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Commit 1304afb2 authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Ingo Molnar
Browse files

rcu: Convert to raw_spinlocks 



The spinlocks in rcutree need to be real spinlocks in
preempt-rt. Convert them to raw_spinlocks.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-18-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 20133cfc

kernel/rcutree.c

+66 −66
Original line number Diff line number Diff line
@@ -66,11 +66,11 @@ static struct lock_class_key rcu_node_class[NUM_RCU_LVLS]; 
	.signaled = RCU_GP_IDLE, \

	.gpnum = -300, \

	.completed = -300, \

	.onofflock = __SPIN_LOCK_UNLOCKED(&name.onofflock), \

	.onofflock = __RAW_SPIN_LOCK_UNLOCKED(&name.onofflock), \

	.orphan_cbs_list = NULL, \

	.orphan_cbs_tail = &name.orphan_cbs_list, \

	.orphan_qlen = 0, \

	.fqslock = __SPIN_LOCK_UNLOCKED(&name.fqslock), \

	.fqslock = __RAW_SPIN_LOCK_UNLOCKED(&name.fqslock), \

	.n_force_qs = 0, \

	.n_force_qs_ngp = 0, \

}
@@ -457,10 +457,10 @@ static void print_other_cpu_stall(struct rcu_state *rsp) 


	/* Only let one CPU complain about others per time interval. */



	spin_lock_irqsave(&rnp->lock, flags);

	raw_spin_lock_irqsave(&rnp->lock, flags);

	delta = jiffies - rsp->jiffies_stall;

	if (delta < RCU_STALL_RAT_DELAY || !rcu_gp_in_progress(rsp)) {

		spin_unlock_irqrestore(&rnp->lock, flags);

		raw_spin_unlock_irqrestore(&rnp->lock, flags);

		return;

	}

	rsp->jiffies_stall = jiffies + RCU_SECONDS_TILL_STALL_RECHECK;
@@ -470,7 +470,7 @@ static void print_other_cpu_stall(struct rcu_state *rsp) 
	 * due to CPU offlining.

	 */

	rcu_print_task_stall(rnp);

	spin_unlock_irqrestore(&rnp->lock, flags);

	raw_spin_unlock_irqrestore(&rnp->lock, flags);



	/* OK, time to rat on our buddy... */
@@ -499,11 +499,11 @@ static void print_cpu_stall(struct rcu_state *rsp) 
			smp_processor_id(), jiffies - rsp->gp_start);

	trigger_all_cpu_backtrace();



	spin_lock_irqsave(&rnp->lock, flags);

	raw_spin_lock_irqsave(&rnp->lock, flags);

	if (ULONG_CMP_GE(jiffies, rsp->jiffies_stall))

		rsp->jiffies_stall =

			jiffies + RCU_SECONDS_TILL_STALL_RECHECK;

	spin_unlock_irqrestore(&rnp->lock, flags);

	raw_spin_unlock_irqrestore(&rnp->lock, flags);



	set_need_resched();  /* kick ourselves to get things going. */

}
@@ -563,12 +563,12 @@ static void note_new_gpnum(struct rcu_state *rsp, struct rcu_data *rdp) 
	local_irq_save(flags);

	rnp = rdp->mynode;

	if (rdp->gpnum == ACCESS_ONCE(rnp->gpnum) || /* outside lock. */

	    !spin_trylock(&rnp->lock)) { /* irqs already off, retry later. */

	    !raw_spin_trylock(&rnp->lock)) { /* irqs already off, so later. */

		local_irq_restore(flags);

		return;

	}

	__note_new_gpnum(rsp, rnp, rdp);

	spin_unlock_irqrestore(&rnp->lock, flags);

	raw_spin_unlock_irqrestore(&rnp->lock, flags);

