Merge branch 'core-fixes-for-linus' of... (fefcfd43) · Commits · 戴 / test

include/linux/rcutree.h

+1 −5

Original line number	Diff line number	Diff line
		@@ -76,11 +76,7 @@ static inline void __rcu_read_unlock_bh(void)

		extern void call_rcu_sched(struct rcu_head *head,
		void (func)(struct rcu_head rcu));

		static inline void synchronize_rcu_expedited(void)
		{
		synchronize_sched_expedited();
		}
		extern void synchronize_rcu_expedited(void);

		static inline void synchronize_rcu_bh_expedited(void)
		{

kernel/futex.c

+19 −5

Original line number	Diff line number	Diff line
		@@ -150,7 +150,8 @@ static struct futex_hash_bucket hash_futex(union futex_key key)
		*/
		static inline int match_futex(union futex_key key1, union futex_key key2)
		{
		return (key1->both.word == key2->both.word
		return (key1 && key2
		&& key1->both.word == key2->both.word
		&& key1->both.ptr == key2->both.ptr
		&& key1->both.offset == key2->both.offset);
		}
		@@ -1028,7 +1029,6 @@ static inline
		void requeue_pi_wake_futex(struct futex_q q, union futex_key key,
		struct futex_hash_bucket *hb)
		{
		drop_futex_key_refs(&q->key);
		get_futex_key_refs(key);
		q->key = *key;

		@@ -1226,6 +1226,7 @@ retry_private:
		*/
		if (ret == 1) {
		WARN_ON(pi_state);
		drop_count++;
		task_count++;
		ret = get_futex_value_locked(&curval2, uaddr2);
		if (!ret)
		@@ -1304,6 +1305,7 @@ retry_private:
		if (ret == 1) {
		/* We got the lock. */
		requeue_pi_wake_futex(this, &key2, hb2);
		drop_count++;
		continue;
		} else if (ret) {
		/* -EDEADLK */
		@@ -1791,6 +1793,7 @@ static int futex_wait(u32 __user *uaddr, int fshared,
		current->timer_slack_ns);
		}

		retry:
		/* Prepare to wait on uaddr. */
		ret = futex_wait_setup(uaddr, val, fshared, &q, &hb);
		if (ret)
		@@ -1808,9 +1811,14 @@ static int futex_wait(u32 __user *uaddr, int fshared,
		goto out_put_key;

		/*
		* We expect signal_pending(current), but another thread may
		* have handled it for us already.
		* We expect signal_pending(current), but we might be the
		* victim of a spurious wakeup as well.
		*/
		if (!signal_pending(current)) {
		put_futex_key(fshared, &q.key);
		goto retry;
		}

		ret = -ERESTARTSYS;
		if (!abs_time)
		goto out_put_key;
		@@ -2118,9 +2126,11 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
		*/
		plist_del(&q->list, &q->list.plist);

		/* Handle spurious wakeups gracefully */
		ret = -EAGAIN;
		if (timeout && !timeout->task)
		ret = -ETIMEDOUT;
		else
		else if (signal_pending(current))
		ret = -ERESTARTNOINTR;
		}
		return ret;
		@@ -2198,6 +2208,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared,
		debug_rt_mutex_init_waiter(&rt_waiter);
		rt_waiter.task = NULL;

		retry:
		key2 = FUTEX_KEY_INIT;
		ret = get_futex_key(uaddr2, fshared, &key2, VERIFY_WRITE);
		if (unlikely(ret != 0))
		@@ -2292,6 +2303,9 @@ out_put_keys:
		out_key2:
		put_futex_key(fshared, &key2);

		/* Spurious wakeup ? */
		if (ret == -EAGAIN)
		goto retry;
		out:
		if (to) {
		hrtimer_cancel(&to->timer);

kernel/rcutree.c

+38 −6

Original line number	Diff line number	Diff line
		@@ -913,7 +913,20 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
		spin_unlock(&rnp->lock); /* irqs remain disabled. */
		break;
		}
		rcu_preempt_offline_tasks(rsp, rnp, rdp);

