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-rw-r--r--kernel/rcutree.c66
-rw-r--r--kernel/rcutree.h3
-rw-r--r--kernel/rcutree_plugin.h12
3 files changed, 45 insertions, 36 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 4ca7e0292fd..a9f51031d3e 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -740,11 +740,13 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
}
/*
- * Clean up after the prior grace period and let rcu_start_gp() start up
- * the next grace period if one is needed. Note that the caller must
- * hold rnp->lock, as required by rcu_start_gp(), which will release it.
+ * Report a full set of quiescent states to the specified rcu_state
+ * data structure. This involves cleaning up after the prior grace
+ * period and letting rcu_start_gp() start up the next grace period
+ * if one is needed. Note that the caller must hold rnp->lock, as
+ * required by rcu_start_gp(), which will release it.
*/
-static void cpu_quiet_msk_finish(struct rcu_state *rsp, unsigned long flags)
+static void rcu_report_qs_rsp(struct rcu_state *rsp, unsigned long flags)
__releases(rcu_get_root(rsp)->lock)
{
WARN_ON_ONCE(!rcu_gp_in_progress(rsp));
@@ -754,15 +756,16 @@ static void cpu_quiet_msk_finish(struct rcu_state *rsp, unsigned long flags)
}
/*
- * Similar to cpu_quiet(), for which it is a helper function. Allows
- * a group of CPUs to be quieted at one go, though all the CPUs in the
- * group must be represented by the same leaf rcu_node structure.
- * That structure's lock must be held upon entry, and it is released
- * before return.
+ * Similar to rcu_report_qs_rdp(), for which it is a helper function.
+ * Allows quiescent states for a group of CPUs to be reported at one go
+ * to the specified rcu_node structure, though all the CPUs in the group
+ * must be represented by the same rcu_node structure (which need not be
+ * a leaf rcu_node structure, though it often will be). That structure's
+ * lock must be held upon entry, and it is released before return.
*/
static void
-cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp,
- unsigned long flags)
+rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp,
+ struct rcu_node *rnp, unsigned long flags)
__releases(rnp->lock)
{
struct rcu_node *rnp_c;
@@ -798,21 +801,23 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp,
/*
* Get here if we are the last CPU to pass through a quiescent
- * state for this grace period. Invoke cpu_quiet_msk_finish()
+ * state for this grace period. Invoke rcu_report_qs_rsp()
* to clean up and start the next grace period if one is needed.
*/
- cpu_quiet_msk_finish(rsp, flags); /* releases rnp->lock. */
+ rcu_report_qs_rsp(rsp, flags); /* releases rnp->lock. */
}
/*
- * Record a quiescent state for the specified CPU, which must either be
- * the current CPU. The lastcomp argument is used to make sure we are
- * still in the grace period of interest. We don't want to end the current
- * grace period based on quiescent states detected in an earlier grace
- * period!
+ * Record a quiescent state for the specified CPU to that CPU's rcu_data
+ * structure. This must be either called from the specified CPU, or
+ * called when the specified CPU is known to be offline (and when it is
+ * also known that no other CPU is concurrently trying to help the offline
+ * CPU). The lastcomp argument is used to make sure we are still in the
+ * grace period of interest. We don't want to end the current grace period
+ * based on quiescent states detected in an earlier grace period!
*/
static void
-cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp)
+rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp)
{
unsigned long flags;
unsigned long mask;
@@ -827,8 +832,8 @@ cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp)
* The race with GP start is resolved by the fact that we
* hold the leaf rcu_node lock, so that the per-CPU bits
* cannot yet be initialized -- so we would simply find our
- * CPU's bit already cleared in cpu_quiet_msk() if this race
- * occurred.
+ * CPU's bit already cleared in rcu_report_qs_rnp() if this
+ * race occurred.
*/
rdp->passed_quiesc = 0; /* try again later! */
spin_unlock_irqrestore(&rnp->lock, flags);
@@ -846,7 +851,7 @@ cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp)
*/
rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
- cpu_quiet_msk(mask, rsp, rnp, flags); /* releases rnp->lock */
+ rcu_report_qs_rnp(mask, rsp, rnp, flags); /* rlses rnp->lock */
}
}
@@ -877,8 +882,11 @@ rcu_check_quiescent_state(struct rcu_state *rsp, struct rcu_data *rdp)
if (!rdp->passed_quiesc)
return;
- /* Tell RCU we are done (but cpu_quiet() will be the judge of that). */
- cpu_quiet(rdp->cpu, rsp, rdp, rdp->passed_quiesc_completed);
+ /*
+ * Tell RCU we are done (but rcu_report_qs_rdp() will be the
+ * judge of that).