}



/*
@@ -627,12 +627,12 @@ rcu_process_gp_end(struct rcu_state *rsp, struct rcu_data *rdp) 
	local_irq_save(flags);

	rnp = rdp->mynode;

	if (rdp->completed == ACCESS_ONCE(rnp->completed) || /* outside lock. */

	    !spin_trylock(&rnp->lock)) { /* irqs already off, retry later. */

	    !raw_spin_trylock(&rnp->lock)) { /* irqs already off, so later. */

		local_irq_restore(flags);

		return;

	}

	__rcu_process_gp_end(rsp, rnp, rdp);

	spin_unlock_irqrestore(&rnp->lock, flags);

	raw_spin_unlock_irqrestore(&rnp->lock, flags);

}



/*
@@ -681,10 +681,10 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) 
		if (cpu_needs_another_gp(rsp, rdp))

			rsp->fqs_need_gp = 1;

		if (rnp->completed == rsp->completed) {

			spin_unlock_irqrestore(&rnp->lock, flags);

			raw_spin_unlock_irqrestore(&rnp->lock, flags);

			return;

		}

		spin_unlock(&rnp->lock);	 /* irqs remain disabled. */

		raw_spin_unlock(&rnp->lock);	 /* irqs remain disabled. */



		/*

		 * Propagate new ->completed value to rcu_node structures
@@ -692,9 +692,9 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) 
		 * of the next grace period to process their callbacks.

		 */

		rcu_for_each_node_breadth_first(rsp, rnp) {

			spin_lock(&rnp->lock);	 /* irqs already disabled. */

			raw_spin_lock(&rnp->lock); /* irqs already disabled. */

			rnp->completed = rsp->completed;

			spin_unlock(&rnp->lock); /* irqs remain disabled. */

			raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */

		}

		local_irq_restore(flags);

		return;
@@ -715,15 +715,15 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) 
		rnp->completed = rsp->completed;

		rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state OK. */

		rcu_start_gp_per_cpu(rsp, rnp, rdp);

		spin_unlock_irqrestore(&rnp->lock, flags);

		raw_spin_unlock_irqrestore(&rnp->lock, flags);

		return;

	}



	spin_unlock(&rnp->lock);  /* leave irqs disabled. */

	raw_spin_unlock(&rnp->lock);  /* leave irqs disabled. */





	/* Exclude any concurrent CPU-hotplug operations. */

	spin_lock(&rsp->onofflock);  /* irqs already disabled. */

	raw_spin_lock(&rsp->onofflock);  /* irqs already disabled. */



	/*

	 * Set the quiescent-state-needed bits in all the rcu_node
@@ -743,21 +743,21 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) 
	 * irqs disabled.

	 */

	rcu_for_each_node_breadth_first(rsp, rnp) {

		spin_lock(&rnp->lock);		/* irqs already disabled. */

		raw_spin_lock(&rnp->lock);	/* irqs already disabled. */

		rcu_preempt_check_blocked_tasks(rnp);

		rnp->qsmask = rnp->qsmaskinit;

		rnp->gpnum = rsp->gpnum;

		rnp->completed = rsp->completed;

		if (rnp == rdp->mynode)

			rcu_start_gp_per_cpu(rsp, rnp, rdp);

		spin_unlock(&rnp->lock);	/* irqs remain disabled. */

		raw_spin_unlock(&rnp->lock);	/* irqs remain disabled. */

	}



	rnp = rcu_get_root(rsp);

	spin_lock(&rnp->lock);			/* irqs already disabled. */

	raw_spin_lock(&rnp->lock);		/* irqs already disabled. */

	rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state now OK. */

	spin_unlock(&rnp->lock);		/* irqs remain disabled. */

	spin_unlock_irqrestore(&rsp->onofflock, flags);

	raw_spin_unlock(&rnp->lock);		/* irqs remain disabled. */

	raw_spin_unlock_irqrestore(&rsp->onofflock, flags);

}



/*
@@ -796,14 +796,14 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp, 
		if (!(rnp->qsmask & mask)) {



			/* Our bit has already been cleared, so done. */

			spin_unlock_irqrestore(&rnp->lock, flags);

			raw_spin_unlock_irqrestore(&rnp->lock, flags);

			return;

