}
/*
- * Advance this CPU's callbacks, but only if the current grace period
- * has ended. This may be called only from the CPU to whom the rdp
- * belongs. In addition, the corresponding leaf rcu_node structure's
- * ->lock must be held by the caller, with irqs disabled.
+ * Update CPU-local rcu_data state to record the beginnings and ends of
+ * grace periods. The caller must hold the ->lock of the leaf rcu_node
+ * structure corresponding to the current CPU, and must have irqs disabled.
*/
-static void
-__rcu_process_gp_end(struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp)
+static void __note_gp_changes(struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp)
{
- /* Did another grace period end? */
+ /* Handle the ends of any preceding grace periods first. */
if (rdp->completed == rnp->completed) {
- /* No, so just accelerate recent callbacks. */
+ /* No grace period end, so just accelerate recent callbacks. */
rcu_accelerate_cbs(rsp, rnp, rdp);
} else {
/* Remember that we saw this grace-period completion. */
rdp->completed = rnp->completed;
trace_rcu_grace_period(rsp->name, rdp->gpnum, "cpuend");
-
- /*
- * If we were in an extended quiescent state, we may have
- * missed some grace periods that others CPUs handled on
- * our behalf. Catch up with this state to avoid noting
- * spurious new grace periods. If another grace period
- * has started, then rnp->gpnum will have advanced, so
- * we will detect this later on. Of course, any quiescent
- * states we found for the old GP are now invalid.
- */
- if (ULONG_CMP_LT(rdp->gpnum, rdp->completed)) {
- rdp->gpnum = rdp->completed;
- rdp->passed_quiesce = 0;
- }
-
- /*
- * If RCU does not need a quiescent state from this CPU,
- * then make sure that this CPU doesn't go looking for one.
- */
- if ((rnp->qsmask & rdp->grpmask) == 0)
- rdp->qs_pending = 0;
}
-}
-
-/*
- * Update CPU-local rcu_data state to record the newly noticed grace period.
- * This is used both when we started the grace period and when we notice
- * that someone else started the grace period. The caller must hold the
- * ->lock of the leaf rcu_node structure corresponding to the current CPU,
- * and must have irqs disabled.
- */
-static void __note_gp_changes(struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp)
-{
- /* Handle the ends of any preceding grace periods first. */
- __rcu_process_gp_end(rsp, rnp, rdp);
if (rdp->gpnum != rnp->gpnum) {
/*
raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
-/*
- * Advance this CPU's callbacks, but only if the current grace period
- * has ended. This may be called only from the CPU to whom the rdp
- * belongs.
- */
-static void
-rcu_process_gp_end(struct rcu_state *rsp, struct rcu_data *rdp)
-{
- unsigned long flags;
- struct rcu_node *rnp;
-
- local_irq_save(flags);
- rnp = rdp->mynode;
- if (rdp->completed == ACCESS_ONCE(rnp->completed) || /* outside lock. */
- !raw_spin_trylock(&rnp->lock)) { /* irqs already off, so later. */
- local_irq_restore(flags);
- return;
- }
- __rcu_process_gp_end(rsp, rnp, rdp);
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
-}
-
-/*
- * Did someone else start a new RCU grace period start since we last
- * checked? Update local state appropriately if so. Must be called
- * on the CPU corresponding to rdp.
- */
-static int
-check_for_new_grace_period(struct rcu_state *rsp, struct rcu_data *rdp)
-{
- unsigned long flags;
- int ret = 0;
-
- local_irq_save(flags);
- if (rdp->gpnum != rsp->gpnum) {
- note_gp_changes(rsp, rdp);
- ret = 1;
- }
- local_irq_restore(flags);
- return ret;
-}
-
-/*
- * Do per-CPU grace-period initialization for running CPU. The caller
- * must hold the lock of the leaf rcu_node structure corresponding to
- * this CPU.
- */
-static void
-rcu_start_gp_per_cpu(struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp)
-{
- /* Prior grace period ended, so advance callbacks for current CPU. */
- __rcu_process_gp_end(rsp, rnp, rdp);
-
- /* Set state so that this CPU will detect the next quiescent state. */
- __note_gp_changes(rsp, rnp, rdp);
-}
-
/*
* Initialize a new grace period.
*/
WARN_ON_ONCE(rnp->completed != rsp->completed);
ACCESS_ONCE(rnp->completed) = rsp->completed;
if (rnp == rdp->mynode)
- rcu_start_gp_per_cpu(rsp, rnp, rdp);
+ __note_gp_changes(rsp, rnp, rdp);
rcu_preempt_boost_start_gp(rnp);
trace_rcu_grace_period_init(rsp->name, rnp->gpnum,
rnp->level, rnp->grplo,
ACCESS_ONCE(rnp->completed) = rsp->gpnum;
rdp = this_cpu_ptr(rsp->rda);
if (rnp == rdp->mynode)
- __rcu_process_gp_end(rsp, rnp, rdp);
+ __note_gp_changes(rsp, rnp, rdp);
nocb += rcu_future_gp_cleanup(rsp, rnp);
raw_spin_unlock_irq(&rnp->lock);
cond_resched();
static void
rcu_check_quiescent_state(struct rcu_state *rsp, struct rcu_data *rdp)
{
- /* If there is now a new grace period, record and return. */
- if (check_for_new_grace_period(rsp, rdp))
- return;
+ /* Check for grace-period ends and beginnings. */
+ note_gp_changes(rsp, rdp);
/*
* Does this CPU still need to do its part for current grace period?
WARN_ON_ONCE(rdp->beenonline == 0);
- /* Handle the end of a grace period that some other CPU ended. */
- rcu_process_gp_end(rsp, rdp);
-
/* Update RCU state based on any recent quiescent states. */
rcu_check_quiescent_state(rsp, rdp);
if (unlikely(rdp->qlen > rdp->qlen_last_fqs_check + qhimark)) {
/* Are we ignoring a completed grace period? */
- rcu_process_gp_end(rsp, rdp);
- check_for_new_grace_period(rsp, rdp);
+ note_gp_changes(rsp, rdp);
/* Start a new grace period if one not already started. */
if (!rcu_gp_in_progress(rsp)) {
projects / karo-tx-linux.git / blobdiff