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);
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