From: "Paul E. McKenney" <paulmck@linux.ibm.com>
To: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, mingo@kernel.org,
jiangshanlai@gmail.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,
fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org,
Neeraj Upadhyay <neeraju@codeaurora.org>,
"Paul E . McKenney" <paulmck@linux.ibm.com>
Subject: [PATCH tip/core/rcu 11/18] rcu: Fix self-wakeups for grace-period kthread
Date: Tue, 26 Mar 2019 16:13:07 -0700 [thread overview]
Message-ID: <20190326231314.19518-11-paulmck@linux.ibm.com> (raw)
In-Reply-To: <20190326231253.GA18343@linux.ibm.com>
From: Neeraj Upadhyay <neeraju@codeaurora.org>
The current rcu_gp_kthread_wake() function uses in_interrupt()
and thus does a self-wakeup from all interrupt contexts, including
the pointless case where the GP kthread happens to be running with
bottom halves disabled, along with the impossible case where the GP
kthread is running within an NMI handler (you are not supposed to invoke
rcu_gp_kthread_wake() from within an NMI handler. This commit therefore
replaces the in_interrupt() with in_irq(), so that the self-wakeups
happen only from handlers for hardware interrupts and softirqs.
This also makes the code match the comment.
Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/rcu/tree.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 5aefd36ac648..139fa1f5c537 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1585,7 +1585,7 @@ static bool rcu_future_gp_cleanup(struct rcu_node *rnp)
static void rcu_gp_kthread_wake(void)
{
if ((current == rcu_state.gp_kthread &&
- !in_interrupt() && !in_serving_softirq()) ||
+ !in_irq() && !in_serving_softirq()) ||
!READ_ONCE(rcu_state.gp_flags) ||
!rcu_state.gp_kthread)
return;
--
2.17.1
next prev parent reply other threads:[~2019-03-26 23:13 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-26 23:12 [PATCH tip/core/rcu 0/18] Miscellaneous fixes for v5.2 Paul E. McKenney
2019-03-26 23:12 ` [PATCH tip/core/rcu 01/18] rcu: Unconditionally expedite during suspend/hibernate Paul E. McKenney
2019-03-26 23:12 ` [PATCH tip/core/rcu 02/18] rcu: Avoid unnecessary softirq when system is idle Paul E. McKenney
2019-03-26 23:12 ` [PATCH tip/core/rcu 03/18] rcu: rcu_qs -- Use raise_softirq_irqoff to not save irqs twice Paul E. McKenney
2019-03-26 23:13 ` [PATCH tip/core/rcu 04/18] rcu: Make exit_rcu() handle non-preempted RCU readers Paul E. McKenney
2019-03-26 23:13 ` [PATCH tip/core/rcu 05/18] rcu: Set rcutree.kthread_prio sysfs access to read-only Paul E. McKenney
2019-03-26 23:13 ` [PATCH tip/core/rcu 06/18] MAINTAINERS: RCU now has its own email list Paul E. McKenney
2019-03-26 23:13 ` [PATCH tip/core/rcu 07/18] MAINTAINERS: Add -rcu branch name ("dev") Paul E. McKenney
2019-03-26 23:13 ` [PATCH tip/core/rcu 08/18] rcu: Move common code out of if-else block Paul E. McKenney
2019-03-26 23:13 ` [PATCH tip/core/rcu 09/18] rcu: Allow rcu_nocbs= to specify all CPUs Paul E. McKenney
2019-03-26 23:13 ` [PATCH tip/core/rcu 10/18] rcu: Report error for bad rcu_nocbs= parameter values Paul E. McKenney
2019-03-26 23:13 ` Paul E. McKenney [this message]
2019-03-26 23:13 ` [PATCH tip/core/rcu 12/18] rcu: Default jiffies_to_sched_qs to jiffies_till_sched_qs Paul E. McKenney
2019-03-26 23:13 ` [PATCH tip/core/rcu 13/18] rcu: Do a single rhp->func read in rcu_head_after_call_rcu() Paul E. McKenney
2019-03-26 23:13 ` [PATCH tip/core/rcu 14/18] rcu: Update jiffies_to_sched_qs and adjust_jiffies_till_sched_qs() comments Paul E. McKenney
2019-03-26 23:13 ` [PATCH tip/core/rcu 15/18] rcu: Fix force_qs_rnp() header comment Paul E. McKenney
2019-03-26 23:13 ` [PATCH tip/core/rcu 16/18] rcu: Eliminate redundant NULL-pointer check Paul E. McKenney
2019-03-26 23:13 ` [PATCH tip/core/rcu 17/18] rcu: Fix typo in tree_exp.h comment Paul E. McKenney
2019-03-26 23:13 ` [PATCH tip/core/rcu 18/18] rcu: Correct READ_ONCE()/WRITE_ONCE() for ->rcu_read_unlock_special Paul E. McKenney
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