From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@kernel.org, laijs@cn.fujitsu.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com,
bobby.prani@gmail.com,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH tip/core/rcu 13/14] rcu: Don't scan root rcu_node structure for stalled tasks
Date: Wed, 7 Jan 2015 09:32:32 -0800 [thread overview]
Message-ID: <1420651953-2651-13-git-send-email-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <1420651953-2651-1-git-send-email-paulmck@linux.vnet.ibm.com>
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Now that blocked tasks are no longer migrated to the root rcu_node
structure, there is no need to scan the root rcu_node structure for
blocked tasks stalling the current grace period. This commit therefore
removes this scan.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
kernel/rcu/tree.c | 9 ---------
1 file changed, 9 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 24d3c67f7be7..4ed2c2842103 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1107,15 +1107,6 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
- /*
- * Now rat on any tasks that got kicked up to the root rcu_node
- * due to CPU offlining.
- */
- rnp = rcu_get_root(rsp);
- raw_spin_lock_irqsave(&rnp->lock, flags);
- ndetected += rcu_print_task_stall(rnp);
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
-
print_cpu_stall_info_end();
for_each_possible_cpu(cpu)
totqlen += per_cpu_ptr(rsp->rda, cpu)->qlen;
--
1.8.1.5
next prev parent reply other threads:[~2015-01-07 17:32 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-07 17:32 [PATCH tip/core/rcu 0/14] Preemptible-RCU updates for 3.20 Paul E. McKenney
2015-01-07 17:32 ` [PATCH tip/core/rcu 01/14] rcu: Protect rcu_boost() lockless accesses with ACCESS_ONCE() Paul E. McKenney
2015-01-07 17:32 ` [PATCH tip/core/rcu 02/14] rcu: Rename "empty" to "empty_norm" in preparation for boost rework Paul E. McKenney
2015-01-07 17:32 ` [PATCH tip/core/rcu 03/14] rcu: Abstract rcu_cleanup_dead_rnp() from rcu_cleanup_dead_cpu() Paul E. McKenney
2015-01-07 17:32 ` [PATCH tip/core/rcu 04/14] rcu: Make rcu_read_unlock_special() propagate ->qsmaskinit bit clearing Paul E. McKenney
2015-01-07 17:32 ` [PATCH tip/core/rcu 05/14] rcu: Don't migrate blocked tasks even if all corresponding CPUs offline Paul E. McKenney
2015-01-07 17:32 ` [PATCH tip/core/rcu 06/14] rcu: Shorten irq-disable region in rcu_cleanup_dead_cpu() Paul E. McKenney
2015-01-07 17:32 ` [PATCH tip/core/rcu 07/14] rcu: Make use of rcu_preempt_has_tasks() Paul E. McKenney
2015-01-07 17:32 ` [PATCH tip/core/rcu 08/14] rcu: Don't spawn rcub kthreads on root rcu_node structure Paul E. McKenney
2015-01-07 17:32 ` [PATCH tip/core/rcu 09/14] rcu: Don't initiate RCU priority boosting on root rcu_node Paul E. McKenney
2015-01-07 17:32 ` [PATCH tip/core/rcu 10/14] rcu: Don't bother affinitying rcub kthreads away from offline CPUs Paul E. McKenney
2015-01-07 17:32 ` [PATCH tip/core/rcu 11/14] rcu: Note quiescent state when CPU goes offline Paul E. McKenney
2015-01-07 17:32 ` [PATCH tip/core/rcu 12/14] rcu: Revert "Allow post-unlock reference for rt_mutex" to avoid priority-inversion Paul E. McKenney
2015-01-07 17:32 ` Paul E. McKenney [this message]
2015-01-07 17:32 ` [PATCH tip/core/rcu 14/14] rcu: Remove redundant callback-list initialization Paul E. McKenney
2015-01-08 9:41 ` [PATCH tip/core/rcu 01/14] rcu: Protect rcu_boost() lockless accesses with ACCESS_ONCE() Peter Zijlstra
2015-01-08 15:22 ` Paul E. McKenney
2015-01-09 6:41 ` Davidlohr Bueso
2015-01-09 13:49 ` Paul E. McKenney
2015-01-09 13:56 ` Peter Zijlstra
2015-01-09 14:07 ` Paul E. McKenney
2015-01-09 16:53 ` Mathieu Desnoyers
2015-01-09 21:58 ` Christian Borntraeger
2015-01-10 0:27 ` Davidlohr Bueso
2015-01-12 8:59 ` Peter Zijlstra
2015-01-12 22:12 ` Paul E. McKenney
2015-01-13 8:18 ` Christian Borntraeger
2015-01-13 9:29 ` Peter Zijlstra
2015-01-13 17:47 ` Paul E. McKenney
2015-01-13 19:12 ` Davidlohr Bueso
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