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Groups > linux.kernel > #1695147
| From | "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH tip/core/rcu 12/15] rcu: Add assertions verifying blocked-tasks list |
| Date | 2017-07-24 23:50 +0200 |
| Message-ID | <u6ToL-2fn-39@gated-at.bofh.it> (permalink) |
| References | <u6ToJ-2fn-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
This commit adds assertions verifying the consistency of the rcu_node
structure's ->blkd_tasks list and its ->gp_tasks, ->exp_tasks, and
->boost_tasks pointers. In particular, the ->blkd_tasks lists must be
empty except for leaf rcu_node structures.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
kernel/rcu/tree.c | 2 ++
kernel/rcu/tree_plugin.h | 11 +++++++++--
2 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 913c90eccd4d..c028eb254704 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2395,6 +2395,8 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp,
return;
}
WARN_ON_ONCE(oldmask); /* Any child must be all zeroed! */
+ WARN_ON_ONCE(rnp->level != rcu_num_lvls - 1 &&
+ rcu_preempt_blocked_readers_cgp(rnp));
rnp->qsmask &= ~mask;
trace_rcu_quiescent_state_report(rsp->name, rnp->gpnum,
mask, rnp->qsmask, rnp->level,
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 3e3f92e981a1..eadf8b95b5e9 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -180,6 +180,8 @@ static void rcu_preempt_ctxt_queue(struct rcu_node *rnp, struct rcu_data *rdp)
struct task_struct *t = current;
lockdep_assert_held(&rnp->lock);
+ WARN_ON_ONCE(rdp->mynode != rnp);
+ WARN_ON_ONCE(rnp->level != rcu_num_lvls - 1);
/*
* Decide where to queue the newly blocked task. In theory,
@@ -261,6 +263,10 @@ static void rcu_preempt_ctxt_queue(struct rcu_node *rnp, struct rcu_data *rdp)
rnp->gp_tasks = &t->rcu_node_entry;
if (!rnp->exp_tasks && (blkd_state & RCU_EXP_BLKD))
rnp->exp_tasks = &t->rcu_node_entry;
+ WARN_ON_ONCE(!(blkd_state & RCU_GP_BLKD) !=
+ !(rnp->qsmask & rdp->grpmask));
+ WARN_ON_ONCE(!(blkd_state & RCU_EXP_BLKD) !=
+ !(rnp->expmask & rdp->grpmask));
raw_spin_unlock_rcu_node(rnp); /* interrupts remain disabled. */
/*
@@ -482,6 +488,7 @@ void rcu_read_unlock_special(struct task_struct *t)
rnp = t->rcu_blocked_node;
raw_spin_lock_rcu_node(rnp); /* irqs already disabled. */
WARN_ON_ONCE(rnp != t->rcu_blocked_node);
+ WARN_ON_ONCE(rnp->level != rcu_num_lvls - 1);
empty_norm = !rcu_preempt_blocked_readers_cgp(rnp);
empty_exp = sync_rcu_preempt_exp_done(rnp);
smp_mb(); /* ensure expedited fastpath sees end of RCU c-s. */
@@ -495,10 +502,10 @@ void rcu_read_unlock_special(struct task_struct *t)
if (&t->rcu_node_entry == rnp->exp_tasks)
rnp->exp_tasks = np;
if (IS_ENABLED(CONFIG_RCU_BOOST)) {
- if (&t->rcu_node_entry == rnp->boost_tasks)
- rnp->boost_tasks = np;
/* Snapshot ->boost_mtx ownership w/rnp->lock held. */
drop_boost_mutex = rt_mutex_owner(&rnp->boost_mtx) == t;
+ if (&t->rcu_node_entry == rnp->boost_tasks)
+ rnp->boost_tasks = np;
}
/*
--
2.5.2
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[PATCH tip/core/rcu 0/15] General fixes "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-24 23:50 +0200
[PATCH tip/core/rcu 04/15] rcu: Create reasonable API for do_exit() TASKS_RCU processing "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-24 23:50 +0200
[PATCH tip/core/rcu 09/15] rcu: use idle versions of swait to make idle-hack clear "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-24 23:50 +0200
[PATCH tip/core/rcu 02/15] rcu: Use timer as backstop for NOCB deferred wakeups "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-24 23:50 +0200
Re: [PATCH tip/core/rcu 02/15] rcu: Use timer as backstop for NOCB deferred wakeups Steven Rostedt <rostedt@goodmis.org> - 2017-07-25 20:20 +0200
Re: [PATCH tip/core/rcu 02/15] rcu: Use timer as backstop for NOCB deferred wakeups "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-25 21:20 +0200
Re: [PATCH tip/core/rcu 02/15] rcu: Use timer as backstop for NOCB deferred wakeups Steven Rostedt <rostedt@goodmis.org> - 2017-07-26 00:20 +0200
Re: [PATCH tip/core/rcu 02/15] rcu: Use timer as backstop for NOCB deferred wakeups "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-26 02:10 +0200
Re: [PATCH tip/core/rcu 02/15] rcu: Use timer as backstop for NOCB deferred wakeups Steven Rostedt <rostedt@goodmis.org> - 2017-07-26 23:20 +0200
Re: [PATCH tip/core/rcu 02/15] rcu: Use timer as backstop for NOCB deferred wakeups "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-26 23:50 +0200
Re: [PATCH tip/core/rcu 02/15] rcu: Use timer as backstop for NOCB deferred wakeups Steven Rostedt <rostedt@goodmis.org> - 2017-07-27 01:10 +0200
Re: [PATCH tip/core/rcu 02/15] rcu: Use timer as backstop for NOCB deferred wakeups "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-27 19:40 +0200
[PATCH tip/core/rcu 10/15] rcu: Add TPS() protection for _rcu_barrier_trace strings "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-24 23:50 +0200
Re: [PATCH tip/core/rcu 10/15] rcu: Add TPS() protection for _rcu_barrier_trace strings Steven Rostedt <rostedt@goodmis.org> - 2017-07-28 03:50 +0200
[PATCH tip/core/rcu 14/15] rcu: Add warning to rcu_idle_enter() for irqs enabled "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-24 23:50 +0200
[PATCH tip/core/rcu 01/15] sched,rcu: Make cond_resched() provide RCU quiescent state "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-24 23:50 +0200
[PATCH tip/core/rcu 08/15] swait: add idle variants which don't contribute to load average "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-24 23:50 +0200
[PATCH tip/core/rcu 15/15] rcu: Remove exports from rcu_idle_exit() and rcu_idle_enter() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-24 23:50 +0200
[PATCH tip/core/rcu 03/15] rcu: Drive TASKS_RCU directly off of PREEMPT "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-24 23:50 +0200
Re: [PATCH tip/core/rcu 03/15] rcu: Drive TASKS_RCU directly off of PREEMPT Steven Rostedt <rostedt@goodmis.org> - 2017-07-25 20:20 +0200
Re: [PATCH tip/core/rcu 03/15] rcu: Drive TASKS_RCU directly off of PREEMPT "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-25 21:20 +0200
[PATCH tip/core/rcu 12/15] rcu: Add assertions verifying blocked-tasks list "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-24 23:50 +0200
[PATCH tip/core/rcu 05/15] rcu: Add TPS() to event-traced strings "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-24 23:50 +0200
Re: [PATCH tip/core/rcu 05/15] rcu: Add TPS() to event-traced strings Steven Rostedt <rostedt@goodmis.org> - 2017-07-28 03:40 +0200
[PATCH tip/core/rcu 06/15] rcu: Move rcu.h to new trivial-function style "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-07-24 23:50 +0200
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