+ */
+ rcu_report_qs_rdp(rdp->cpu, rsp, rdp, rdp->passed_quiesc_completed);
}
#ifdef CONFIG_HOTPLUG_CPU
@@ -968,13 +976,13 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
/*
* We still hold the leaf rcu_node structure lock here, and
* irqs are still disabled. The reason for this subterfuge is
- * because invoking task_quiet() with ->onofflock held leads
- * to deadlock.
+ * because invoking rcu_report_unblock_qs_rnp() with ->onofflock
+ * held leads to deadlock.
*/
spin_unlock(&rsp->onofflock); /* irqs remain disabled. */
rnp = rdp->mynode;
if (need_quiet)
- task_quiet(rnp, flags);
+ rcu_report_unblock_qs_rnp(rnp, flags);
else
spin_unlock_irqrestore(&rnp->lock, flags);
@@ -1164,8 +1172,8 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp,
}
if (mask != 0 && rnp->completed == lastcomp) {
- /* cpu_quiet_msk() releases rnp->lock. */
- cpu_quiet_msk(mask, rsp, rnp, flags);
+ /* rcu_report_qs_rnp() releases rnp->lock. */
+ rcu_report_qs_rnp(mask, rsp, rnp, flags);
continue;
}
spin_unlock_irqrestore(&rnp->lock, flags);
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index a81188c4292..8bb03cb0744 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -306,7 +306,8 @@ long rcu_batches_completed(void);
static void rcu_preempt_note_context_switch(int cpu);
static int rcu_preempted_readers(struct rcu_node *rnp);
#ifdef CONFIG_HOTPLUG_CPU
-static void task_quiet(struct rcu_node *rnp, unsigned long flags);
+static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp,
+ unsigned long flags);
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
static void rcu_print_task_stall(struct rcu_node *rnp);
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 1d295c789d3..c9f0c975c00 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -167,7 +167,7 @@ static int rcu_preempted_readers(struct rcu_node *rnp)
* irqs disabled, and this lock is released upon return, but irqs remain
* disabled.
*/
-static void task_quiet(struct rcu_node *rnp, unsigned long flags)
+static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags)
__releases(rnp->lock)
{
unsigned long mask;
@@ -185,7 +185,7 @@ static void task_quiet(struct rcu_node *rnp, unsigned long flags)
* or tasks were kicked up to root rcu_node due to
* CPUs going offline.
*/
- cpu_quiet_msk_finish(&rcu_preempt_state, flags);
+ rcu_report_qs_rsp(&rcu_preempt_state, flags);
return;
}
@@ -193,7 +193,7 @@ static void task_quiet(struct rcu_node *rnp, unsigned long flags)
mask = rnp->grpmask;
spin_unlock(&rnp->lock); /* irqs remain disabled. */
spin_lock(&rnp_p->lock); /* irqs already disabled. */
- cpu_quiet_msk(mask, &rcu_preempt_state, rnp_p, flags);
+ rcu_report_qs_rnp(mask, &rcu_preempt_state, rnp_p, flags);
}
/*
@@ -253,12 +253,12 @@ static void rcu_read_unlock_special(struct task_struct *t)
/*
* If this was the last task on the current list, and if
* we aren't waiting on any CPUs, report the quiescent state.
- * Note that task_quiet() releases rnp->lock.
+ * Note that rcu_report_unblock_qs_rnp() releases rnp->lock.
*/
if (empty)
spin_unlock_irqrestore(&rnp->lock, flags);
else
- task_quiet(rnp, flags);
+ rcu_report_unblock_qs_rnp(rnp, flags);
} else {
local_irq_restore(flags);
}
@@ -566,7 +566,7 @@ static int rcu_preempted_readers(struct rcu_node *rnp)
#ifdef CONFIG_HOTPLUG_CPU
/* Because preemptible RCU does not exist, no quieting of tasks. */
-static void task_quiet(struct rcu_node *rnp, unsigned long flags)
+static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags)
{
spin_unlock_irqrestore(&rnp->lock, flags);
}