
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index a5e74ddee0e..c0fa54b276d 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -319,6 +319,22 @@ struct kprobe __kprobes *get_kprobe(void *addr)
return NULL;
}
+/* Arm a kprobe with text_mutex */
+static void __kprobes arm_kprobe(struct kprobe *kp)
+{
+ mutex_lock(&text_mutex);
+ arch_arm_kprobe(kp);
+ mutex_unlock(&text_mutex);
+}
+
+/* Disarm a kprobe with text_mutex */
+static void __kprobes disarm_kprobe(struct kprobe *kp)
+{
+ mutex_lock(&text_mutex);
+ arch_disarm_kprobe(kp);
+ mutex_unlock(&text_mutex);
+}
+
/*
* Aggregate handlers for multiple kprobes support - these handlers
* take care of invoking the individual kprobe handlers on p->list
@@ -538,7 +554,7 @@ static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p)
ap->flags &= ~KPROBE_FLAG_DISABLED;
if (!kprobes_all_disarmed)
/* Arm the breakpoint again. */
- arch_arm_kprobe(ap);
+ arm_kprobe(ap);
}
return 0;
}
@@ -789,11 +805,8 @@ static int __kprobes __unregister_kprobe_top(struct kprobe *p)
* enabled and not gone - otherwise, the breakpoint would
* already have been removed. We save on flushing icache.
*/
- if (!kprobes_all_disarmed && !kprobe_disabled(old_p)) {
- mutex_lock(&text_mutex);
- arch_disarm_kprobe(p);
- mutex_unlock(&text_mutex);
- }
+ if (!kprobes_all_disarmed && !kprobe_disabled(old_p))
+ disarm_kprobe(p);
hlist_del_rcu(&old_p->hlist);
} else {
if (p->break_handler && !kprobe_gone(p))
@@ -810,7 +823,7 @@ noclean:
if (!kprobe_disabled(old_p)) {
try_to_disable_aggr_kprobe(old_p);
if (!kprobes_all_disarmed && kprobe_disabled(old_p))
- arch_disarm_kprobe(old_p);
+ disarm_kprobe(old_p);
}
}
return 0;
@@ -1364,7 +1377,7 @@ int __kprobes disable_kprobe(struct kprobe *kp)
try_to_disable_aggr_kprobe(p);
if (!kprobes_all_disarmed && kprobe_disabled(p))
- arch_disarm_kprobe(p);
+ disarm_kprobe(p);
out:
mutex_unlock(&kprobe_mutex);
return ret;
@@ -1393,7 +1406,7 @@ int __kprobes enable_kprobe(struct kprobe *kp)
}
if (!kprobes_all_disarmed && kprobe_disabled(p))
- arch_arm_kprobe(p);
+ arm_kprobe(p);
p->flags &= ~KPROBE_FLAG_DISABLED;
if (p != kp)
diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h
index a2cc7e9a6e8..699a2ac3a0d 100644
--- a/kernel/lockdep_internals.h
+++ b/kernel/lockdep_internals.h
@@ -54,9 +54,9 @@ enum {
* table (if it's not there yet), and we check it for lock order
* conflicts and deadlocks.
*/
-#define MAX_LOCKDEP_ENTRIES 8192UL
+#define MAX_LOCKDEP_ENTRIES 16384UL
-#define MAX_LOCKDEP_CHAINS_BITS 14
+#define MAX_LOCKDEP_CHAINS_BITS 15
#define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)
#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
diff --git a/kernel/mutex.c b/kernel/mutex.c
index 507cf2b5e9f..e5cc0cd28d5 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -249,7 +249,9 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
/* didnt get the lock, go to sleep: */
spin_unlock_mutex(&lock->wait_lock, flags);
- __schedule();
+ preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
spin_lock_mutex(&lock->wait_lock, flags);
}
@@ -471,5 +473,28 @@ int __sched mutex_trylock(struct mutex *lock)
return ret;
}
-
EXPORT_SYMBOL(mutex_trylock);
+
+/**
+ * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0
+ * @cnt: the atomic which we are to dec
+ * @lock: the mutex to return holding if we dec to 0
+ *
+ * return true and hold lock if we dec to 0, return false otherwise
+ */
+int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock)
+{
+ /* dec if we can't possibly hit 0 */
+ if (atomic_add_unless(cnt, -1, 1))
+ return 0;
+ /* we might hit 0, so take the lock */
+ mutex_lock(lock);
+ if (!atomic_dec_and_test(cnt)) {
+ /* when we actually did the dec, we didn't hit 0 */
+ mutex_unlock(lock);
+ return 0;
+ }
+ /* we hit 0, and we hold the lock */
+ return 1;
+}
+EXPORT_SYMBOL(atomic_dec_and_mutex_lock);
diff --git a/kernel/panic.c b/kernel/panic.c
index 3dcaa166135..984b3ecbd72 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -340,34 +340,46 @@ void oops_exit(void)
}
#ifdef WANT_WARN_ON_SLOWPATH
-void warn_slowpath(const char *file, int line, const char *fmt, ...)
-{
+struct slowpath_args {
+ const char *fmt;
va_list args;
- char function[KSYM_SYMBOL_LEN];
- unsigned long caller = (unsigned long)__builtin_return_address(0);
- const char *board;
+};
- sprint_symbol(function, caller);
+static void warn_slowpath_common(const char *file, int line, void *caller, struct slowpath_args *args)
+{
+ const char *board;
printk(KERN_WARNING "------------[ cut here ]------------\n");
- printk(KERN_WARNING "WARNING: at %s:%d %s()\n", file,
- line, function);
+ printk(KERN_WARNING "WARNING: at %s:%d %pS()\n", file, line, caller);
board = dmi_get_system_info(DMI_PRODUCT_NAME);
if (board)
printk(KERN_WARNING "Hardware name: %s\n", board);
- if (fmt) {
- va_start(args, fmt);
- vprintk(fmt, args);
- va_end(args);
- }
+ if (args)
+ vprintk(args->fmt, args->args);
print_modules();
dump_stack();
print_oops_end_marker();
add_taint(TAINT_WARN);
}
-EXPORT_SYMBOL(warn_slowpath);
+
+void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
+{
+ struct slowpath_args args;
+
+ args.fmt = fmt;
+ va_start(args.args, fmt);
+ warn_slowpath_common(file, line, __builtin_return_address(0), &args);
+ va_end(args.args);
+}
+EXPORT_SYMBOL(warn_slowpath_fmt);
+
+void warn_slowpath_null(const char *file, int line)
+{
+ warn_slowpath_common(file, line, __builtin_return_address(0), NULL);
+}
+EXPORT_SYMBOL(warn_slowpath_null);
#endif
#ifdef CONFIG_CC_STACKPROTECTOR
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index c9dcf98b446..bece7c0b67b 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -1420,19 +1420,19 @@ void run_posix_cpu_timers(struct task_struct *tsk)
* timer call will interfere.
*/
list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) {
- int firing;
+ int cpu_firing;
+
spin_lock(&timer->it_lock);
list_del_init(&timer->it.cpu.entry);
- firing = timer->it.cpu.firing;
+ cpu_firing = timer->it.cpu.firing;
timer->it.cpu.firing = 0;
/*
* The firing flag is -1 if we collided with a reset
* of the timer, which already reported this
* almost-firing as an overrun. So don't generate an event.