		/*
		* If there was a task blocking the current grace period,
		* and if all CPUs have checked in, we need to propagate
		* the quiescent state up the rcu_node hierarchy. But that
		* is inconvenient at the moment due to deadlock issues if
		* this should end the current grace period. So set the
		* offlined CPU's bit in ->qsmask in order to force the
		* next force_quiescent_state() invocation to clean up this
		* mess in a deadlock-free manner.
		*/
		if (rcu_preempt_offline_tasks(rsp, rnp, rdp) && !rnp->qsmask)
		rnp->qsmask \|= mask;

		mask = rnp->grpmask;
		spin_unlock(&rnp->lock); /* irqs remain disabled. */
		rnp = rnp->parent;
		@@ -958,7 +971,7 @@ static void rcu_offline_cpu(int cpu)
		* Invoke any RCU callbacks that have made it to the end of their grace
		* period. Thottle as specified by rdp->blimit.
		*/
		static void rcu_do_batch(struct rcu_data *rdp)
		static void rcu_do_batch(struct rcu_state rsp, struct rcu_data rdp)
		{
		unsigned long flags;
		struct rcu_head next, list, **tail;
		@@ -1011,6 +1024,13 @@ static void rcu_do_batch(struct rcu_data *rdp)
		if (rdp->blimit == LONG_MAX && rdp->qlen <= qlowmark)
		rdp->blimit = blimit;

		/* Reset ->qlen_last_fqs_check trigger if enough CBs have drained. */
		if (rdp->qlen == 0 && rdp->qlen_last_fqs_check != 0) {
		rdp->qlen_last_fqs_check = 0;
		rdp->n_force_qs_snap = rsp->n_force_qs;
		} else if (rdp->qlen < rdp->qlen_last_fqs_check - qhimark)
		rdp->qlen_last_fqs_check = rdp->qlen;

		local_irq_restore(flags);

		/* Re-raise the RCU softirq if there are callbacks remaining. */
		@@ -1224,7 +1244,7 @@ __rcu_process_callbacks(struct rcu_state rsp, struct rcu_data rdp)
		}

		/* If there are callbacks ready, invoke them. */
		rcu_do_batch(rdp);
		rcu_do_batch(rsp, rdp);
		}

		/*
		@@ -1288,10 +1308,20 @@ __call_rcu(struct rcu_head head, void (func)(struct rcu_head *rcu),
		rcu_start_gp(rsp, nestflag); /* releases rnp_root->lock. */
		}

		/* Force the grace period if too many callbacks or too long waiting. */
		if (unlikely(++rdp->qlen > qhimark)) {
		/*
		* Force the grace period if too many callbacks or too long waiting.
		* Enforce hysteresis, and don't invoke force_quiescent_state()
		* if some other CPU has recently done so. Also, don't bother
		* invoking force_quiescent_state() if the newly enqueued callback
		* is the only one waiting for a grace period to complete.
		*/
		if (unlikely(++rdp->qlen > rdp->qlen_last_fqs_check + qhimark)) {
		rdp->blimit = LONG_MAX;
		if (rsp->n_force_qs == rdp->n_force_qs_snap &&
		*rdp->nxttail[RCU_DONE_TAIL] != head)
		force_quiescent_state(rsp, 0);
		rdp->n_force_qs_snap = rsp->n_force_qs;
		rdp->qlen_last_fqs_check = rdp->qlen;
		} else if ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0)
		force_quiescent_state(rsp, 1);
		local_irq_restore(flags);
		@@ -1523,6 +1553,8 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable)
		rdp->beenonline = 1; /* We have now been online. */
		rdp->preemptable = preemptable;
		rdp->passed_quiesc_completed = lastcomp - 1;
		rdp->qlen_last_fqs_check = 0;
		rdp->n_force_qs_snap = rsp->n_force_qs;
		rdp->blimit = blimit;
		spin_unlock(&rnp->lock); /* irqs remain disabled. */

kernel/rcutree.h

+7 −3

Original line number	Diff line number	Diff line
		@@ -167,6 +167,10 @@ struct rcu_data {
		struct rcu_head *nxtlist;
		struct rcu_head **nxttail[RCU_NEXT_SIZE];
		long qlen; /* # of queued callbacks */
		long qlen_last_fqs_check;
		/* qlen at last check for QS forcing */
		unsigned long n_force_qs_snap;
		/* did other CPU force QS recently? */
		long blimit; /* Upper limit on a processed batch */