		}

		rnp->qsmask &= ~mask;

		if (rnp->qsmask != 0 || rcu_preempted_readers(rnp)) {



			/* Other bits still set at this level, so done. */

			spin_unlock_irqrestore(&rnp->lock, flags);

			raw_spin_unlock_irqrestore(&rnp->lock, flags);

			return;

		}

		mask = rnp->grpmask;
@@ -813,10 +813,10 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp, 


			break;

		}

		spin_unlock_irqrestore(&rnp->lock, flags);

		raw_spin_unlock_irqrestore(&rnp->lock, flags);

		rnp_c = rnp;

		rnp = rnp->parent;

		spin_lock_irqsave(&rnp->lock, flags);

		raw_spin_lock_irqsave(&rnp->lock, flags);

		WARN_ON_ONCE(rnp_c->qsmask);

	}
@@ -845,7 +845,7 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long las 
	struct rcu_node *rnp;



	rnp = rdp->mynode;

	spin_lock_irqsave(&rnp->lock, flags);

	raw_spin_lock_irqsave(&rnp->lock, flags);

	if (lastcomp != rnp->completed) {



		/*
@@ -857,12 +857,12 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long las 
		 * race occurred.

		 */

		rdp->passed_quiesc = 0;	/* try again later! */

		spin_unlock_irqrestore(&rnp->lock, flags);

		raw_spin_unlock_irqrestore(&rnp->lock, flags);

		return;

	}

	mask = rdp->grpmask;

	if ((rnp->qsmask & mask) == 0) {

		spin_unlock_irqrestore(&rnp->lock, flags);

		raw_spin_unlock_irqrestore(&rnp->lock, flags);

	} else {

		rdp->qs_pending = 0;
@@ -926,7 +926,7 @@ static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp) 


	if (rdp->nxtlist == NULL)

		return;  /* irqs disabled, so comparison is stable. */

	spin_lock(&rsp->onofflock);  /* irqs already disabled. */

	raw_spin_lock(&rsp->onofflock);  /* irqs already disabled. */

	*rsp->orphan_cbs_tail = rdp->nxtlist;

	rsp->orphan_cbs_tail = rdp->nxttail[RCU_NEXT_TAIL];

	rdp->nxtlist = NULL;
@@ -934,7 +934,7 @@ static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp) 
		rdp->nxttail[i] = &rdp->nxtlist;

	rsp->orphan_qlen += rdp->qlen;

	rdp->qlen = 0;

	spin_unlock(&rsp->onofflock);  /* irqs remain disabled. */

	raw_spin_unlock(&rsp->onofflock);  /* irqs remain disabled. */

}



/*
@@ -945,10 +945,10 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp) 
	unsigned long flags;

	struct rcu_data *rdp;



	spin_lock_irqsave(&rsp->onofflock, flags);

	raw_spin_lock_irqsave(&rsp->onofflock, flags);

	rdp = rsp->rda[smp_processor_id()];

	if (rsp->orphan_cbs_list == NULL) {

		spin_unlock_irqrestore(&rsp->onofflock, flags);

		raw_spin_unlock_irqrestore(&rsp->onofflock, flags);

		return;

	}

	*rdp->nxttail[RCU_NEXT_TAIL] = rsp->orphan_cbs_list;
@@ -957,7 +957,7 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp) 
	rsp->orphan_cbs_list = NULL;

	rsp->orphan_cbs_tail = &rsp->orphan_cbs_list;

	rsp->orphan_qlen = 0;

	spin_unlock_irqrestore(&rsp->onofflock, flags);

	raw_spin_unlock_irqrestore(&rsp->onofflock, flags);

}



/*
@@ -973,23 +973,23 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) 
	struct rcu_node *rnp;



	/* Exclude any attempts to start a new grace period. */

	spin_lock_irqsave(&rsp->onofflock, flags);

	raw_spin_lock_irqsave(&rsp->onofflock, flags);