*/
- if (likely(firing >= 0)) {
+ if (likely(cpu_firing >= 0))
cpu_timer_fire(timer);
- }
spin_unlock(&timer->it_lock);
}
}
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index e71ca9cd81b..5cb080e7eeb 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -215,8 +215,6 @@ static int create_image(int platform_mode)
if (error)
return error;
- device_pm_lock();
-
/* At this point, device_suspend() has been called, but *not*
* device_power_down(). We *must* call device_power_down() now.
* Otherwise, drivers for some devices (e.g. interrupt controllers)
@@ -227,7 +225,7 @@ static int create_image(int platform_mode)
if (error) {
printk(KERN_ERR "PM: Some devices failed to power down, "
"aborting hibernation\n");
- goto Unlock;
+ return error;
}
error = platform_pre_snapshot(platform_mode);
@@ -241,9 +239,9 @@ static int create_image(int platform_mode)
local_irq_disable();
- sysdev_suspend(PMSG_FREEZE);
+ error = sysdev_suspend(PMSG_FREEZE);
if (error) {
- printk(KERN_ERR "PM: Some devices failed to power down, "
+ printk(KERN_ERR "PM: Some system devices failed to power down, "
"aborting hibernation\n");
goto Enable_irqs;
}
@@ -280,9 +278,6 @@ static int create_image(int platform_mode)
device_power_up(in_suspend ?
(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
- Unlock:
- device_pm_unlock();
-
return error;
}
@@ -344,13 +339,11 @@ static int resume_target_kernel(bool platform_mode)
{
int error;
- device_pm_lock();
-
error = device_power_down(PMSG_QUIESCE);
if (error) {
printk(KERN_ERR "PM: Some devices failed to power down, "
"aborting resume\n");
- goto Unlock;
+ return error;
}
error = platform_pre_restore(platform_mode);
@@ -403,9 +396,6 @@ static int resume_target_kernel(bool platform_mode)
device_power_up(PMSG_RECOVER);
- Unlock:
- device_pm_unlock();
-
return error;
}
@@ -464,11 +454,9 @@ int hibernation_platform_enter(void)
goto Resume_devices;
}
- device_pm_lock();
-
error = device_power_down(PMSG_HIBERNATE);
if (error)
- goto Unlock;
+ goto Resume_devices;
error = hibernation_ops->prepare();
if (error)
@@ -493,9 +481,6 @@ int hibernation_platform_enter(void)
device_power_up(PMSG_RESTORE);
- Unlock:
- device_pm_unlock();
-
Resume_devices:
entering_platform_hibernation = false;
device_resume(PMSG_RESTORE);
diff --git a/kernel/power/main.c b/kernel/power/main.c
index f99ed6a75ea..868028280d1 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -289,12 +289,10 @@ static int suspend_enter(suspend_state_t state)
{
int error;
- device_pm_lock();
-
if (suspend_ops->prepare) {
error = suspend_ops->prepare();
if (error)
- goto Done;
+ return error;
}
error = device_power_down(PMSG_SUSPEND);
@@ -343,9 +341,6 @@ static int suspend_enter(suspend_state_t state)
if (suspend_ops->finish)
suspend_ops->finish();
- Done:
- device_pm_unlock();
-
return error;
}
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 0692ab5a0d6..42c317874cf 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -304,6 +304,8 @@ int ptrace_detach(struct task_struct *child, unsigned int data)
if (child->ptrace) {
child->exit_code = data;
dead = __ptrace_detach(current, child);
+ if (!child->exit_state)
+ wake_up_process(child);
}
write_unlock_irq(&tasklist_lock);
diff --git a/kernel/rcupreempt.c b/kernel/rcupreempt.c
index ce97a4df64d..beb0e659adc 100644
--- a/kernel/rcupreempt.c
+++ b/kernel/rcupreempt.c
@@ -1356,17 +1356,11 @@ static int rcu_sched_grace_period(void *arg)
rcu_ctrlblk.sched_sleep = rcu_sched_sleeping;
spin_unlock_irqrestore(&rcu_ctrlblk.schedlock, flags);
- ret = 0;
+ ret = 0; /* unused */
__wait_event_interruptible(rcu_ctrlblk.sched_wq,
rcu_ctrlblk.sched_sleep != rcu_sched_sleeping,
ret);
- /*
- * Signals would prevent us from sleeping, and we cannot
- * do much with them in any case. So flush them.
- */
- if (ret)
- flush_signals(current);
couldsleepnext = 0;
} while (!kthread_should_stop());
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index d2a372fb0b9..0dccfbba6d2 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1259,31 +1259,44 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)
check_cpu_stall(rsp, rdp);
/* Is the RCU core waiting for a quiescent state from this CPU? */
- if (rdp->qs_pending)
+ if (rdp->qs_pending) {
+ rdp->n_rp_qs_pending++;
return 1;
+ }
/* Does this CPU have callbacks ready to invoke? */
- if (cpu_has_callbacks_ready_to_invoke(rdp))
+ if (cpu_has_callbacks_ready_to_invoke(rdp)) {
+ rdp->n_rp_cb_ready++;
return 1;
+ }
/* Has RCU gone idle with this CPU needing another grace period? */
- if (cpu_needs_another_gp(rsp, rdp))
+ if (cpu_needs_another_gp(rsp, rdp)) {
+ rdp->n_rp_cpu_needs_gp++;
return 1;
+ }
/* Has another RCU grace period completed? */
- if (ACCESS_ONCE(rsp->completed) != rdp->completed) /* outside of lock */
+ if (ACCESS_ONCE(rsp->completed) != rdp->completed) { /* outside lock */
+ rdp->n_rp_gp_completed++;
return 1;
+ }
/* Has a new RCU grace period started? */
- if (ACCESS_ONCE(rsp->gpnum) != rdp->gpnum) /* outside of lock */
+ if (ACCESS_ONCE(rsp->gpnum) != rdp->gpnum) { /* outside lock */
+ rdp->n_rp_gp_started++;
return 1;
+ }
/* Has an RCU GP gone long enough to send resched IPIs &c? */
if (ACCESS_ONCE(rsp->completed) != ACCESS_ONCE(rsp->gpnum) &&
- ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0))
+ ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0)) {
+ rdp->n_rp_need_fqs++;
return 1;
+ }
/* nothing to do */
+ rdp->n_rp_need_nothing++;
return 0;
}
diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c
index 4b1875ba940..fe1dcdbf1ca 100644
--- a/kernel/rcutree_trace.c
+++ b/kernel/rcutree_trace.c
@@ -213,7 +213,63 @@ static struct file_operations rcugp_fops = {
.release = single_release,
};
-static struct dentry *rcudir, *datadir, *datadir_csv, *hierdir, *gpdir;
+static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp)
+{
+ seq_printf(m, "%3d%cnp=%ld "
+ "qsp=%ld cbr=%ld cng=%ld gpc=%ld gps=%ld nf=%ld nn=%ld\n",
+ rdp->cpu,
+ cpu_is_offline(rdp->cpu) ? '!' : ' ',
+ rdp->n_rcu_pending,
+ rdp->n_rp_qs_pending,
+ rdp->n_rp_cb_ready,
+ rdp->n_rp_cpu_needs_gp,
