diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/tree.c | 22 | ||||
| -rw-r--r-- | kernel/rcu/tree.h | 14 | ||||
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 6 | ||||
| -rw-r--r-- | kernel/rcu/tree_trace.c | 2 | 
4 files changed, 28 insertions, 16 deletions
| diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 31e7021ced4d..3e2875b38eae 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -245,21 +245,21 @@ static int rcu_gp_in_progress(struct rcu_state *rsp)   */  void rcu_sched_qs(void)  { -	if (__this_cpu_read(rcu_sched_data.cpu_no_qs)) { +	if (__this_cpu_read(rcu_sched_data.cpu_no_qs.s)) {  		trace_rcu_grace_period(TPS("rcu_sched"),  				       __this_cpu_read(rcu_sched_data.gpnum),  				       TPS("cpuqs")); -		__this_cpu_write(rcu_sched_data.cpu_no_qs, false); +		__this_cpu_write(rcu_sched_data.cpu_no_qs.b.norm, false);  	}  }  void rcu_bh_qs(void)  { -	if (__this_cpu_read(rcu_bh_data.cpu_no_qs)) { +	if (__this_cpu_read(rcu_bh_data.cpu_no_qs.s)) {  		trace_rcu_grace_period(TPS("rcu_bh"),  				       __this_cpu_read(rcu_bh_data.gpnum),  				       TPS("cpuqs")); -		__this_cpu_write(rcu_bh_data.cpu_no_qs, false); +		__this_cpu_write(rcu_bh_data.cpu_no_qs.b.norm, false);  	}  } @@ -1744,7 +1744,7 @@ static bool __note_gp_changes(struct rcu_state *rsp, struct rcu_node *rnp,  		 */  		rdp->gpnum = rnp->gpnum;  		trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("cpustart")); -		rdp->cpu_no_qs = true; +		rdp->cpu_no_qs.b.norm = true;  		rdp->rcu_qs_ctr_snap = __this_cpu_read(rcu_qs_ctr);  		rdp->core_needs_qs = !!(rnp->qsmask & rdp->grpmask);  		zero_cpu_stall_ticks(rdp); @@ -2337,7 +2337,7 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp)  	rnp = rdp->mynode;  	raw_spin_lock_irqsave(&rnp->lock, flags);  	smp_mb__after_unlock_lock(); -	if ((rdp->cpu_no_qs && +	if ((rdp->cpu_no_qs.b.norm &&  	     rdp->rcu_qs_ctr_snap == __this_cpu_read(rcu_qs_ctr)) ||  	    rdp->gpnum != rnp->gpnum || rnp->completed == rnp->gpnum ||  	    rdp->gpwrap) { @@ -2348,7 +2348,7 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp)  		 * We will instead need a new quiescent state that lies  		 * within the current grace period.  		 */ -		rdp->cpu_no_qs = true;	/* need qs for new gp. */ +		rdp->cpu_no_qs.b.norm = true;	/* need qs for new gp. */  		rdp->rcu_qs_ctr_snap = __this_cpu_read(rcu_qs_ctr);  		raw_spin_unlock_irqrestore(&rnp->lock, flags);  		return; @@ -2395,7 +2395,7 @@ rcu_check_quiescent_state(struct rcu_state *rsp, struct rcu_data *rdp)  	 * Was there a quiescent state since the beginning of the grace  	 * period? If no, then exit and wait for the next call.  	 */ -	if (rdp->cpu_no_qs && +	if (rdp->cpu_no_qs.b.norm &&  	    rdp->rcu_qs_ctr_snap == __this_cpu_read(rcu_qs_ctr))  		return; @@ -3828,11 +3828,11 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)  	/* Is the RCU core waiting for a quiescent state from this CPU? */  	if (rcu_scheduler_fully_active && -	    rdp->core_needs_qs && rdp->cpu_no_qs && +	    rdp->core_needs_qs && rdp->cpu_no_qs.b.norm &&  	    rdp->rcu_qs_ctr_snap == __this_cpu_read(rcu_qs_ctr)) {  		rdp->n_rp_core_needs_qs++;  	} else if (rdp->core_needs_qs && -		   (!rdp->cpu_no_qs || +		   (!rdp->cpu_no_qs.b.norm ||  		    rdp->rcu_qs_ctr_snap != __this_cpu_read(rcu_qs_ctr))) {  		rdp->n_rp_report_qs++;  		return 1; @@ -4155,7 +4155,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)  	rdp->beenonline = true;	 /* We have now been online. */  	rdp->gpnum = rnp->completed; /* Make CPU later note any new GP. */  	rdp->completed = rnp->completed; -	rdp->cpu_no_qs = true; +	rdp->cpu_no_qs.b.norm = true;  	rdp->rcu_qs_ctr_snap = per_cpu(rcu_qs_ctr, cpu);  	rdp->core_needs_qs = false;  	trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("cpuonl")); diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index ded4ceebed76..3eee48bcf52b 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -286,6 +286,18 @@ struct rcu_node {  	for ((rnp) = (rsp)->level[rcu_num_lvls - 1]; \  	     (rnp) < &(rsp)->node[rcu_num_nodes]; (rnp)++) +/* + * Union to allow "aggregate OR" operation on the need for a quiescent + * state by the normal and expedited grace periods. + */ +union rcu_noqs { +	struct { +		u8 norm; +		u8 exp; +	} b; /* Bits. */ +	u16 s; /* Set of bits, aggregate OR here. */ +}; +  /* Index values for nxttail array in struct rcu_data. */  #define RCU_DONE_TAIL		0	/* Also RCU_WAIT head. */  #define RCU_WAIT_TAIL		1	/* Also RCU_NEXT_READY head. */ @@ -302,7 +314,7 @@ struct rcu_data {  					/*  is aware of having started. */  	unsigned long	rcu_qs_ctr_snap;/* Snapshot of rcu_qs_ctr to check */  					/*  for rcu_all_qs() invocations. */ -	bool		cpu_no_qs;	/* No QS yet for this CPU. */ +	union rcu_noqs	cpu_no_qs;	/* No QSes yet for this CPU. */  	bool		core_needs_qs;	/* Core waits for quiesc state. */  	bool		beenonline;	/* CPU online at least once. */  	bool		gpwrap;		/* Possible gpnum/completed wrap. */ diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 6977ff0dccb9..7880202f1e38 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -265,11 +265,11 @@ static void rcu_preempt_ctxt_queue(struct rcu_node *rnp, struct rcu_data *rdp,   */  static void rcu_preempt_qs(void)  { -	if (__this_cpu_read(rcu_data_p->cpu_no_qs)) { +	if (__this_cpu_read(rcu_data_p->cpu_no_qs.s)) {  		trace_rcu_grace_period(TPS("rcu_preempt"),  				       __this_cpu_read(rcu_data_p->gpnum),  				       TPS("cpuqs")); -		__this_cpu_write(rcu_data_p->cpu_no_qs, false); +		__this_cpu_write(rcu_data_p->cpu_no_qs.b.norm, false);  		barrier(); /* Coordinate with rcu_preempt_check_callbacks(). */  		current->rcu_read_unlock_special.b.need_qs = false;  	} @@ -620,7 +620,7 @@ static void rcu_preempt_check_callbacks(void)  	}  	if (t->rcu_read_lock_nesting > 0 &&  	    __this_cpu_read(rcu_data_p->core_needs_qs) && -	    __this_cpu_read(rcu_data_p->cpu_no_qs)) +	    __this_cpu_read(rcu_data_p->cpu_no_qs.b.norm))  		t->rcu_read_unlock_special.b.need_qs = true;  } diff --git a/kernel/rcu/tree_trace.c b/kernel/rcu/tree_trace.c index d373e57109b8..999c3672f990 100644 --- a/kernel/rcu/tree_trace.c +++ b/kernel/rcu/tree_trace.c @@ -121,7 +121,7 @@ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)  		   rdp->cpu,  		   cpu_is_offline(rdp->cpu) ? '!' : ' ',  		   ulong2long(rdp->completed), ulong2long(rdp->gpnum), -		   rdp->cpu_no_qs, +		   rdp->cpu_no_qs.b.norm,  		   rdp->rcu_qs_ctr_snap == per_cpu(rcu_qs_ctr, rdp->cpu),  		   rdp->core_needs_qs);  	seq_printf(m, " dt=%d/%llx/%d df=%lu", | 