		#ifdef CONFIG_NO_HZ
		@@ -302,7 +306,7 @@ static void rcu_print_task_stall(struct rcu_node *rnp);
		#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
		static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp);
		#ifdef CONFIG_HOTPLUG_CPU
		static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
		static int rcu_preempt_offline_tasks(struct rcu_state *rsp,
		struct rcu_node *rnp,
		struct rcu_data *rdp);
		static void rcu_preempt_offline_cpu(int cpu);

kernel/rcutree_plugin.h

+38 −8

Original line number	Diff line number	Diff line
		@@ -304,21 +304,25 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp)
		* parent is to remove the need for rcu_read_unlock_special() to
		* make more than two attempts to acquire the target rcu_node's lock.
		*
		* Returns 1 if there was previously a task blocking the current grace
		* period on the specified rcu_node structure.
		*
		* The caller must hold rnp->lock with irqs disabled.
		*/
		static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
		static int rcu_preempt_offline_tasks(struct rcu_state *rsp,
		struct rcu_node *rnp,
		struct rcu_data *rdp)
		{
		int i;
		struct list_head *lp;
		struct list_head *lp_root;
		int retval = rcu_preempted_readers(rnp);
		struct rcu_node *rnp_root = rcu_get_root(rsp);
		struct task_struct *tp;

		if (rnp == rnp_root) {
		WARN_ONCE(1, "Last CPU thought to be offlined?");
		return; /* Shouldn't happen: at least one CPU online. */
		return 0; /* Shouldn't happen: at least one CPU online. */
		}
		WARN_ON_ONCE(rnp != rdp->mynode &&
		(!list_empty(&rnp->blocked_tasks[0]) \|\|
		@@ -342,6 +346,8 @@ static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
		spin_unlock(&rnp_root->lock); /* irqs remain disabled */
		}
		}

		return retval;
		}

		/*
		@@ -392,6 +398,17 @@ void call_rcu(struct rcu_head head, void (func)(struct rcu_head *rcu))
		}
		EXPORT_SYMBOL_GPL(call_rcu);

		/*
		* Wait for an rcu-preempt grace period. We are supposed to expedite the
		* grace period, but this is the crude slow compatability hack, so just
		* invoke synchronize_rcu().
		*/
		void synchronize_rcu_expedited(void)
		{
		synchronize_rcu();
		}
		EXPORT_SYMBOL_GPL(synchronize_rcu_expedited);

		/*
		* Check to see if there is any immediate preemptable-RCU-related work
		* to be done.
		@@ -521,12 +538,15 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp)

		/*
		* Because preemptable RCU does not exist, it never needs to migrate
		* tasks that were blocked within RCU read-side critical sections.
		* tasks that were blocked within RCU read-side critical sections, and
		* such non-existent tasks cannot possibly have been blocking the current
		* grace period.
		*/
		static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
		static int rcu_preempt_offline_tasks(struct rcu_state *rsp,
		struct rcu_node *rnp,
		struct rcu_data *rdp)
		{
		return 0;
		}

		/*
		@@ -564,6 +584,16 @@ void call_rcu(struct rcu_head head, void (func)(struct rcu_head *rcu))
		}
		EXPORT_SYMBOL_GPL(call_rcu);

		/*
		* Wait for an rcu-preempt grace period, but make it happen quickly.
		* But because preemptable RCU does not exist, map to rcu-sched.
		*/
		void synchronize_rcu_expedited(void)
		{
		synchronize_sched_expedited();
		}
		EXPORT_SYMBOL_GPL(synchronize_rcu_expedited);

		/*
		* Because preemptable RCU does not exist, it never has any work to do.
		*/

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