+ rdp->n_rp_gp_completed,
+ rdp->n_rp_gp_started,
+ rdp->n_rp_need_fqs,
+ rdp->n_rp_need_nothing);
+}
+
+static void print_rcu_pendings(struct seq_file *m, struct rcu_state *rsp)
+{
+ int cpu;
+ struct rcu_data *rdp;
+
+ for_each_possible_cpu(cpu) {
+ rdp = rsp->rda[cpu];
+ if (rdp->beenonline)
+ print_one_rcu_pending(m, rdp);
+ }
+}
+
+static int show_rcu_pending(struct seq_file *m, void *unused)
+{
+ seq_puts(m, "rcu:\n");
+ print_rcu_pendings(m, &rcu_state);
+ seq_puts(m, "rcu_bh:\n");
+ print_rcu_pendings(m, &rcu_bh_state);
+ return 0;
+}
+
+static int rcu_pending_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, show_rcu_pending, NULL);
+}
+
+static struct file_operations rcu_pending_fops = {
+ .owner = THIS_MODULE,
+ .open = rcu_pending_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static struct dentry *rcudir;
+static struct dentry *datadir;
+static struct dentry *datadir_csv;
+static struct dentry *gpdir;
+static struct dentry *hierdir;
+static struct dentry *rcu_pendingdir;
+
static int __init rcuclassic_trace_init(void)
{
rcudir = debugfs_create_dir("rcu", NULL);
@@ -238,6 +294,11 @@ static int __init rcuclassic_trace_init(void)
NULL, &rcuhier_fops);
if (!hierdir)
goto free_out;
+
+ rcu_pendingdir = debugfs_create_file("rcu_pending", 0444, rcudir,
+ NULL, &rcu_pending_fops);
+ if (!rcu_pendingdir)
+ goto free_out;
return 0;
free_out:
if (datadir)
@@ -257,6 +318,7 @@ static void __exit rcuclassic_trace_cleanup(void)
debugfs_remove(datadir_csv);
debugfs_remove(gpdir);
debugfs_remove(hierdir);
+ debugfs_remove(rcu_pendingdir);
debugfs_remove(rcudir);
}
diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 69d9cb921ff..820c5af44f3 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -300,7 +300,8 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task,
* assigned pending owner [which might not have taken the
* lock yet]:
*/
-static inline int try_to_steal_lock(struct rt_mutex *lock)
+static inline int try_to_steal_lock(struct rt_mutex *lock,
+ struct task_struct *task)
{
struct task_struct *pendowner = rt_mutex_owner(lock);
struct rt_mutex_waiter *next;
@@ -309,11 +310,11 @@ static inline int try_to_steal_lock(struct rt_mutex *lock)
if (!rt_mutex_owner_pending(lock))
return 0;
- if (pendowner == current)
+ if (pendowner == task)
return 1;
spin_lock_irqsave(&pendowner->pi_lock, flags);
- if (current->prio >= pendowner->prio) {
+ if (task->prio >= pendowner->prio) {
spin_unlock_irqrestore(&pendowner->pi_lock, flags);
return 0;
}
@@ -338,21 +339,21 @@ static inline int try_to_steal_lock(struct rt_mutex *lock)
* We are going to steal the lock and a waiter was
* enqueued on the pending owners pi_waiters queue. So
* we have to enqueue this waiter into
- * current->pi_waiters list. This covers the case,
- * where current is boosted because it holds another
+ * task->pi_waiters list. This covers the case,
+ * where task is boosted because it holds another
* lock and gets unboosted because the booster is
* interrupted, so we would delay a waiter with higher
- * priority as current->normal_prio.
+ * priority as task->normal_prio.
*
* Note: in the rare case of a SCHED_OTHER task changing
* its priority and thus stealing the lock, next->task
- * might be current:
+ * might be task:
*/
- if (likely(next->task != current)) {
- spin_lock_irqsave(&current->pi_lock, flags);
- plist_add(&next->pi_list_entry, &current->pi_waiters);
- __rt_mutex_adjust_prio(current);
- spin_unlock_irqrestore(&current->pi_lock, flags);
+ if (likely(next->task != task)) {
+ spin_lock_irqsave(&task->pi_lock, flags);
+ plist_add(&next->pi_list_entry, &task->pi_waiters);
+ __rt_mutex_adjust_prio(task);
+ spin_unlock_irqrestore(&task->pi_lock, flags);
}
return 1;
}
@@ -389,7 +390,7 @@ static int try_to_take_rt_mutex(struct rt_mutex *lock)
*/
mark_rt_mutex_waiters(lock);
- if (rt_mutex_owner(lock) && !try_to_steal_lock(lock))
+ if (rt_mutex_owner(lock) && !try_to_steal_lock(lock, current))
return 0;
/* We got the lock. */
@@ -411,6 +412,7 @@ static int try_to_take_rt_mutex(struct rt_mutex *lock)
*/
static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
struct rt_mutex_waiter *waiter,
+ struct task_struct *task,
int detect_deadlock)
{
struct task_struct *owner = rt_mutex_owner(lock);
@@ -418,21 +420,21 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
unsigned long flags;
int chain_walk = 0, res;
- spin_lock_irqsave(&current->pi_lock, flags);
- __rt_mutex_adjust_prio(current);
- waiter->task = current;
+ spin_lock_irqsave(&task->pi_lock, flags);
+ __rt_mutex_adjust_prio(task);
+ waiter->task = task;
waiter->lock = lock;
- plist_node_init(&waiter->list_entry, current->prio);
- plist_node_init(&waiter->pi_list_entry, current->prio);
+ plist_node_init(&waiter->list_entry, task->prio);
+ plist_node_init(&waiter->pi_list_entry, task->prio);
/* Get the top priority waiter on the lock */
if (rt_mutex_has_waiters(lock))
top_waiter = rt_mutex_top_waiter(lock);
plist_add(&waiter->list_entry, &lock->wait_list);
- current->pi_blocked_on = waiter;
+ task->pi_blocked_on = waiter;
- spin_unlock_irqrestore(&current->pi_lock, flags);
+ spin_unlock_irqrestore(&task->pi_lock, flags);
if (waiter == rt_mutex_top_waiter(lock)) {
spin_lock_irqsave(&owner->pi_lock, flags);
@@ -460,7 +462,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
spin_unlock(&lock->wait_lock);
res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, waiter,
- current);
+ task);
spin_lock(&lock->wait_lock);
@@ -605,37 +607,25 @@ void rt_mutex_adjust_pi(struct task_struct *task)
rt_mutex_adjust_prio_chain(task, 0, NULL, NULL, task);
}
-/*
- * Slow path lock function:
+/**
+ * __rt_mutex_slowlock() - Perform the wait-wake-try-to-take loop
+ * @lock: the rt_mutex to take
+ * @state: the state the task should block in (TASK_INTERRUPTIBLE
+ * or TASK_UNINTERRUPTIBLE)
+ * @timeout: the pre-initialized and started timer, or NULL for none
+ * @waiter: the pre-initialized rt_mutex_waiter
+ * @detect_deadlock: passed to task_blocks_on_rt_mutex
+ *
+ * lock->wait_lock must be held by the caller.
