[PATCH 0/4] [ANNOUNCE] 3.0.65-rt92-rc1 stable review

[PATCH 0/4] [ANNOUNCE] 3.0.65-rt92-rc1 stable review

[Steven Rostedt]

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Dear RT Folks,

This is the RT stable review cycle of patch 3.0.65-rt92-rc1.

Please scream at me if I messed something up. Please test the patches too.

The -rc release will be uploaded to kernel.org and will be deleted when
the final release is out. This is just a review release (or release candidate).

The pre-releases will not be pushed to the git repository, only the
final release is.

If all goes well, this patch will be converted to the next main release
on 2/22/2013.

Enjoy,

-- Steve


To build 3.0.65-rt92-rc1 directly, the following patches should be applied:

  http://www.kernel.org/pub/linux/kernel/v3.0/linux-3.0.tar.xz

  http://www.kernel.org/pub/linux/kernel/v3.0/patch-3.0.65.xz

  http://www.kernel.org/pub/linux/kernel/projects/rt/3.0/patch-3.0.65-rt92-rc1.patch.xz

You can also build from 3.0.65-rt91 by applying the incremental patch:

http://www.kernel.org/pub/linux/kernel/projects/rt/3.0/incr/patch-3.0.65-rt91-rt92-rc1.patch.xz


Changes from 3.0.65-rt91:

---


Steven Rostedt (2):
      acpi/rt: Convert acpi_gbl_hardware lock back to a raw_spinlock_t
      Linux 3.0.65-rt92-rc1

Thomas Gleixner (2):
      x86/32: Use kmap switch for non highmem as well
      rcutiny: Use simple waitqueue

----
 arch/x86/kernel/process_32.c    |    2 +-
 drivers/acpi/acpica/acglobal.h  |    2 +-
 drivers/acpi/acpica/hwregs.c    |    4 ++--
 drivers/acpi/acpica/hwxface.c   |    4 ++--
 drivers/acpi/acpica/utmutex.c   |    4 ++--
 include/acpi/platform/aclinux.h |   14 ++++++++++++++
 include/linux/sched.h           |    4 +++-
 kernel/rcutiny_plugin.h         |    9 +++++----
 localversion-rt                 |    2 +-
 9 files changed, 31 insertions(+), 14 deletions(-)

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[PATCH 1/4] x86/32: Use kmap switch for non highmem as well

[Steven Rostedt]

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From: Thomas Gleixner <tglx@linutronix.de>

Even with CONFIG_HIGHMEM=n we need to take care of the "atomic"
mappings which are installed via iomap_atomic.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable-rt@vger.kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 arch/x86/kernel/process_32.c |    2 +-
 include/linux/sched.h        |    4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 95f2630..4a0d37f 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -336,7 +336,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 		     task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT))
 		__switch_to_xtra(prev_p, next_p, tss);
 
-#if defined CONFIG_PREEMPT_RT_FULL && defined CONFIG_HIGHMEM
+#ifdef CONFIG_PREEMPT_RT_FULL
 	/*
 	 * Save @prev's kmap_atomic stack
 	 */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8772834..285ab45 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1602,9 +1602,11 @@ struct task_struct {
 	struct rcu_head put_rcu;
 	int softirq_nestcnt;
 #endif
-#if defined CONFIG_PREEMPT_RT_FULL && defined CONFIG_HIGHMEM
+#ifdef CONFIG_PREEMPT_RT_FULL
+# if defined CONFIG_HIGHMEM || defined CONFIG_X86_32
 	int kmap_idx;
 	pte_t kmap_pte[KM_TYPE_NR];
+# endif
 #endif
 
 #ifdef CONFIG_DEBUG_PREEMPT
-- 
1.7.10.4



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[PATCH 2/4] acpi/rt: Convert acpi_gbl_hardware lock back to a raw_spinlock_t

[Steven Rostedt]

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From: Steven Rostedt <rostedt@goodmis.org>

We hit the following bug with 3.6-rt:

