From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Carsten Emde <C.Emde@osadl.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
John Kacur <jkacur@redhat.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
<stable-rt@vger.kernel.org>
Subject: [PATCH RT 07/10] irqwork: Move irq safe work to irq context
Date: Fri, 26 Feb 2016 16:41:07 -0500 [thread overview]
Message-ID: <20160226214120.131314296@goodmis.org> (raw)
In-Reply-To: 20160226214100.390136141@goodmis.org
[-- Attachment #1: 0007-irqwork-Move-irq-safe-work-to-irq-context.patch --]
[-- Type: text/plain, Size: 2758 bytes --]
3.10.97-rt106-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Thomas Gleixner <tglx@linutronix.de>
On architectures where arch_irq_work_has_interrupt() returns false, we
end up running the irq safe work from the softirq context. That
results in a potential deadlock in the scheduler irq work which
expects that function to be called with interrupts disabled.
Split the irq_work_tick() function into a hard and soft variant. Call
the hard variant from the tick interrupt and add the soft variant to
the timer softirq.
Reported-and-tested-by: Yanjiang Jin <yanjiang.jin@windriver.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable-rt@vger.kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
include/linux/irq_work.h | 6 ++++++
kernel/irq_work.c | 9 +++++++++
kernel/timer.c | 6 ++----
3 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
index 4a8c7a2df480..ccd736ebee9e 100644
--- a/include/linux/irq_work.h
+++ b/include/linux/irq_work.h
@@ -44,4 +44,10 @@ bool irq_work_needs_cpu(void);
static inline bool irq_work_needs_cpu(void) { return false; }
#endif
+#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL)
+void irq_work_tick_soft(void);
+#else
+static inline void irq_work_tick_soft(void) { }
+#endif
+
#endif /* _LINUX_IRQ_WORK_H */
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index af8ceafc94e4..883bb73698b9 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -163,8 +163,17 @@ void irq_work_tick(void)
if (!llist_empty(raised) && !arch_irq_work_has_interrupt())
irq_work_run_list(raised);
+
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL))
+ irq_work_run_list(this_cpu_ptr(&lazy_list));
+}
+
+#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL)
+void irq_work_tick_soft(void)
+{
irq_work_run_list(this_cpu_ptr(&lazy_list));
}
+#endif
/*
* Synchronize against the irq_work @entry, ensures the entry is not
diff --git a/kernel/timer.c b/kernel/timer.c
index ff272e20ee0c..2fd6ea5c6519 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1450,7 +1450,7 @@ void update_process_times(int user_tick)
scheduler_tick();
run_local_timers();
rcu_check_callbacks(cpu, user_tick);
-#if defined(CONFIG_IRQ_WORK) && !defined(CONFIG_PREEMPT_RT_FULL)
+#if defined(CONFIG_IRQ_WORK)
if (in_irq())
irq_work_run();
#endif
@@ -1466,9 +1466,7 @@ static void run_timer_softirq(struct softirq_action *h)
hrtimer_run_pending();
-#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL)
- irq_work_tick();
-#endif
+ irq_work_tick_soft();
if (time_after_eq(jiffies, base->timer_jiffies))
__run_timers(base);
--
2.7.0
next prev parent reply other threads:[~2016-02-26 21:41 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-26 21:41 [PATCH RT 00/10] Linux 3.10.97-rt106-rc1 Steven Rostedt
2016-02-26 21:41 ` [PATCH RT 01/10] ARM: smp: Move clear_tasks_mm_cpumask() call to __cpu_die() Steven Rostedt
2016-02-26 21:41 ` [PATCH RT 02/10] rtmutex: Handle non enqueued waiters gracefully Steven Rostedt
2016-02-26 21:41 ` [PATCH RT 03/10] rtmutex: Use chainwalking control enum Steven Rostedt
2016-02-26 21:41 ` [PATCH RT 04/10] dump stack: dont disable preemption during trace Steven Rostedt
2016-02-26 21:41 ` [PATCH RT 05/10] net: Make synchronize_rcu_expedited() conditional on !RT_FULL Steven Rostedt
2016-02-26 21:41 ` [PATCH RT 06/10] net/core/cpuhotplug: Drain input_pkt_queue lockless Steven Rostedt
2016-02-26 21:41 ` Steven Rostedt [this message]
2016-02-26 21:41 ` [PATCH RT 08/10] sched: Introduce the trace_sched_waking tracepoint Steven Rostedt
2016-02-26 21:41 ` [PATCH RT 09/10] rtmutex: Have slowfn of rt_mutex_timed_fastlock() use enum Steven Rostedt
2016-02-26 21:41 ` [PATCH RT 10/10] Linux 3.10.97-rt106-rc1 Steven Rostedt
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