*/
static int __sched
-rt_mutex_slowlock(struct rt_mutex *lock, int state,
- struct hrtimer_sleeper *timeout,
- int detect_deadlock)
+__rt_mutex_slowlock(struct rt_mutex *lock, int state,
+ struct hrtimer_sleeper *timeout,
+ struct rt_mutex_waiter *waiter,
+ int detect_deadlock)
{
- struct rt_mutex_waiter waiter;
int ret = 0;
- debug_rt_mutex_init_waiter(&waiter);
- waiter.task = NULL;
-
- spin_lock(&lock->wait_lock);
-
- /* Try to acquire the lock again: */
- if (try_to_take_rt_mutex(lock)) {
- spin_unlock(&lock->wait_lock);
- return 0;
- }
-
- set_current_state(state);
-
- /* Setup the timer, when timeout != NULL */
- if (unlikely(timeout)) {
- hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
- if (!hrtimer_active(&timeout->timer))
- timeout->task = NULL;
- }
-
for (;;) {
/* Try to acquire the lock: */
if (try_to_take_rt_mutex(lock))
@@ -656,19 +646,19 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
}
/*
- * waiter.task is NULL the first time we come here and
+ * waiter->task is NULL the first time we come here and
* when we have been woken up by the previous owner
* but the lock got stolen by a higher prio task.
*/
- if (!waiter.task) {
- ret = task_blocks_on_rt_mutex(lock, &waiter,
+ if (!waiter->task) {
+ ret = task_blocks_on_rt_mutex(lock, waiter, current,
detect_deadlock);
/*
* If we got woken up by the owner then start loop
* all over without going into schedule to try
* to get the lock now:
*/
- if (unlikely(!waiter.task)) {
+ if (unlikely(!waiter->task)) {
/*
* Reset the return value. We might
* have returned with -EDEADLK and the
@@ -684,15 +674,52 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
spin_unlock(&lock->wait_lock);
- debug_rt_mutex_print_deadlock(&waiter);
+ debug_rt_mutex_print_deadlock(waiter);
- if (waiter.task)
+ if (waiter->task)
schedule_rt_mutex(lock);
spin_lock(&lock->wait_lock);
set_current_state(state);
}
+ return ret;
+}
+
+/*
+ * Slow path lock function:
+ */
+static int __sched
+rt_mutex_slowlock(struct rt_mutex *lock, int state,
+ struct hrtimer_sleeper *timeout,
+ int detect_deadlock)
+{
+ struct rt_mutex_waiter waiter;
+ int ret = 0;
+
+ debug_rt_mutex_init_waiter(&waiter);
+ waiter.task = NULL;
+
+ spin_lock(&lock->wait_lock);
+
+ /* Try to acquire the lock again: */
+ if (try_to_take_rt_mutex(lock)) {
+ spin_unlock(&lock->wait_lock);
+ return 0;
+ }
+
+ set_current_state(state);
+
+ /* Setup the timer, when timeout != NULL */
+ if (unlikely(timeout)) {
+ hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
+ if (!hrtimer_active(&timeout->timer))
+ timeout->task = NULL;
+ }
+
+ ret = __rt_mutex_slowlock(lock, state, timeout, &waiter,
+ detect_deadlock);
+
set_current_state(TASK_RUNNING);
if (unlikely(waiter.task))
@@ -864,9 +891,9 @@ int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock,
EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);
/**
- * rt_mutex_lock_interruptible_ktime - lock a rt_mutex interruptible
- * the timeout structure is provided
- * by the caller
+ * rt_mutex_timed_lock - lock a rt_mutex interruptible
+ * the timeout structure is provided
+ * by the caller
*
* @lock: the rt_mutex to be locked
* @timeout: timeout structure or NULL (no timeout)
@@ -913,7 +940,7 @@ void __sched rt_mutex_unlock(struct rt_mutex *lock)
}
EXPORT_SYMBOL_GPL(rt_mutex_unlock);
-/***
+/**
* rt_mutex_destroy - mark a mutex unusable
* @lock: the mutex to be destroyed
*
@@ -986,6 +1013,59 @@ void rt_mutex_proxy_unlock(struct rt_mutex *lock,
}
/**
+ * rt_mutex_start_proxy_lock() - Start lock acquisition for another task
+ * @lock: the rt_mutex to take
+ * @waiter: the pre-initialized rt_mutex_waiter
+ * @task: the task to prepare
+ * @detect_deadlock: perform deadlock detection (1) or not (0)
+ *
+ * Returns:
+ * 0 - task blocked on lock
+ * 1 - acquired the lock for task, caller should wake it up
+ * <0 - error
+ *
+ * Special API call for FUTEX_REQUEUE_PI support.
+ */
+int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
+ struct rt_mutex_waiter *waiter,
+ struct task_struct *task, int detect_deadlock)
+{
+ int ret;
+
+ spin_lock(&lock->wait_lock);
+
+ mark_rt_mutex_waiters(lock);
+
+ if (!rt_mutex_owner(lock) || try_to_steal_lock(lock, task)) {
+ /* We got the lock for task. */
+ debug_rt_mutex_lock(lock);
+
+ rt_mutex_set_owner(lock, task, 0);
+
+ rt_mutex_deadlock_account_lock(lock, task);
+ return 1;
+ }
+
+ ret = task_blocks_on_rt_mutex(lock, waiter, task, detect_deadlock);
+
+
+ if (ret && !waiter->task) {
+ /*
+ * Reset the return value. We might have
+ * returned with -EDEADLK and the owner
+ * released the lock while we were walking the
+ * pi chain. Let the waiter sort it out.
+ */
+ ret = 0;
+ }
+ spin_unlock(&lock->wait_lock);
+
+ debug_rt_mutex_print_deadlock(waiter);
+
+ return ret;
+}
+
+/**
* rt_mutex_next_owner - return the next owner of the lock
*
* @lock: the rt lock query
@@ -1004,3 +1084,57 @@ struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock)
return rt_mutex_top_waiter(lock)->task;
}
+
+/**
+ * rt_mutex_finish_proxy_lock() - Complete lock acquisition
+ * @lock: the rt_mutex we were woken on
+ * @to: the timeout, null if none. hrtimer should already have
+ * been started.
+ * @waiter: the pre-initialized rt_mutex_waiter
+ * @detect_deadlock: perform deadlock detection (1) or not (0)
+ *
+ * Complete the lock acquisition started our behalf by another thread.
+ *
+ * Returns:
+ * 0 - success
+ * <0 - error, one of -EINTR, -ETIMEDOUT, or -EDEADLK
+ *
+ * Special API call for PI-futex requeue support
+ */
+int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
+ struct hrtimer_sleeper *to,
+ struct rt_mutex_waiter *waiter,
+ int detect_deadlock)
+{
+ int ret;
+
+ spin_lock(&lock->wait_lock);
+
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter,
+ detect_deadlock);
+
+ set_current_state(TASK_RUNNING);
+
+ if (unlikely(waiter->task))
+ remove_waiter(lock, waiter);
+
+ /*
+ * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might
+ * have to fix that up.
+ */
+ fixup_rt_mutex_waiters(lock);
+
+ spin_unlock(&lock->wait_lock);
+
+ /*
+ * Readjust priority, when we did not get the lock. We might have been
+ * the pending owner and boosted. Since we did not take the lock, the
+ * PI boost has to go.
