Dear RT folks!
I'm pleased to announce the v4.16.18-rt12 patch set.
Changes since v4.16.18-rt11:
- Mark RCU's "rcu_iw" irqwork to be invoked in hardirq context as
expected by RCU. Reported by John Ogness.
- Drop the "is_special_task_state()" check from rtmutex's custom
set_state function. This avoids a warning if the sleeping-lock code
is restoring back to this "special" state.
- If a kworker invokes schedule() it is possible that it wakes another
kworker and invokes schedule() again. Try to avoid the second
schedule(). Reported and patched by Daniel Bristot de Oliveira.
- Enable XEN on ARM64. Iain Hunter reported that there are no problems
with it so there is no reason to keep disabled.
Known issues
- A warning triggered in "rcu_note_context_switch" originated from
SyS_timer_gettime(). The issue was always there, it is now
visible. Reported by Grygorii Strashko and Daniel Wagner.
The delta patch against v4.16.18-rt11 is appended below and can be found here:
https://cdn.kernel.org/pub/linux/kernel/projects/rt/4.16/incr/patch-4.16.18-rt11-rt12.patch.xz
You can get this release via the git tree at:
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
v4.16.18-rt12
The RT patch against v4.16.18 can be found here:
https://cdn.kernel.org/pub/linux/kernel/projects/rt/4.16/older/patch-4.16.18-rt12.patch.xz
The split quilt queue is available at:
https://cdn.kernel.org/pub/linux/kernel/projects/rt/4.16/older/patches-4.16.18-rt12.tar.xz
Sebastian
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index d2370c7829451..3a6f0ae739d39 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -861,7 +861,7 @@ config XEN_DOM0
config XEN
bool "Xen guest support on ARM64"
- depends on ARM64 && OF && !PREEMPT_RT_FULL
+ depends on ARM64 && OF
select SWIOTLB_XEN
select PARAVIRT
help
diff --git a/include/linux/sched.h b/include/linux/sched.h
index a0c1c0cae992d..5d5adba0c8ef7 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -131,16 +131,7 @@ struct task_group;
} while (0)
#define __set_current_state_no_track(state_value) \
- do { \
- WARN_ON_ONCE(is_special_task_state(state_value));\
- current->state = (state_value); \
- } while (0)
-
-#define set_current_state_no_track(state_value) \
- do { \
- WARN_ON_ONCE(is_special_task_state(state_value));\
- smp_store_mb(current->state, (state_value)); \
- } while (0)
+ current->state = (state_value);
#define set_special_state(state_value) \
do { \
@@ -196,7 +187,6 @@ struct task_group;
smp_store_mb(current->state, (state_value))
#define __set_current_state_no_track(state_value)
__set_current_state(state_value)
-#define set_current_state_no_track(state_value)
set_current_state(state_value)
/*
* set_special_state() should be used for those states when the blocking task
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index bf969de8e2a03..604c1db913661 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1334,6 +1334,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
!rdp->rcu_iw_pending && rdp->rcu_iw_gpnum != rnp->gpnum &&
(rnp->ffmask & rdp->grpmask)) {
init_irq_work(&rdp->rcu_iw, rcu_iw_handler);
+ rdp->rcu_iw.flags = IRQ_WORK_HARD_IRQ;
rdp->rcu_iw_pending = true;
rdp->rcu_iw_gpnum = rnp->gpnum;
irq_work_queue_on(&rdp->rcu_iw, rdp->cpu);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 70641e8f3c898..6907657dd4b1d 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3545,10 +3545,15 @@ static inline void sched_submit_work(struct task_struct
*tsk)
/*
* If a worker went to sleep, notify and ask workqueue whether
* it wants to wake up a task to maintain concurrency.
+ * As this function is called inside the schedule() context,
+ * we disable preemption to avoid it calling schedule() again
+ * in the possible wakeup of a kworker.
*/
- if (tsk->flags & PF_WQ_WORKER)
+ if (tsk->flags & PF_WQ_WORKER) {
+ preempt_disable();
wq_worker_sleeping(tsk);
-
+ preempt_enable_no_resched();
+ }
if (tsk_is_pi_blocked(tsk))
return;
diff --git a/localversion-rt b/localversion-rt
index 05c35cb580779..6e44e540b927b 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt11
+-rt12