	/* Remove the outgoing CPU from the masks in the rcu_node hierarchy. */

	rnp = rdp->mynode;	/* this is the outgoing CPU's rnp. */

	mask = rdp->grpmask;	/* rnp->grplo is constant. */

	do {

		spin_lock(&rnp->lock);		/* irqs already disabled. */

		raw_spin_lock(&rnp->lock);	/* irqs already disabled. */

		rnp->qsmaskinit &= ~mask;

		if (rnp->qsmaskinit != 0) {

			if (rnp != rdp->mynode)

				spin_unlock(&rnp->lock); /* irqs remain disabled. */

				raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */

			break;

		}

		if (rnp == rdp->mynode)

			need_report = rcu_preempt_offline_tasks(rsp, rnp, rdp);

		else

			spin_unlock(&rnp->lock); /* irqs remain disabled. */

			raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */

		mask = rnp->grpmask;

		rnp = rnp->parent;

	} while (rnp != NULL);
@@ -1000,12 +1000,12 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) 
	 * because invoking rcu_report_unblock_qs_rnp() with ->onofflock

	 * held leads to deadlock.

	 */

	spin_unlock(&rsp->onofflock); /* irqs remain disabled. */

	raw_spin_unlock(&rsp->onofflock); /* irqs remain disabled. */

	rnp = rdp->mynode;

	if (need_report & RCU_OFL_TASKS_NORM_GP)

		rcu_report_unblock_qs_rnp(rnp, flags);

	else

		spin_unlock_irqrestore(&rnp->lock, flags);

		raw_spin_unlock_irqrestore(&rnp->lock, flags);

	if (need_report & RCU_OFL_TASKS_EXP_GP)

		rcu_report_exp_rnp(rsp, rnp);
@@ -1176,13 +1176,13 @@ static void force_qs_rnp(struct rcu_state *rsp, int (*f)(struct rcu_data *)) 


	rcu_for_each_leaf_node(rsp, rnp) {

		mask = 0;

		spin_lock_irqsave(&rnp->lock, flags);

		raw_spin_lock_irqsave(&rnp->lock, flags);

		if (!rcu_gp_in_progress(rsp)) {

			spin_unlock_irqrestore(&rnp->lock, flags);

			raw_spin_unlock_irqrestore(&rnp->lock, flags);

			return;

		}

		if (rnp->qsmask == 0) {

			spin_unlock_irqrestore(&rnp->lock, flags);

			raw_spin_unlock_irqrestore(&rnp->lock, flags);

			continue;

		}

		cpu = rnp->grplo;
@@ -1197,7 +1197,7 @@ static void force_qs_rnp(struct rcu_state *rsp, int (*f)(struct rcu_data *)) 
			rcu_report_qs_rnp(mask, rsp, rnp, flags);

			continue;

		}

		spin_unlock_irqrestore(&rnp->lock, flags);

		raw_spin_unlock_irqrestore(&rnp->lock, flags);

	}

}
@@ -1212,18 +1212,18 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed) 


	if (!rcu_gp_in_progress(rsp))

		return;  /* No grace period in progress, nothing to force. */

	if (!spin_trylock_irqsave(&rsp->fqslock, flags)) {

	if (!raw_spin_trylock_irqsave(&rsp->fqslock, flags)) {

		rsp->n_force_qs_lh++; /* Inexact, can lose counts.  Tough! */

		return;	/* Someone else is already on the job. */

	}

	if (relaxed && ULONG_CMP_GE(rsp->jiffies_force_qs, jiffies))

		goto unlock_fqs_ret; /* no emergency and done recently. */

	rsp->n_force_qs++;

	spin_lock(&rnp->lock);  /* irqs already disabled */

	raw_spin_lock(&rnp->lock);  /* irqs already disabled */

	rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS;

	if(!rcu_gp_in_progress(rsp)) {

		rsp->n_force_qs_ngp++;

		spin_unlock(&rnp->lock);  /* irqs remain disabled */

		raw_spin_unlock(&rnp->lock);  /* irqs remain disabled */

		goto unlock_fqs_ret;  /* no GP in progress, time updated. */

	}

	rsp->fqs_active = 1;
@@ -1235,13 +1235,13 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed) 