+ */
+ if (unlikely(ret))
+ rt_mutex_adjust_prio(current);
+
+ return ret;
+}
diff --git a/kernel/rtmutex_common.h b/kernel/rtmutex_common.h
index e124bf5800e..97a2f81866a 100644
--- a/kernel/rtmutex_common.h
+++ b/kernel/rtmutex_common.h
@@ -120,6 +120,14 @@ extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
struct task_struct *proxy_owner);
extern void rt_mutex_proxy_unlock(struct rt_mutex *lock,
struct task_struct *proxy_owner);
+extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
+ struct rt_mutex_waiter *waiter,
+ struct task_struct *task,
+ int detect_deadlock);
+extern int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
+ struct hrtimer_sleeper *to,
+ struct rt_mutex_waiter *waiter,
+ int detect_deadlock);
#ifdef CONFIG_DEBUG_RT_MUTEXES
# include "rtmutex-debug.h"
diff --git a/kernel/sched.c b/kernel/sched.c
index b902e587a3a..076e403b9c8 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -630,6 +630,10 @@ struct rq {
struct list_head migration_queue;
#endif
+ /* calc_load related fields */
+ unsigned long calc_load_update;
+ long calc_load_active;
+
#ifdef CONFIG_SCHED_HRTICK
#ifdef CONFIG_SMP
int hrtick_csd_pending;
@@ -1728,6 +1732,8 @@ static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares)
}
#endif
+static void calc_load_account_active(struct rq *this_rq);
+
#include "sched_stats.h"
#include "sched_idletask.c"
#include "sched_fair.c"
@@ -2458,6 +2464,17 @@ out:
return success;
}
+/**
+ * wake_up_process - Wake up a specific process
+ * @p: The process to be woken up.
+ *
+ * Attempt to wake up the nominated process and move it to the set of runnable
+ * processes. Returns 1 if the process was woken up, 0 if it was already
+ * running.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
int wake_up_process(struct task_struct *p)
{
return try_to_wake_up(p, TASK_ALL, 0);
@@ -2766,7 +2783,7 @@ context_switch(struct rq *rq, struct task_struct *prev,
* combine the page table reload and the switch backend into
* one hypercall.
*/
- arch_enter_lazy_cpu_mode();
+ arch_start_context_switch(prev);
if (unlikely(!mm)) {
next->active_mm = oldmm;
@@ -2856,19 +2873,72 @@ unsigned long nr_iowait(void)
return sum;
}
-unsigned long nr_active(void)
+/* Variables and functions for calc_load */
+static atomic_long_t calc_load_tasks;
+static unsigned long calc_load_update;
+unsigned long avenrun[3];
+EXPORT_SYMBOL(avenrun);
+
+/**
+ * get_avenrun - get the load average array
+ * @loads: pointer to dest load array
+ * @offset: offset to add
+ * @shift: shift count to shift the result left
+ *
+ * These values are estimates at best, so no need for locking.
+ */
+void get_avenrun(unsigned long *loads, unsigned long offset, int shift)
{
- unsigned long i, running = 0, uninterruptible = 0;
+ loads[0] = (avenrun[0] + offset) << shift;
+ loads[1] = (avenrun[1] + offset) << shift;
+ loads[2] = (avenrun[2] + offset) << shift;
+}
- for_each_online_cpu(i) {
- running += cpu_rq(i)->nr_running;
- uninterruptible += cpu_rq(i)->nr_uninterruptible;
- }
+static unsigned long
+calc_load(unsigned long load, unsigned long exp, unsigned long active)
+{
+ load *= exp;
+ load += active * (FIXED_1 - exp);
+ return load >> FSHIFT;
+}
- if (unlikely((long)uninterruptible < 0))
- uninterruptible = 0;
+/*
+ * calc_load - update the avenrun load estimates 10 ticks after the
+ * CPUs have updated calc_load_tasks.
+ */
+void calc_global_load(void)
+{
+ unsigned long upd = calc_load_update + 10;
+ long active;
+
+ if (time_before(jiffies, upd))
+ return;
+
+ active = atomic_long_read(&calc_load_tasks);
+ active = active > 0 ? active * FIXED_1 : 0;
- return running + uninterruptible;
+ avenrun[0] = calc_load(avenrun[0], EXP_1, active);
+ avenrun[1] = calc_load(avenrun[1], EXP_5, active);
+ avenrun[2] = calc_load(avenrun[2], EXP_15, active);
+
+ calc_load_update += LOAD_FREQ;
+}
+
+/*
+ * Either called from update_cpu_load() or from a cpu going idle
+ */
+static void calc_load_account_active(struct rq *this_rq)
+{
+ long nr_active, delta;
+
+ nr_active = this_rq->nr_running;
+ nr_active += (long) this_rq->nr_uninterruptible;
+
+ if (nr_active != this_rq->calc_load_active) {
+ delta = nr_active - this_rq->calc_load_active;
+ this_rq->calc_load_active = nr_active;
+ atomic_long_add(delta, &calc_load_tasks);
+ }
}
/*
@@ -2899,6 +2969,11 @@ static void update_cpu_load(struct rq *this_rq)
new_load += scale-1;
this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i;
}
+
+ if (time_after_eq(jiffies, this_rq->calc_load_update)) {
+ this_rq->calc_load_update += LOAD_FREQ;
+ calc_load_account_active(this_rq);
+ }
}
#ifdef CONFIG_SMP
@@ -4240,10 +4315,126 @@ static void active_load_balance(struct rq *busiest_rq, int busiest_cpu)
static struct {
atomic_t load_balancer;
cpumask_var_t cpu_mask;
+ cpumask_var_t ilb_grp_nohz_mask;
} nohz ____cacheline_aligned = {
.load_balancer = ATOMIC_INIT(-1),
};
+#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
+/**
+ * lowest_flag_domain - Return lowest sched_domain containing flag.
+ * @cpu: The cpu whose lowest level of sched domain is to
+ * be returned.
+ * @flag: The flag to check for the lowest sched_domain
+ * for the given cpu.
+ *
+ * Returns the lowest sched_domain of a cpu which contains the given flag.
+ */
+static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
+{
+ struct sched_domain *sd;
+
+ for_each_domain(cpu, sd)
+ if (sd && (sd->flags & flag))
+ break;
+
+ return sd;
+}
+
+/**
+ * for_each_flag_domain - Iterates over sched_domains containing the flag.
+ * @cpu: The cpu whose domains we're iterating over.
+ * @sd: variable holding the value of the power_savings_sd
+ * for cpu.
+ * @flag: The flag to filter the sched_domains to be iterated.
+ *
+ * Iterates over all the scheduler domains for a given cpu that has the 'flag'
+ * set, starting from the lowest sched_domain to the highest.
+ */
+#define for_each_flag_domain(cpu, sd, flag) \
+ for (sd = lowest_flag_domain(cpu, flag); \
+ (sd && (sd->flags & flag)); sd = sd->parent)
+
+/**
+ * is_semi_idle_group - Checks if the given sched_group is semi-idle.
+ * @ilb_group: group to be checked for semi-idleness
+ *
+ * Returns: 1 if the group is semi-idle. 0 otherwise.
+ *
+ * We define a sched_group to be semi idle if it has atleast one idle-CPU
+ * and atleast one non-idle CPU. This helper function checks if the given
+ * sched_group is semi-idle or not.
+ */
+static inline int is_semi_idle_group(struct sched_group *ilb_group)
+{
+ cpumask_and(nohz.ilb_grp_nohz_mask, nohz.cpu_mask,
+ sched_group_cpus(ilb_group));
+
+ /*
+ * A sched_group is semi-idle when it has atleast one busy cpu
+ * and atleast one idle cpu.