[    5.898990] BUG: scheduling while atomic: swapper/3/0/0x00000002
[    5.898991] no locks held by swapper/3/0.
[    5.898993] Modules linked in:
[    5.898996] Pid: 0, comm: swapper/3 Not tainted 3.6.11-rt28.19.el6rt.x86_64.debug #1
[    5.898997] Call Trace:
[    5.899011]  [<ffffffff810804e7>] __schedule_bug+0x67/0x90
[    5.899028]  [<ffffffff81577923>] __schedule+0x793/0x7a0
[    5.899032]  [<ffffffff810b4e40>] ? debug_rt_mutex_print_deadlock+0x50/0x200
[    5.899034]  [<ffffffff81577b89>] schedule+0x29/0x70
[    5.899036] BUG: scheduling while atomic: swapper/7/0/0x00000002
[    5.899037] no locks held by swapper/7/0.
[    5.899039]  [<ffffffff81578525>] rt_spin_lock_slowlock+0xe5/0x2f0
[    5.899040] Modules linked in:
[    5.899041]
[    5.899045]  [<ffffffff81579a58>] ? _raw_spin_unlock_irqrestore+0x38/0x90
[    5.899046] Pid: 0, comm: swapper/7 Not tainted 3.6.11-rt28.19.el6rt.x86_64.debug #1
[    5.899047] Call Trace:
[    5.899049]  [<ffffffff81578bc6>] rt_spin_lock+0x16/0x40
[    5.899052]  [<ffffffff810804e7>] __schedule_bug+0x67/0x90
[    5.899054]  [<ffffffff8157d3f0>] ? notifier_call_chain+0x80/0x80
[    5.899056]  [<ffffffff81577923>] __schedule+0x793/0x7a0
[    5.899059]  [<ffffffff812f2034>] acpi_os_acquire_lock+0x1f/0x23
[    5.899062]  [<ffffffff810b4e40>] ? debug_rt_mutex_print_deadlock+0x50/0x200
[    5.899068]  [<ffffffff8130be64>] acpi_write_bit_register+0x33/0xb0
[    5.899071]  [<ffffffff81577b89>] schedule+0x29/0x70
[    5.899072]  [<ffffffff8130be13>] ? acpi_read_bit_register+0x33/0x51
[    5.899074]  [<ffffffff81578525>] rt_spin_lock_slowlock+0xe5/0x2f0
[    5.899077]  [<ffffffff8131d1fc>] acpi_idle_enter_bm+0x8a/0x28e
[    5.899079]  [<ffffffff81579a58>] ? _raw_spin_unlock_irqrestore+0x38/0x90
[    5.899081]  [<ffffffff8107e5da>] ? this_cpu_load+0x1a/0x30
[    5.899083]  [<ffffffff81578bc6>] rt_spin_lock+0x16/0x40
[    5.899087]  [<ffffffff8144c759>] cpuidle_enter+0x19/0x20
[    5.899088]  [<ffffffff8157d3f0>] ? notifier_call_chain+0x80/0x80
[    5.899090]  [<ffffffff8144c777>] cpuidle_enter_state+0x17/0x50
[    5.899092]  [<ffffffff812f2034>] acpi_os_acquire_lock+0x1f/0x23
[    5.899094]  [<ffffffff8144d1a1>] cpuidle899101]  [<ffffffff8130be13>] ?

As the acpi code disables interrupts in acpi_idle_enter_bm, and calls
code that grabs the acpi lock, it causes issues as the lock is currently
in RT a sleeping lock.

The lock was converted from a raw to a sleeping lock due to some
previous issues, and tests that showed it didn't seem to matter.
Unfortunately, it did matter for one of our boxes.

This patch converts the lock back to a raw lock. I've run this code on a
few of my own machines, one being my laptop that uses the acpi quite
extensively. I've been able to suspend and resume without issues.