	case RCU_SAVE_DYNTICK:



		spin_unlock(&rnp->lock);  /* irqs remain disabled */

		raw_spin_unlock(&rnp->lock);  /* irqs remain disabled */

		if (RCU_SIGNAL_INIT != RCU_SAVE_DYNTICK)

			break; /* So gcc recognizes the dead code. */



		/* Record dyntick-idle state. */

		force_qs_rnp(rsp, dyntick_save_progress_counter);

		spin_lock(&rnp->lock);  /* irqs already disabled */

		raw_spin_lock(&rnp->lock);  /* irqs already disabled */

		if (rcu_gp_in_progress(rsp))

			rsp->signaled = RCU_FORCE_QS;

		break;
@@ -1249,24 +1249,24 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed) 
	case RCU_FORCE_QS:



		/* Check dyntick-idle state, send IPI to laggarts. */

		spin_unlock(&rnp->lock);  /* irqs remain disabled */

		raw_spin_unlock(&rnp->lock);  /* irqs remain disabled */

		force_qs_rnp(rsp, rcu_implicit_dynticks_qs);



		/* Leave state in case more forcing is required. */



		spin_lock(&rnp->lock);  /* irqs already disabled */

		raw_spin_lock(&rnp->lock);  /* irqs already disabled */

		break;

	}

	rsp->fqs_active = 0;

	if (rsp->fqs_need_gp) {

		spin_unlock(&rsp->fqslock); /* irqs remain disabled */

		raw_spin_unlock(&rsp->fqslock); /* irqs remain disabled */

		rsp->fqs_need_gp = 0;

		rcu_start_gp(rsp, flags); /* releases rnp->lock */

		return;

	}

	spin_unlock(&rnp->lock);  /* irqs remain disabled */

	raw_spin_unlock(&rnp->lock);  /* irqs remain disabled */

unlock_fqs_ret:

	spin_unlock_irqrestore(&rsp->fqslock, flags);

	raw_spin_unlock_irqrestore(&rsp->fqslock, flags);

}



#else /* #ifdef CONFIG_SMP */
@@ -1308,7 +1308,7 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp) 


	/* Does this CPU require a not-yet-started grace period? */

	if (cpu_needs_another_gp(rsp, rdp)) {

		spin_lock_irqsave(&rcu_get_root(rsp)->lock, flags);

		raw_spin_lock_irqsave(&rcu_get_root(rsp)->lock, flags);

		rcu_start_gp(rsp, flags);  /* releases above lock */

	}
@@ -1373,7 +1373,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu), 
		unsigned long nestflag;

		struct rcu_node *rnp_root = rcu_get_root(rsp);



		spin_lock_irqsave(&rnp_root->lock, nestflag);

		raw_spin_lock_irqsave(&rnp_root->lock, nestflag);

		rcu_start_gp(rsp, nestflag);  /* releases rnp_root->lock. */

	}
@@ -1662,7 +1662,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp) 
	struct rcu_node *rnp = rcu_get_root(rsp);



	/* Set up local state, ensuring consistent view of global state. */

	spin_lock_irqsave(&rnp->lock, flags);

	raw_spin_lock_irqsave(&rnp->lock, flags);

	rdp->grpmask = 1UL << (cpu - rdp->mynode->grplo);

	rdp->nxtlist = NULL;

	for (i = 0; i < RCU_NEXT_SIZE; i++)
@@ -1672,7 +1672,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp) 
	rdp->dynticks = &per_cpu(rcu_dynticks, cpu);

#endif /* #ifdef CONFIG_NO_HZ */

	rdp->cpu = cpu;

	spin_unlock_irqrestore(&rnp->lock, flags);

	raw_spin_unlock_irqrestore(&rnp->lock, flags);

}



/*
@@ -1690,7 +1690,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable) 
	struct rcu_node *rnp = rcu_get_root(rsp);