+ */
+ if (cpumask_empty(nohz.ilb_grp_nohz_mask))
+ return 0;
+
+ if (cpumask_equal(nohz.ilb_grp_nohz_mask, sched_group_cpus(ilb_group)))
+ return 0;
+
+ return 1;
+}
+/**
+ * find_new_ilb - Finds the optimum idle load balancer for nomination.
+ * @cpu: The cpu which is nominating a new idle_load_balancer.
+ *
+ * Returns: Returns the id of the idle load balancer if it exists,
+ * Else, returns >= nr_cpu_ids.
+ *
+ * This algorithm picks the idle load balancer such that it belongs to a
+ * semi-idle powersavings sched_domain. The idea is to try and avoid
+ * completely idle packages/cores just for the purpose of idle load balancing
+ * when there are other idle cpu's which are better suited for that job.
+ */
+static int find_new_ilb(int cpu)
+{
+ struct sched_domain *sd;
+ struct sched_group *ilb_group;
+
+ /*
+ * Have idle load balancer selection from semi-idle packages only
+ * when power-aware load balancing is enabled
+ */
+ if (!(sched_smt_power_savings || sched_mc_power_savings))
+ goto out_done;
+
+ /*
+ * Optimize for the case when we have no idle CPUs or only one
+ * idle CPU. Don't walk the sched_domain hierarchy in such cases
+ */
+ if (cpumask_weight(nohz.cpu_mask) < 2)
+ goto out_done;
+
+ for_each_flag_domain(cpu, sd, SD_POWERSAVINGS_BALANCE) {
+ ilb_group = sd->groups;
+
+ do {
+ if (is_semi_idle_group(ilb_group))
+ return cpumask_first(nohz.ilb_grp_nohz_mask);
+
+ ilb_group = ilb_group->next;
+
+ } while (ilb_group != sd->groups);
+ }
+
+out_done:
+ return cpumask_first(nohz.cpu_mask);
+}
+#else /* (CONFIG_SCHED_MC || CONFIG_SCHED_SMT) */
+static inline int find_new_ilb(int call_cpu)
+{
+ return cpumask_first(nohz.cpu_mask);
+}
+#endif
+
/*
* This routine will try to nominate the ilb (idle load balancing)
* owner among the cpus whose ticks are stopped. ilb owner will do the idle
@@ -4298,8 +4489,24 @@ int select_nohz_load_balancer(int stop_tick)
/* make me the ilb owner */
if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1)
return 1;
- } else if (atomic_read(&nohz.load_balancer) == cpu)
+ } else if (atomic_read(&nohz.load_balancer) == cpu) {
+ int new_ilb;
+
+ if (!(sched_smt_power_savings ||
+ sched_mc_power_savings))
+ return 1;
+ /*
+ * Check to see if there is a more power-efficient
+ * ilb.
+ */
+ new_ilb = find_new_ilb(cpu);
+ if (new_ilb < nr_cpu_ids && new_ilb != cpu) {
+ atomic_set(&nohz.load_balancer, -1);
+ resched_cpu(new_ilb);
+ return 0;
+ }
return 1;
+ }
} else {
if (!cpumask_test_cpu(cpu, nohz.cpu_mask))
return 0;
@@ -4468,15 +4675,7 @@ static inline void trigger_load_balance(struct rq *rq, int cpu)
}
if (atomic_read(&nohz.load_balancer) == -1) {
- /*
- * simple selection for now: Nominate the
- * first cpu in the nohz list to be the next
- * ilb owner.
- *
- * TBD: Traverse the sched domains and nominate
- * the nearest cpu in the nohz.cpu_mask.
- */
- int ilb = cpumask_first(nohz.cpu_mask);
+ int ilb = find_new_ilb(cpu);
if (ilb < nr_cpu_ids)
resched_cpu(ilb);
@@ -4732,7 +4931,7 @@ void account_process_tick(struct task_struct *p, int user_tick)
if (user_tick)
account_user_time(p, one_jiffy, one_jiffy_scaled);
- else if (p != rq->idle)
+ else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
account_system_time(p, HARDIRQ_OFFSET, one_jiffy,
one_jiffy_scaled);
else
@@ -5007,13 +5206,15 @@ pick_next_task(struct rq *rq)
/*
* schedule() is the main scheduler function.
*/
-asmlinkage void __sched __schedule(void)
+asmlinkage void __sched schedule(void)
{
struct task_struct *prev, *next;
unsigned long *switch_count;
struct rq *rq;
int cpu;
+need_resched:
+ preempt_disable();
cpu = smp_processor_id();
rq = cpu_rq(cpu);
rcu_qsctr_inc(cpu);
@@ -5070,15 +5271,9 @@ need_resched_nonpreemptible:
if (unlikely(reacquire_kernel_lock(current) < 0))
goto need_resched_nonpreemptible;
-}
-asmlinkage void __sched schedule(void)
-{
-need_resched:
- preempt_disable();
- __schedule();
preempt_enable_no_resched();
- if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
+ if (need_resched())
goto need_resched;
}
EXPORT_SYMBOL(schedule);
@@ -5221,7 +5416,7 @@ EXPORT_SYMBOL(default_wake_function);
* started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
* zero in this (rare) case, and we handle it by continuing to scan the queue.
*/
-void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
+static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
int nr_exclusive, int sync, void *key)
{
wait_queue_t *curr, *next;
@@ -5241,6 +5436,9 @@ void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
* @mode: which threads
* @nr_exclusive: how many wake-one or wake-many threads to wake up
* @key: is directly passed to the wakeup function
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
*/
void __wake_up(wait_queue_head_t *q, unsigned int mode,
int nr_exclusive, void *key)
@@ -5279,6 +5477,9 @@ void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
* with each other. This can prevent needless bouncing between CPUs.
*
* On UP it can prevent extra preemption.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
*/
void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
int nr_exclusive, void *key)
@@ -5315,6 +5516,9 @@ EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
* awakened in the same order in which they were queued.
*
* See also complete_all(), wait_for_completion() and related routines.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
*/
void complete(struct completion *x)
{
@@ -5332,6 +5536,9 @@ EXPORT_SYMBOL(complete);
* @x: holds the state of this particular completion
*
* This will wake up all threads waiting on this particular completion event.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
*/
void complete_all(struct completion *x)
{
@@ -6490,8 +6697,9 @@ void sched_show_task(struct task_struct *p)
#ifdef CONFIG_DEBUG_STACK_USAGE
free = stack_not_used(p);
#endif
- printk(KERN_CONT "%5lu %5d %6d\n", free,
- task_pid_nr(p), task_pid_nr(p->real_parent));
+ printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free,
+ task_pid_nr(p), task_pid_nr(p->real_parent),
+ (unsigned long)task_thread_info(p)->flags);
show_stack(p, NULL);
}
@@ -6970,6 +7178,14 @@ static void migrate_dead_tasks(unsigned int dead_cpu)
}
}
+
+/*
+ * remove the tasks which were accounted by rq from calc_load_tasks.
+ */
+static void calc_global_load_remove(struct rq *rq)
+{
+ atomic_long_sub(rq->calc_load_active, &calc_load_tasks);
+}
#endif /* CONFIG_HOTPLUG_CPU */
#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
@@ -7204,6 +7420,8 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
/* Update our root-domain */
rq = cpu_rq(cpu);
spin_lock_irqsave(&rq->lock, flags);
+ rq->calc_load_update = calc_load_update;
+ rq->calc_load_active = 0;
if (rq->rd) {
BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
@@ -7243,7 +7461,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
cpuset_unlock();
migrate_nr_uninterruptible(rq);
BUG_ON(rq->nr_running != 0);
-
+ calc_global_load_remove(rq);
/*
* No need to migrate the tasks: it was best-effort if
* they didn't take sched_hotcpu_mutex. Just wake up
@@ -7753,8 +7971,9 @@ int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
/*
* The cpus mask in sched_group and sched_domain hangs off the end.