[ tglx: Made the change exclusive for acpi_gbl_hardware_lock ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: John Kacur <jkacur@gmail.com>
Cc: Clark Williams <clark@redhat.com>
Link: http://lkml.kernel.org/r/1360765565.23152.5.camel@gandalf.local.home
Cc: stable-rt@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/acpi/acpica/acglobal.h  |    2 +-
 drivers/acpi/acpica/hwregs.c    |    4 ++--
 drivers/acpi/acpica/hwxface.c   |    4 ++--
 drivers/acpi/acpica/utmutex.c   |    4 ++--
 include/acpi/platform/aclinux.h |   14 ++++++++++++++
 5 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
index 73863d8..3d208c8 100644
--- a/drivers/acpi/acpica/acglobal.h
+++ b/drivers/acpi/acpica/acglobal.h
@@ -230,7 +230,7 @@ ACPI_EXTERN u8 acpi_gbl_global_lock_pending;
  * interrupt level
  */
 ACPI_EXTERN acpi_spinlock acpi_gbl_gpe_lock;	/* For GPE data structs and registers */
-ACPI_EXTERN acpi_spinlock acpi_gbl_hardware_lock;	/* For ACPI H/W except GPE registers */
+ACPI_EXTERN acpi_raw_spinlock acpi_gbl_hardware_lock;	/* For ACPI H/W except GPE registers */
 
 /*****************************************************************************
  *
diff --git a/drivers/acpi/acpica/hwregs.c b/drivers/acpi/acpica/hwregs.c
index 55accb7..1da9213 100644
--- a/drivers/acpi/acpica/hwregs.c
+++ b/drivers/acpi/acpica/hwregs.c
@@ -263,7 +263,7 @@ acpi_status acpi_hw_clear_acpi_status(void)
 			  ACPI_BITMASK_ALL_FIXED_STATUS,
 			  ACPI_FORMAT_UINT64(acpi_gbl_xpm1a_status.address)));
 
-	lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
+	raw_spin_lock_irqsave(acpi_gbl_hardware_lock, lock_flags);
 
 	/* Clear the fixed events in PM1 A/B */
 
@@ -278,7 +278,7 @@ acpi_status acpi_hw_clear_acpi_status(void)
 	status = acpi_ev_walk_gpe_list(acpi_hw_clear_gpe_block, NULL);
 
       unlock_and_exit:
-	acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
+	raw_spin_unlock_irqrestore(acpi_gbl_hardware_lock, lock_flags);
 	return_ACPI_STATUS(status);
 }
 
diff --git a/drivers/acpi/acpica/hwxface.c b/drivers/acpi/acpica/hwxface.c
index f75f81a..94a33ce 100644
--- a/drivers/acpi/acpica/hwxface.c
+++ b/drivers/acpi/acpica/hwxface.c
@@ -386,7 +386,7 @@ acpi_status acpi_write_bit_register(u32 register_id, u32 value)
 		return_ACPI_STATUS(AE_BAD_PARAMETER);
 	}
 
-	lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
+	raw_spin_lock_irqsave(acpi_gbl_hardware_lock, lock_flags);
 
 	/*
 	 * At this point, we know that the parent register is one of the
@@ -447,7 +447,7 @@ acpi_status acpi_write_bit_register(u32 register_id, u32 value)
 
 unlock_and_exit:
 
-	acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
+	raw_spin_unlock_irqrestore(acpi_gbl_hardware_lock, lock_flags);
 	return_ACPI_STATUS(status);
 }
 
diff --git a/drivers/acpi/acpica/utmutex.c b/drivers/acpi/acpica/utmutex.c
index 7d797e2..b611bf3 100644
--- a/drivers/acpi/acpica/utmutex.c
+++ b/drivers/acpi/acpica/utmutex.c
@@ -88,7 +88,7 @@ acpi_status acpi_ut_mutex_initialize(void)
 		return_ACPI_STATUS (status);
 	}
 
-	status = acpi_os_create_lock (&acpi_gbl_hardware_lock);
+	status = acpi_os_create_raw_lock (&acpi_gbl_hardware_lock);
 	if (ACPI_FAILURE (status)) {
 		return_ACPI_STATUS (status);
 	}
@@ -135,7 +135,7 @@ void acpi_ut_mutex_terminate(void)
 	/* Delete the spinlocks */
 
 	acpi_os_delete_lock(acpi_gbl_gpe_lock);
-	acpi_os_delete_lock(acpi_gbl_hardware_lock);
+	acpi_os_delete_raw_lock(acpi_gbl_hardware_lock);
 
 	/* Delete the reader/writer lock */
 
diff --git a/include/acpi/platform/aclinux.h b/include/acpi/platform/aclinux.h
index 2ce1be9..17d24de 100644
--- a/include/acpi/platform/aclinux.h
+++ b/include/acpi/platform/aclinux.h
@@ -74,6 +74,7 @@
 
