From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sun, 4 Jul 2021 19:58:33 +0000 (-0700)
Subject: Merge branch 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git... 
X-Git-Tag: v5.14-rc1~78
X-Git-Url: https://repo.jachan.dev/linux.git/commitdiff_plain/28e92f990337b8b4c5fdec47667f8b96089c503e

Merge branch 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull RCU updates from Paul McKenney:

 - Bitmap parsing support for "all" as an alias for all bits

 - Documentation updates

 - Miscellaneous fixes, including some that overlap into mm and lockdep

 - kvfree_rcu() updates

 - mem_dump_obj() updates, with acks from one of the slab-allocator
   maintainers

 - RCU NOCB CPU updates, including limited deoffloading

 - SRCU updates

 - Tasks-RCU updates

 - Torture-test updates

* 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (78 commits)
  tasks-rcu: Make show_rcu_tasks_gp_kthreads() be static inline
  rcu-tasks: Make ksoftirqd provide RCU Tasks quiescent states
  rcu: Add missing __releases() annotation
  rcu: Remove obsolete rcu_read_unlock() deadlock commentary
  rcu: Improve comments describing RCU read-side critical sections
  rcu: Create an unrcu_pointer() to remove __rcu from a pointer
  srcu: Early test SRCU polling start
  rcu: Fix various typos in comments
  rcu/nocb: Unify timers
  rcu/nocb: Prepare for fine-grained deferred wakeup
  rcu/nocb: Only cancel nocb timer if not polling
  rcu/nocb: Delete bypass_timer upon nocb_gp wakeup
  rcu/nocb: Cancel nocb_timer upon nocb_gp wakeup
  rcu/nocb: Allow de-offloading rdp leader
  rcu/nocb: Directly call __wake_nocb_gp() from bypass timer
  rcu: Don't penalize priority boosting when there is nothing to boost
  rcu: Point to documentation of ordering guarantees
  rcu: Make rcu_gp_cleanup() be noinline for tracing
  rcu: Restrict RCU_STRICT_GRACE_PERIOD to at most four CPUs
  rcu: Make show_rcu_gp_kthreads() dump rcu_node structures blocking GP
  ...
---

28e92f990337b8b4c5fdec47667f8b96089c503e
diff --cc kernel/rcu/tree_stall.h
index acb2288063b5,f4152aa18f48..3f937b20814f
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@@ -734,21 -793,30 +793,30 @@@ void show_rcu_gp_kthreads(void
  	j = jiffies;
  	ja = j - data_race(rcu_state.gp_activity);
  	jr = j - data_race(rcu_state.gp_req_activity);
+ 	js = j - data_race(rcu_state.gp_start);
  	jw = j - data_race(rcu_state.gp_wake_time);
- 	pr_info("%s: wait state: %s(%d) ->state: %#x delta ->gp_activity %lu ->gp_req_activity %lu ->gp_wake_time %lu ->gp_wake_seq %ld ->gp_seq %ld ->gp_seq_needed %ld ->gp_flags %#x\n",
+ 	pr_info("%s: wait state: %s(%d) ->state: %#lx ->rt_priority %u delta ->gp_start %lu ->gp_activity %lu ->gp_req_activity %lu ->gp_wake_time %lu ->gp_wake_seq %ld ->gp_seq %ld ->gp_seq_needed %ld ->gp_max %lu ->gp_flags %#x\n",
  		rcu_state.name, gp_state_getname(rcu_state.gp_state),
- 		rcu_state.gp_state, t ? t->__state : 0x1ffff,
- 		ja, jr, jw, (long)data_race(rcu_state.gp_wake_seq),
 -		rcu_state.gp_state, t ? t->state : 0x1ffffL, t ? t->rt_priority : 0xffU,
++		rcu_state.gp_state, t ? t->__state : 0x1ffffL, t ? t->rt_priority : 0xffU,
+ 		js, ja, jr, jw, (long)data_race(rcu_state.gp_wake_seq),
  		(long)data_race(rcu_state.gp_seq),
  		(long)data_race(rcu_get_root()->gp_seq_needed),
+ 		data_race(rcu_state.gp_max),
  		data_race(rcu_state.gp_flags));
  	rcu_for_each_node_breadth_first(rnp) {
- 		if (ULONG_CMP_GE(READ_ONCE(rcu_state.gp_seq),
- 				 READ_ONCE(rnp->gp_seq_needed)))
+ 		if (ULONG_CMP_GE(READ_ONCE(rcu_state.gp_seq), READ_ONCE(rnp->gp_seq_needed)) &&
+ 		    !data_race(rnp->qsmask) && !data_race(rnp->boost_tasks) &&
+ 		    !data_race(rnp->exp_tasks) && !data_race(rnp->gp_tasks))
  			continue;
- 		pr_info("\trcu_node %d:%d ->gp_seq %ld ->gp_seq_needed %ld\n",
- 			rnp->grplo, rnp->grphi, (long)data_race(rnp->gp_seq),
- 			(long)data_race(rnp->gp_seq_needed));
+ 		pr_info("\trcu_node %d:%d ->gp_seq %ld ->gp_seq_needed %ld ->qsmask %#lx %c%c%c%c ->n_boosts %ld\n",
+ 			rnp->grplo, rnp->grphi,
+ 			(long)data_race(rnp->gp_seq), (long)data_race(rnp->gp_seq_needed),
+ 			data_race(rnp->qsmask),
+ 			".b"[!!data_race(rnp->boost_kthread_task)],
+ 			".B"[!!data_race(rnp->boost_tasks)],
+ 			".E"[!!data_race(rnp->exp_tasks)],
+ 			".G"[!!data_race(rnp->gp_tasks)],
+ 			data_race(rnp->n_boosts));
  		if (!rcu_is_leaf_node(rnp))
  			continue;
  		for_each_leaf_node_possible_cpu(rnp, cpu) {