	/* Set up local state, ensuring consistent view of global state. */

	spin_lock_irqsave(&rnp->lock, flags);

	raw_spin_lock_irqsave(&rnp->lock, flags);

	rdp->passed_quiesc = 0;  /* We could be racing with new GP, */

	rdp->qs_pending = 1;	 /*  so set up to respond to current GP. */

	rdp->beenonline = 1;	 /* We have now been online. */
@@ -1698,7 +1698,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable) 
	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. */

	raw_spin_unlock(&rnp->lock);		/* irqs remain disabled. */



	/*

	 * A new grace period might start here.  If so, we won't be part
@@ -1706,14 +1706,14 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable) 
	 */



	/* Exclude any attempts to start a new GP on large systems. */

	spin_lock(&rsp->onofflock);		/* irqs already disabled. */

	raw_spin_lock(&rsp->onofflock);		/* irqs already disabled. */



	/* Add CPU to rcu_node bitmasks. */

	rnp = rdp->mynode;

	mask = rdp->grpmask;

	do {

		/* Exclude any attempts to start a new GP on small systems. */

		spin_lock(&rnp->lock);	/* irqs already disabled. */

		raw_spin_lock(&rnp->lock);	/* irqs already disabled. */

		rnp->qsmaskinit |= mask;

		mask = rnp->grpmask;

		if (rnp == rdp->mynode) {
@@ -1721,11 +1721,11 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable) 
			rdp->completed = rnp->completed;

			rdp->passed_quiesc_completed = rnp->completed - 1;

		}

		spin_unlock(&rnp->lock); /* irqs already disabled. */

		raw_spin_unlock(&rnp->lock); /* irqs already disabled. */

		rnp = rnp->parent;

	} while (rnp != NULL && !(rnp->qsmaskinit & mask));



	spin_unlock_irqrestore(&rsp->onofflock, flags);

	raw_spin_unlock_irqrestore(&rsp->onofflock, flags);

}



static void __cpuinit rcu_online_cpu(int cpu)
@@ -1832,7 +1832,7 @@ static void __init rcu_init_one(struct rcu_state *rsp) 
		cpustride *= rsp->levelspread[i];

		rnp = rsp->level[i];

		for (j = 0; j < rsp->levelcnt[i]; j++, rnp++) {

			spin_lock_init(&rnp->lock);

			raw_spin_lock_init(&rnp->lock);

			lockdep_set_class_and_name(&rnp->lock,

						   &rcu_node_class[i], buf[i]);

			rnp->gpnum = 0;

kernel/rcutree.h

+3 −3
Original line number Diff line number Diff line
@@ -90,7 +90,7 @@ struct rcu_dynticks { 
 * Definition for node within the RCU grace-period-detection hierarchy.

 */

struct rcu_node {

	spinlock_t lock;	/* Root rcu_node's lock protects some */

	raw_spinlock_t lock;	/* Root rcu_node's lock protects some */

				/*  rcu_state fields as well as following. */

	unsigned long gpnum;	/* Current grace period for this node. */

				/*  This will either be equal to or one */
@@ -291,7 +291,7 @@ struct rcu_state { 


	/* End of fields guarded by root rcu_node's lock. */



	spinlock_t onofflock;			/* exclude on/offline and */

	raw_spinlock_t onofflock;		/* exclude on/offline and */

						/*  starting new GP.  Also */

						/*  protects the following */

						/*  orphan_cbs fields. */
@@ -301,7 +301,7 @@ struct rcu_state { 
						/*  going offline. */

	struct rcu_head **orphan_cbs_tail;	/* And tail pointer. */

	long orphan_qlen;			/* Number of orphaned cbs. */

	spinlock_t fqslock;			/* Only one task forcing */

	raw_spinlock_t fqslock;			/* Only one task forcing */

						/*  quiescent states. */

	unsigned long jiffies_force_qs;		/* Time at which to invoke */

						/*  force_quiescent_state(). */

kernel/rcutree_plugin.h

+23 −23
Original line number Diff line number Diff line
@@ -111,7 +111,7 @@ static void rcu_preempt_note_context_switch(int cpu) 
		/* Possibly blocking in an RCU read-side critical section. */

