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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 10/10] rcu: Initialize tiny RCU stall-warning timeouts at boot
Date: Wed,  7 Jan 2015 09:52:48 -0800	[thread overview]
Message-ID: <1420653168-6434-10-git-send-email-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <1420653168-6434-1-git-send-email-paulmck@linux.vnet.ibm.com>

From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

The current tiny RCU stall-warning code assumes that the jiffies counter
starts at zero, however, it is sometimes initialized to other values,
for example, -30,000.  This commit therefore changes rcu_init() to
invoke reset_cpu_stall_ticks() for both flavors of RCU to initialize
the stall-warning times properly at boot.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
 kernel/rcu/tiny.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index 0db5649f8817..fc0f2c07af3a 100644
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -383,6 +383,8 @@ EXPORT_SYMBOL_GPL(call_rcu_bh);
 void __init rcu_init(void)
 {
 	open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
+	RCU_TRACE(reset_cpu_stall_ticks(&rcu_sched_ctrlblk));
+	RCU_TRACE(reset_cpu_stall_ticks(&rcu_bh_ctrlblk));
 
 	rcu_early_boot_tests();
 }
-- 
1.8.1.5


      parent reply	other threads:[~2015-01-07 17:54 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-07 17:52 [PATCH tip/core/rcu 0/9] Stall-warning changes for 3.20 Paul E. McKenney
2015-01-07 17:52 ` [PATCH tip/core/rcu 01/10] rcu: Set default to RCU_CPU_STALL_INFO=y Paul E. McKenney
2015-01-07 17:52   ` [PATCH tip/core/rcu 02/10] rcutorture: Add checks for stall ending before dump start Paul E. McKenney
2015-01-07 17:52   ` [PATCH tip/core/rcu 03/10] rcu: Make RCU_CPU_STALL_INFO include number of fqs attempts Paul E. McKenney
2015-01-07 17:52   ` [PATCH tip/core/rcu 04/10] rcu: Improve diagnostics for spurious RCU CPU stall warnings Paul E. McKenney
2015-01-07 17:52   ` [PATCH tip/core/rcu 05/10] rcu: Handle gpnum/completed wrap while dyntick idle Paul E. McKenney
2015-01-07 17:52   ` [PATCH tip/core/rcu 06/10] rcu: Run grace-period kthreads at real-time priority Paul E. McKenney
2015-01-07 17:52   ` [PATCH tip/core/rcu 07/10] rcu: Make cond_resched_rcu_qs() apply to normal RCU flavors Paul E. McKenney
2015-01-07 17:52   ` [PATCH tip/core/rcu 08/10] rcu: Add GP-kthread-starvation checks to CPU stall warnings Paul E. McKenney
2015-01-07 17:52   ` [PATCH tip/core/rcu 09/10] rcu: Fix RCU CPU stall detection in tiny implementation Paul E. McKenney
2015-01-07 17:52   ` Paul E. McKenney [this message]

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