From: Paul E. McKenney <paulmck@kernel.org>
Date: Thu, 24 Feb 2022 17:38:46 +0000 (-0800)
Subject: Merge branches 'exp.2022.02.24a', 'fixes.2022.02.14a', 'rcu_barrier.2022.02.08a'... 
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=d5578190bed3d110203e3b6b29c5a7a39d51c6c0;p=linux.git

Merge branches 'exp.2022.02.24a', 'fixes.2022.02.14a', 'rcu_barrier.2022.02.08a', 'rcu-tasks.2022.02.08a', 'rt.2022.02.01b', 'torture.2022.02.01b' and 'torturescript.2022.02.08a' into HEAD

exp.2022.02.24a: Expedited grace-period updates.
fixes.2022.02.14a: Miscellaneous fixes.
rcu_barrier.2022.02.08a: Make rcu_barrier() no longer exclude CPU hotplug.
rcu-tasks.2022.02.08a: RCU-tasks updates.
rt.2022.02.01b: Real-time-related updates.
torture.2022.02.01b: Torture-test updates.
torturescript.2022.02.08a: Torture-test scripting updates.
---

d5578190bed3d110203e3b6b29c5a7a39d51c6c0
diff --cc kernel/rcu/tree.c
index a4c25a6283b0b,ca8d7dd026eeb,1d3507d563db1,a4c25a6283b0b,bd9b2af247abd,a4c25a6283b0b,a4c25a6283b0b..acf3985268183
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@@@@@@@ -4056,29 -4049,29 -4087,31 -4056,29 -4059,29 -4056,29 -4056,29 +4083,31 @@@@@@@@ void rcu_barrier(void
       	 */
       	for_each_possible_cpu(cpu) {
       		rdp = per_cpu_ptr(&rcu_data, cpu);
-- ----		if (cpu_is_offline(cpu) &&
-- ----		    !rcu_rdp_is_offloaded(rdp))
++ ++++retry:
++ ++++		if (smp_load_acquire(&rdp->barrier_seq_snap) == gseq)
    +  			continue;
-- - --		if (rcu_segcblist_n_cbs(&rdp->cblist) && cpu_online(cpu)) {
-- - --			rcu_barrier_trace(TPS("OnlineQ"), cpu,
-- - --					  rcu_state.barrier_sequence);
-- - --			smp_call_function_single(cpu, rcu_barrier_func, (void *)cpu, 1);
-- - --		} else if (rcu_segcblist_n_cbs(&rdp->cblist) &&
-- - --			   cpu_is_offline(cpu)) {
-- - --			rcu_barrier_trace(TPS("OfflineNoCBQ"), cpu,
-- - --					  rcu_state.barrier_sequence);
-- - --			local_irq_disable();
-- - --			rcu_barrier_func((void *)cpu);
-- - --			local_irq_enable();
-- - --		} else if (cpu_is_offline(cpu)) {
-- - --			rcu_barrier_trace(TPS("OfflineNoCBNoQ"), cpu,
-- - --					  rcu_state.barrier_sequence);
-- - --		} else {
-- - --			rcu_barrier_trace(TPS("OnlineNQ"), cpu,
-- - --					  rcu_state.barrier_sequence);
++ ++++		raw_spin_lock_irqsave(&rcu_state.barrier_lock, flags);
++ ++++		if (!rcu_segcblist_n_cbs(&rdp->cblist)) {
++ ++++			WRITE_ONCE(rdp->barrier_seq_snap, gseq);
++ ++++			raw_spin_unlock_irqrestore(&rcu_state.barrier_lock, flags);
++ ++++			rcu_barrier_trace(TPS("NQ"), cpu, rcu_state.barrier_sequence);
++ + ++			continue;
    -  		if (rcu_segcblist_n_cbs(&rdp->cblist) && cpu_online(cpu)) {
    -  			rcu_barrier_trace(TPS("OnlineQ"), cpu,
    -  					  rcu_state.barrier_sequence);
    -  			smp_call_function_single(cpu, rcu_barrier_func, (void *)cpu, 1);
    -  		} else if (rcu_segcblist_n_cbs(&rdp->cblist) &&
    -  			   cpu_is_offline(cpu)) {
    -  			rcu_barrier_trace(TPS("OfflineNoCBQ"), cpu,
    -  					  rcu_state.barrier_sequence);
    -  			local_irq_disable();
    -  			rcu_barrier_func((void *)cpu);
    -  			local_irq_enable();
    -  		} else if (cpu_is_offline(cpu)) {
    -  			rcu_barrier_trace(TPS("OfflineNoCBNoQ"), cpu,
    -  					  rcu_state.barrier_sequence);
    -  		} else {
    -  			rcu_barrier_trace(TPS("OnlineNQ"), cpu,
    -  					  rcu_state.barrier_sequence);
++ + ++		}
++ ++++		if (!rcu_rdp_cpu_online(rdp)) {
++ ++++			rcu_barrier_entrain(rdp);
++ ++++			WARN_ON_ONCE(READ_ONCE(rdp->barrier_seq_snap) != gseq);
++ ++++			raw_spin_unlock_irqrestore(&rcu_state.barrier_lock, flags);
++ ++++			rcu_barrier_trace(TPS("OfflineNoCBQ"), cpu, rcu_state.barrier_sequence);
++ ++++			continue;
++ ++++		}
++ ++++		raw_spin_unlock_irqrestore(&rcu_state.barrier_lock, flags);
++ ++++		if (smp_call_function_single(cpu, rcu_barrier_handler, (void *)cpu, 1)) {
++ ++++			schedule_timeout_uninterruptible(1);
++ ++++			goto retry;
    +  		}
++ ++++		WARN_ON_ONCE(READ_ONCE(rdp->barrier_seq_snap) != gseq);
++ ++++		rcu_barrier_trace(TPS("OnlineQ"), cpu, rcu_state.barrier_sequence);
       	}
-- ----	cpus_read_unlock();
       
       	/*
       	 * Now that we have an rcu_barrier_callback() callback on each
diff --cc kernel/rcu/tree_plugin.h
index c5b45c2f68a15,efd0c87d2ffae,d3db2168598ef,c5b45c2f68a15,8167cab1bffc8,c5b45c2f68a15,c5b45c2f68a15..6082dd23408f8
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@@@@@@@ -1172,11 -1172,12 -1170,11 -1172,11 -1175,9 -1172,11 -1172,11 +1173,10 @@@@@@@@ static void rcu_spawn_one_boost_kthread
       	struct sched_param sp;
       	struct task_struct *t;
       
+ +++++	mutex_lock(&rnp->boost_kthread_mutex);
       	if (rnp->boost_kthread_task || !rcu_scheduler_fully_active)
- -----		return;
- -- --
- -- --	rcu_state.boost = 1;
+ +++++		goto out;
       
 -     	rcu_state.boost = 1;
 -     
       	t = kthread_create(rcu_boost_kthread, (void *)rnp,
       			   "rcub/%d", rnp_index);
       	if (WARN_ON_ONCE(IS_ERR(t)))