		rdp = rcu_preempt_state.rda[cpu];

		rnp = rdp->mynode;

		spin_lock_irqsave(&rnp->lock, flags);

		raw_spin_lock_irqsave(&rnp->lock, flags);

		t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BLOCKED;

		t->rcu_blocked_node = rnp;
@@ -132,7 +132,7 @@ static void rcu_preempt_note_context_switch(int cpu) 
		WARN_ON_ONCE(!list_empty(&t->rcu_node_entry));

		phase = (rnp->gpnum + !(rnp->qsmask & rdp->grpmask)) & 0x1;

		list_add(&t->rcu_node_entry, &rnp->blocked_tasks[phase]);

		spin_unlock_irqrestore(&rnp->lock, flags);

		raw_spin_unlock_irqrestore(&rnp->lock, flags);

	}



	/*
@@ -189,7 +189,7 @@ static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags) 
	struct rcu_node *rnp_p;



	if (rnp->qsmask != 0 || rcu_preempted_readers(rnp)) {

		spin_unlock_irqrestore(&rnp->lock, flags);

		raw_spin_unlock_irqrestore(&rnp->lock, flags);

		return;  /* Still need more quiescent states! */

	}
@@ -206,8 +206,8 @@ static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags) 


	/* Report up the rest of the hierarchy. */

	mask = rnp->grpmask;

	spin_unlock(&rnp->lock);	/* irqs remain disabled. */

	spin_lock(&rnp_p->lock);	/* irqs already disabled. */

	raw_spin_unlock(&rnp->lock);	/* irqs remain disabled. */

	raw_spin_lock(&rnp_p->lock);	/* irqs already disabled. */

	rcu_report_qs_rnp(mask, &rcu_preempt_state, rnp_p, flags);

}
@@ -257,10 +257,10 @@ static void rcu_read_unlock_special(struct task_struct *t) 
		 */

		for (;;) {

			rnp = t->rcu_blocked_node;

			spin_lock(&rnp->lock);  /* irqs already disabled. */

			raw_spin_lock(&rnp->lock);  /* irqs already disabled. */

			if (rnp == t->rcu_blocked_node)

				break;

			spin_unlock(&rnp->lock);  /* irqs remain disabled. */

			raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */

		}

		empty = !rcu_preempted_readers(rnp);

		empty_exp = !rcu_preempted_readers_exp(rnp);
@@ -274,7 +274,7 @@ static void rcu_read_unlock_special(struct task_struct *t) 
		 * Note that rcu_report_unblock_qs_rnp() releases rnp->lock.

		 */

		if (empty)

			spin_unlock_irqrestore(&rnp->lock, flags);

			raw_spin_unlock_irqrestore(&rnp->lock, flags);

		else

			rcu_report_unblock_qs_rnp(rnp, flags);
@@ -324,12 +324,12 @@ static void rcu_print_task_stall(struct rcu_node *rnp) 
	struct task_struct *t;



	if (rcu_preempted_readers(rnp)) {

		spin_lock_irqsave(&rnp->lock, flags);

		raw_spin_lock_irqsave(&rnp->lock, flags);

		phase = rnp->gpnum & 0x1;

		lp = &rnp->blocked_tasks[phase];

		list_for_each_entry(t, lp, rcu_node_entry)

			printk(" P%d", t->pid);

		spin_unlock_irqrestore(&rnp->lock, flags);

		raw_spin_unlock_irqrestore(&rnp->lock, flags);

