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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-08-06 15:16:57 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-09-20 21:16:21 -0700
commit5b74c458906fc4a62f932ee8bb801d29baf15fec (patch)
treeb5fde68e681dc589e40347ee939a1433d70bd77a /kernel/rcu/tree.c
parent0d43eb34f9aabcddf41c99b7af2d0ced33e9a3cc (diff)
downloadlinux-sh-5b74c458906fc4a62f932ee8bb801d29baf15fec.tar.gz
rcu: Make ->cpu_no_qs be a union for aggregate OR
This commit converts the rcu_data structure's ->cpu_no_qs field to a union. The bytewise side of this union allows individual access to indications as to whether this CPU needs to find a quiescent state for a normal (.norm) and/or expedited (.exp) grace period. The setwise side of the union allows testing whether or not a quiescent state is needed at all, for either type of grace period. For now, only .norm is used. A later commit will introduce the expedited usage. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu/tree.c')
-rw-r--r--kernel/rcu/tree.c22
1 files changed, 11 insertions, 11 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"));