The following commit has been merged into the core/rcu branch of tip:
Commit-ID: 277ffe1b709280856391663c2ca5685a28308fc5
Gitweb: https://git.kernel.org/tip/277ffe1b709280856391663c2ca5685a28308fc5
Author: Zhouyi Zhou <zhouzhouyi@xxxxxxxxx>
AuthorDate: Tue, 30 Mar 2021 13:47:42 -07:00
Committer: Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Mon, 10 May 2021 16:22:53 -07:00
rcu: Improve tree.c comments and add code cleanups
This commit cleans up some comments and code in kernel/rcu/tree.c.
Signed-off-by: Zhouyi Zhou <zhouzhouyi@xxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/rcu/tree.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index f6543b8..06f3de9 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -202,7 +202,7 @@ EXPORT_SYMBOL_GPL(rcu_get_gp_kthreads_prio);
* the need for long delays to increase some race probabilities with the
* need for fast grace periods to increase other race probabilities.
*/
-#define PER_RCU_NODE_PERIOD 3 /* Number of grace periods between delays. */
+#define PER_RCU_NODE_PERIOD 3 /* Number of grace periods between delays for debugging. */
/*
* Compute the mask of online CPUs for the specified rcu_node structure.
@@ -937,7 +937,7 @@ EXPORT_SYMBOL_GPL(rcu_idle_exit);
*/
void noinstr rcu_user_exit(void)
{
- rcu_eqs_exit(1);
+ rcu_eqs_exit(true);
}
/**
@@ -1203,7 +1203,7 @@ EXPORT_SYMBOL_GPL(rcu_lockdep_current_cpu_online);
#endif /* #if defined(CONFIG_PROVE_RCU) && defined(CONFIG_HOTPLUG_CPU) */
/*
- * We are reporting a quiescent state on behalf of some other CPU, so
+ * When trying to report a quiescent state on behalf of some other CPU,
* it is our responsibility to check for and handle potential overflow
* of the rcu_node ->gp_seq counter with respect to the rcu_data counters.
* After all, the CPU might be in deep idle state, and thus executing no
@@ -2607,7 +2607,7 @@ static void rcu_do_batch(struct rcu_data *rdp)
* state, for example, user mode or idle loop. It also schedules RCU
* core processing. If the current grace period has gone on too long,
* it will ask the scheduler to manufacture a context switch for the sole
- * purpose of providing a providing the needed quiescent state.
+ * purpose of providing the needed quiescent state.
*/
void rcu_sched_clock_irq(int user)
{
@@ -3236,7 +3236,7 @@ put_cached_bnode(struct kfree_rcu_cpu *krcp,
/*
* This function is invoked in workqueue context after a grace period.
- * It frees all the objects queued on ->bhead_free or ->head_free.
+ * It frees all the objects queued on ->bkvhead_free or ->head_free.
*/
static void kfree_rcu_work(struct work_struct *work)
{
@@ -3263,7 +3263,7 @@ static void kfree_rcu_work(struct work_struct *work)
krwp->head_free = NULL;
raw_spin_unlock_irqrestore(&krcp->lock, flags);
- // Handle two first channels.
+ // Handle the first two channels.
for (i = 0; i < FREE_N_CHANNELS; i++) {
for (; bkvhead[i]; bkvhead[i] = bnext) {
bnext = bkvhead[i]->next;
@@ -3530,11 +3530,11 @@ add_ptr_to_bulk_krc_lock(struct kfree_rcu_cpu **krcp,
}
/*
- * Queue a request for lazy invocation of appropriate free routine after a
- * grace period. Please note there are three paths are maintained, two are the
- * main ones that use array of pointers interface and third one is emergency
- * one, that is used only when the main path can not be maintained temporary,
- * due to memory pressure.
+ * Queue a request for lazy invocation of the appropriate free routine
+ * after a grace period. Please note that three paths are maintained,
+ * two for the common case using arrays of pointers and a third one that
+ * is used only when the main paths cannot be used, for example, due to
+ * memory pressure.
*
* Each kvfree_call_rcu() request is added to a batch. The batch will be drained
* every KFREE_DRAIN_JIFFIES number of jiffies. All the objects in the batch will
@@ -4708,7 +4708,7 @@ void __init rcu_init(void)
rcutree_online_cpu(cpu);
}
- /* Create workqueue for expedited GPs and for Tree SRCU. */
+ /* Create workqueue for Tree SRCU and for expedited GPs. */
rcu_gp_wq = alloc_workqueue("rcu_gp", WQ_MEM_RECLAIM, 0);
WARN_ON(!rcu_gp_wq);
rcu_par_gp_wq = alloc_workqueue("rcu_par_gp", WQ_MEM_RECLAIM, 0);
|