	}

}
@@ -400,11 +400,11 @@ static int rcu_preempt_offline_tasks(struct rcu_state *rsp, 
		lp_root = &rnp_root->blocked_tasks[i];

		while (!list_empty(lp)) {

			tp = list_entry(lp->next, typeof(*tp), rcu_node_entry);

			spin_lock(&rnp_root->lock); /* irqs already disabled */

			raw_spin_lock(&rnp_root->lock); /* irqs already disabled */

			list_del(&tp->rcu_node_entry);

			tp->rcu_blocked_node = rnp_root;

			list_add(&tp->rcu_node_entry, lp_root);

			spin_unlock(&rnp_root->lock); /* irqs remain disabled */

			raw_spin_unlock(&rnp_root->lock); /* irqs remain disabled */

		}

	}

	return retval;
@@ -528,7 +528,7 @@ static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp) 
	unsigned long flags;

	unsigned long mask;



	spin_lock_irqsave(&rnp->lock, flags);

	raw_spin_lock_irqsave(&rnp->lock, flags);

	for (;;) {

		if (!sync_rcu_preempt_exp_done(rnp))

			break;
@@ -537,12 +537,12 @@ static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp) 
			break;

		}

		mask = rnp->grpmask;

		spin_unlock(&rnp->lock); /* irqs remain disabled */

		raw_spin_unlock(&rnp->lock); /* irqs remain disabled */

		rnp = rnp->parent;

		spin_lock(&rnp->lock); /* irqs already disabled */

		raw_spin_lock(&rnp->lock); /* irqs already disabled */

		rnp->expmask &= ~mask;

	}

	spin_unlock_irqrestore(&rnp->lock, flags);

	raw_spin_unlock_irqrestore(&rnp->lock, flags);

}



/*
@@ -557,11 +557,11 @@ sync_rcu_preempt_exp_init(struct rcu_state *rsp, struct rcu_node *rnp) 
{

	int must_wait;



	spin_lock(&rnp->lock); /* irqs already disabled */

	raw_spin_lock(&rnp->lock); /* irqs already disabled */

	list_splice_init(&rnp->blocked_tasks[0], &rnp->blocked_tasks[2]);

	list_splice_init(&rnp->blocked_tasks[1], &rnp->blocked_tasks[3]);

	must_wait = rcu_preempted_readers_exp(rnp);

	spin_unlock(&rnp->lock); /* irqs remain disabled */

	raw_spin_unlock(&rnp->lock); /* irqs remain disabled */

	if (!must_wait)

		rcu_report_exp_rnp(rsp, rnp);

}
@@ -606,13 +606,13 @@ void synchronize_rcu_expedited(void) 
	/* force all RCU readers onto blocked_tasks[]. */

	synchronize_sched_expedited();



	spin_lock_irqsave(&rsp->onofflock, flags);

	raw_spin_lock_irqsave(&rsp->onofflock, flags);



	/* Initialize ->expmask for all non-leaf rcu_node structures. */

	rcu_for_each_nonleaf_node_breadth_first(rsp, rnp) {

		spin_lock(&rnp->lock); /* irqs already disabled. */

		raw_spin_lock(&rnp->lock); /* irqs already disabled. */

		rnp->expmask = rnp->qsmaskinit;

		spin_unlock(&rnp->lock); /* irqs remain disabled. */

		raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */

	}



	/* Snapshot current state of ->blocked_tasks[] lists. */
@@ -621,7 +621,7 @@ void synchronize_rcu_expedited(void) 
	if (NUM_RCU_NODES > 1)

		sync_rcu_preempt_exp_init(rsp, rcu_get_root(rsp));



	spin_unlock_irqrestore(&rsp->onofflock, flags);

	raw_spin_unlock_irqrestore(&rsp->onofflock, flags);



	/* Wait for snapshotted ->blocked_tasks[] lists to drain. */

	rnp = rcu_get_root(rsp);
@@ -756,7 +756,7 @@ static int rcu_preempted_readers(struct rcu_node *rnp) 
/* Because preemptible RCU does not exist, no quieting of tasks. */

static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags)

{

	spin_unlock_irqrestore(&rnp->lock, flags);

	raw_spin_unlock_irqrestore(&rnp->lock, flags);

}



#endif /* #ifdef CONFIG_HOTPLUG_CPU */