- * FIXME: use cpumask_var_t or dynamic percpu alloc to avoid wasting space
- * for nr_cpu_ids < CONFIG_NR_CPUS.
+ *
+ * ( See the the comments in include/linux/sched.h:struct sched_group
+ * and struct sched_domain. )
*/
struct static_sched_group {
struct sched_group sg;
@@ -7875,7 +8094,7 @@ static void init_numa_sched_groups_power(struct sched_group *group_head)
struct sched_domain *sd;
sd = &per_cpu(phys_domains, j).sd;
- if (j != cpumask_first(sched_group_cpus(sd->groups))) {
+ if (j != group_first_cpu(sd->groups)) {
/*
* Only add "power" once for each
* physical package.
@@ -7953,7 +8172,7 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd)
WARN_ON(!sd || !sd->groups);
- if (cpu != cpumask_first(sched_group_cpus(sd->groups)))
+ if (cpu != group_first_cpu(sd->groups))
return;
child = sd->child;
@@ -8938,6 +9157,8 @@ void __init sched_init(void)
rq = cpu_rq(i);
spin_lock_init(&rq->lock);
rq->nr_running = 0;
+ rq->calc_load_active = 0;
+ rq->calc_load_update = jiffies + LOAD_FREQ;
init_cfs_rq(&rq->cfs, rq);
init_rt_rq(&rq->rt, rq);
#ifdef CONFIG_FAIR_GROUP_SCHED
@@ -9045,6 +9266,9 @@ void __init sched_init(void)
* when this runqueue becomes "idle".
*/
init_idle(current, smp_processor_id());
+
+ calc_load_update = jiffies + LOAD_FREQ;
+
/*
* During early bootup we pretend to be a normal task:
*/
@@ -9055,6 +9279,7 @@ void __init sched_init(void)
#ifdef CONFIG_SMP
#ifdef CONFIG_NO_HZ
alloc_bootmem_cpumask_var(&nohz.cpu_mask);
+ alloc_bootmem_cpumask_var(&nohz.ilb_grp_nohz_mask);
#endif
alloc_bootmem_cpumask_var(&cpu_isolated_map);
#endif /* SMP */
@@ -9800,6 +10025,13 @@ static int sched_rt_global_constraints(void)
if (sysctl_sched_rt_period <= 0)
return -EINVAL;
+ /*
+ * There's always some RT tasks in the root group
+ * -- migration, kstopmachine etc..
+ */
+ if (sysctl_sched_rt_runtime == 0)
+ return -EBUSY;
+
spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags);
for_each_possible_cpu(i) {
struct rt_rq *rt_rq = &cpu_rq(i)->rt;
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
index 819f17ac796..e1d16c9a768 100644
--- a/kernel/sched_clock.c
+++ b/kernel/sched_clock.c
@@ -38,7 +38,8 @@
*/
unsigned long long __attribute__((weak)) sched_clock(void)
{
- return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ);
+ return (unsigned long long)(jiffies - INITIAL_JIFFIES)
+ * (NSEC_PER_SEC / HZ);
}
static __read_mostly int sched_clock_running;
diff --git a/kernel/sched_cpupri.c b/kernel/sched_cpupri.c
index cdd3c89574c..344712a5e3e 100644
--- a/kernel/sched_cpupri.c
+++ b/kernel/sched_cpupri.c
@@ -165,7 +165,7 @@ int __init_refok cpupri_init(struct cpupri *cp, bool bootmem)
vec->count = 0;
if (bootmem)
alloc_bootmem_cpumask_var(&vec->mask);
- else if (!alloc_cpumask_var(&vec->mask, GFP_KERNEL))
+ else if (!zalloc_cpumask_var(&vec->mask, GFP_KERNEL))
goto cleanup;
}
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 3816f217f11..5f9650e8fe7 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1487,17 +1487,10 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync)
find_matching_se(&se, &pse);
- while (se) {
- BUG_ON(!pse);
+ BUG_ON(!pse);
- if (wakeup_preempt_entity(se, pse) == 1) {
- resched_task(curr);
- break;
- }
-
- se = parent_entity(se);
- pse = parent_entity(pse);
- }
+ if (wakeup_preempt_entity(se, pse) == 1)
+ resched_task(curr);
}
static struct task_struct *pick_next_task_fair(struct rq *rq)
diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c
index 8a21a2e28c1..499672c10cb 100644
--- a/kernel/sched_idletask.c
+++ b/kernel/sched_idletask.c
@@ -22,7 +22,8 @@ static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int sy
static struct task_struct *pick_next_task_idle(struct rq *rq)
{
schedstat_inc(rq, sched_goidle);
-
+ /* adjust the active tasks as we might go into a long sleep */
+ calc_load_account_active(rq);
return rq->idle;
}
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index f2c66f8f971..9bf0d2a7304 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1591,7 +1591,7 @@ static inline void init_sched_rt_class(void)
unsigned int i;
for_each_possible_cpu(i)
- alloc_cpumask_var_node(&per_cpu(local_cpu_mask, i),
+ zalloc_cpumask_var_node(&per_cpu(local_cpu_mask, i),
GFP_KERNEL, cpu_to_node(i));
}
#endif /* CONFIG_SMP */
diff --git a/kernel/smp.c b/kernel/smp.c
index 858baac568e..ad63d850120 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -52,7 +52,7 @@ hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
- if (!alloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL,
+ if (!zalloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL,
cpu_to_node(cpu)))
return NOTIFY_BAD;
break;
diff --git a/kernel/softirq.c b/kernel/softirq.c
index b525dd34851..f674f332a02 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -828,7 +828,7 @@ int __init __weak arch_early_irq_init(void)
return 0;
}
-int __weak arch_init_chip_data(struct irq_desc *desc, int cpu)
+int __weak arch_init_chip_data(struct irq_desc *desc, int node)
{
return 0;
}
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index e3d2c7dd59b..6a463716ecb 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -101,7 +101,9 @@ static int __maybe_unused one = 1;
static int __maybe_unused two = 2;
static unsigned long one_ul = 1;
static int one_hundred = 100;
-static int one_thousand = 1000;
+
+/* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
+static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
static int maxolduid = 65535;
@@ -729,6 +731,14 @@ static struct ctl_table kern_table[] = {
},
{
.ctl_name = CTL_UNNUMBERED,
+ .procname = "bootloader_version",
+ .data = &bootloader_version,
+ .maxlen = sizeof (int),
+ .mode = 0444,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = CTL_UNNUMBERED,
.procname = "kstack_depth_to_print",
.data = &kstack_depth_to_print,
.maxlen = sizeof(int),
@@ -1006,7 +1016,7 @@ static struct ctl_table vm_table[] = {
.mode = 0644,
.proc_handler = &dirty_bytes_handler,
.strategy = &sysctl_intvec,
- .extra1 = &one_ul,
+ .extra1 = &dirty_bytes_min,
},
{
.procname = "dirty_writeback_centisecs",
@@ -1031,28 +1041,6 @@ static struct ctl_table vm_table[] = {
.proc_handler = &proc_dointvec,
},
{
- .ctl_name = CTL_UNNUMBERED,
- .procname = "nr_pdflush_threads_min",
- .data = &nr_pdflush_threads_min,
- .maxlen = sizeof nr_pdflush_threads_min,
- .mode = 0644 /* read-write */,
- .proc_handler = &proc_dointvec_minmax,
- .strategy = &sysctl_intvec,
- .extra1 = &one,
- .extra2 = &nr_pdflush_threads_max,
- },
- {
- .ctl_name = CTL_UNNUMBERED,
- .procname = "nr_pdflush_threads_max",
- .data = &nr_pdflush_threads_max,
- .maxlen = sizeof nr_pdflush_threads_max,
- .mode = 0644 /* read-write */,
- .proc_handler = &proc_dointvec_minmax,
- .strategy = &sysctl_intvec,
- .extra1 = &nr_pdflush_threads_min,
- .extra2 = &one_thousand,
- },
- {
.ctl_name = VM_SWAPPINESS,
.procname = "swappiness",
.data = &vm_swappiness,
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 21a5ca84951..83c4417b6a3 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -93,7 +93,17 @@ void tick_handle_periodic(struct clock_event_device *dev)
for (;;) {
if (!clockevents_program_event(dev, next, ktime_get()))
return;
- tick_periodic(cpu);
+ /*
+ * Have to be careful here. If we're in oneshot mode,
+ * before we call tick_periodic() in a loop, we need
+ * to be sure we're using a real hardware clocksource.
+ * Otherwise we could get trapped in an infinite
+ * loop, as the tick_periodic() increments jiffies,
+ * when then will increment time, posibly causing
+ * the loop to trigger again and again.
+ */
+ if (timekeeping_valid_for_hres())
+ tick_periodic(cpu);
next = ktime_add(next, tick_period);
}
}
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 687dff49f6e..52a8bf8931f 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -22,7 +22,7 @@
/*
* This read-write spinlock protects us from races in SMP while
- * playing with xtime and avenrun.
+ * playing with xtime.
*/
__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
diff --git a/kernel/timer.c b/kernel/timer.c
index cffffad01c3..a26ed294f93 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1123,47 +1123,6 @@ void update_process_times(int user_tick)
}
/*
- * Nr of active tasks - counted in fixed-point numbers
- */
-static unsigned long count_active_tasks(void)
-{
- return nr_active() * FIXED_1;
-}
-
-/*
- * Hmm.. Changed this, as the GNU make sources (load.c) seems to
- * imply that avenrun[] is the standard name for this kind of thing.
- * Nothing else seems to be standardized: the fractional size etc
- * all seem to differ on different machines.
- *
- * Requires xtime_lock to access.
- */
-unsigned long avenrun[3];
-
-EXPORT_SYMBOL(avenrun);
-
-/*
- * calc_load - given tick count, update the avenrun load estimates.
- * This is called while holding a write_lock on xtime_lock.
- */
-static inline void calc_load(unsigned long ticks)
-{
- unsigned long active_tasks; /* fixed-point */
- static int count = LOAD_FREQ;
-
- count -= ticks;
- if (unlikely(count < 0)) {
- active_tasks = count_active_tasks();
- do {
- CALC_LOAD(avenrun[0], EXP_1, active_tasks);
- CALC_LOAD(avenrun[1], EXP_5, active_tasks);
- CALC_LOAD(avenrun[2], EXP_15, active_tasks);
- count += LOAD_FREQ;
- } while (count < 0);
- }
-}
-
-/*
* This function runs timers and the timer-tq in bottom half context.
*/
static void run_timer_softirq(struct softirq_action *h)
@@ -1187,16 +1146,6 @@ void run_local_timers(void)
}
/*
- * Called by the timer interrupt. xtime_lock must already be taken
- * by the timer IRQ!
- */
-static inline void update_times(unsigned long ticks)
-{
- update_wall_time();
- calc_load(ticks);
-}
-
-/*
* The 64-bit jiffies value is not atomic - you MUST NOT read it
* without sampling the sequence number in xtime_lock.
* jiffies is defined in the linker script...
@@ -1205,7 +1154,8 @@ static inline void update_times(unsigned long ticks)
void do_timer(unsigned long ticks)
{
jiffies_64 += ticks;
- update_times(ticks);
+ update_wall_time();
+ calc_global_load();
}
#ifdef __ARCH_WANT_SYS_ALARM
@@ -1406,37 +1356,17 @@ int do_sysinfo(struct sysinfo *info)
{
unsigned long mem_total, sav_total;
unsigned int mem_unit, bitcount;
- unsigned long seq;
+ struct timespec tp;
memset(info, 0, sizeof(struct sysinfo));
- do {
- struct timespec tp;
- seq = read_seqbegin(&xtime_lock);
-
- /*
- * This is annoying. The below is the same thing
- * posix_get_clock_monotonic() does, but it wants to
- * take the lock which we want to cover the loads stuff
- * too.
- */
-
- getnstimeofday(&tp);
- tp.tv_sec += wall_to_monotonic.tv_sec;
- tp.tv_nsec += wall_to_monotonic.tv_nsec;
- monotonic_to_bootbased(&tp);
- if (tp.tv_nsec - NSEC_PER_SEC >= 0) {
- tp.tv_nsec = tp.tv_nsec - NSEC_PER_SEC;
- tp.tv_sec++;
- }
- info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
+ ktime_get_ts(&tp);
+ monotonic_to_bootbased(&tp);
+ info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
- info->loads[0] = avenrun[0] << (SI_LOAD_SHIFT - FSHIFT);
- info->loads[1] = avenrun[1] << (SI_LOAD_SHIFT - FSHIFT);
- info->loads[2] = avenrun[2] << (SI_LOAD_SHIFT - FSHIFT);
+ get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
- info->procs = nr_threads;
- } while (read_seqretry(&xtime_lock, seq));
+ info->procs = nr_threads;
si_meminfo(info);
si_swapinfo(info);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1ce5dc6372b..cda81ec58d9 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2380,7 +2380,7 @@ static const char readme_msg[] =
"# echo print-parent > /debug/tracing/trace_options\n"
"# echo 1 > /debug/tracing/tracing_enabled\n"
"# cat /debug/tracing/trace > /tmp/trace.txt\n"
- "echo 0 > /debug/tracing/tracing_enabled\n"
+ "# echo 0 > /debug/tracing/tracing_enabled\n"
;
static ssize_t
@@ -3448,6 +3448,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
if (!ref)
break;
+ ref->ref = 1;
ref->buffer = info->tr->buffer;
ref->page = ring_buffer_alloc_read_page(ref->buffer);
if (!ref->page) {
diff --git a/kernel/wait.c b/kernel/wait.c
index 42a2dbc181c..ea7c3b4275c 100644
--- a/kernel/wait.c
+++ b/kernel/wait.c
@@ -154,7 +154,7 @@ void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait,
if (!list_empty(&wait->task_list))
list_del_init(&wait->task_list);
else if (waitqueue_active(q))
- __wake_up_common(q, mode, 1, 0, key);
+ __wake_up_locked_key(q, mode, key);
spin_unlock_irqrestore(&q->lock, flags);
}
EXPORT_SYMBOL(abort_exclusive_wait);