 #define acpi_cache_t                        struct kmem_cache
 #define acpi_spinlock                       spinlock_t *
+#define acpi_raw_spinlock                   raw_spinlock_t *
 #define acpi_cpu_flags                      unsigned long
 
 #else /* !__KERNEL__ */
@@ -177,6 +178,19 @@ static inline void *acpi_os_acquire_object(acpi_cache_t * cache)
 	lock ? AE_OK : AE_NO_MEMORY;				\
 })
 
+#define acpi_os_create_raw_lock(__handle)			\
+({								\
+	raw_spinlock_t *lock = ACPI_ALLOCATE(sizeof(*lock));	\
+								\
+	if (lock) {						\
+		*(__handle) = lock;				\
+		raw_spin_lock_init(*(__handle));		\
+	}							\
+	lock ? AE_OK : AE_NO_MEMORY;				\
+})
+
+#define acpi_os_delete_raw_lock(__handle)	kfree(__handle)
+
 #endif /* __KERNEL__ */
 
 #endif /* __ACLINUX_H__ */
-- 
1.7.10.4



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[PATCH 3/4] rcutiny: Use simple waitqueue

[Steven Rostedt]

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From: Thomas Gleixner <tglx@linutronix.de>

Simple waitqueues can be handled from interrupt disabled contexts.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/rcutiny_plugin.h |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/kernel/rcutiny_plugin.h b/kernel/rcutiny_plugin.h
index f259c67..1cd0c6e 100644
--- a/kernel/rcutiny_plugin.h
+++ b/kernel/rcutiny_plugin.h
@@ -25,6 +25,7 @@
 #include <linux/kthread.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
+#include <linux/wait-simple.h>
 
 #ifdef CONFIG_RCU_TRACE
 #define RCU_TRACE(stmt)	stmt
@@ -736,7 +737,7 @@ void synchronize_rcu(void)
 }
 EXPORT_SYMBOL_GPL(synchronize_rcu);
 
-static DECLARE_WAIT_QUEUE_HEAD(sync_rcu_preempt_exp_wq);
+static DEFINE_SWAIT_HEAD(sync_rcu_preempt_exp_wq);
 static unsigned long sync_rcu_preempt_exp_count;
 static DEFINE_MUTEX(sync_rcu_preempt_exp_mutex);
 
@@ -758,7 +759,7 @@ static int rcu_preempted_readers_exp(void)
  */
 static void rcu_report_exp_done(void)
 {
-	wake_up(&sync_rcu_preempt_exp_wq);
+	swait_wake(&sync_rcu_preempt_exp_wq);
 }
 
 /*
@@ -810,8 +811,8 @@ void synchronize_rcu_expedited(void)
 	else {
 		rcu_initiate_boost();
 		local_irq_restore(flags);
-		wait_event(sync_rcu_preempt_exp_wq,
-			   !rcu_preempted_readers_exp());
+		swait_event(sync_rcu_preempt_exp_wq,
+			    !rcu_preempted_readers_exp());
 	}
 
 	/* Clean up and exit. */
-- 
1.7.10.4



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[PATCH 4/4] Linux 3.0.65-rt92-rc1

[Steven Rostedt]

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From: Steven Rostedt <srostedt@redhat.com>

---
 localversion-rt |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/localversion-rt b/localversion-rt
index e95e338..dc0be96 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt91
+-rt92-rc1
-- 
1.7.10.4



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Re: [PATCH 0/4] [ANNOUNCE] 3.0.65-rt92-rc1 stable review

[Steven Rostedt]

Oops! I used the wrong script to send. It used my "Ingo Pull" script
instead of my "stable RT review". Subject is missing "[PATCH RT]" and it
went to the wrong people.

Sorry for the noise, I'm in a hurry to get finished packing for ELC.

-- Steve


On Tue, 2013-02-19 at 00:30 -0500, Steven Rostedt wrote:
> Dear RT Folks,
> 
> This is the RT stable review cycle of patch 3.0.65-rt92-rc1.
> 
> Please scream at me if I messed something up. Please test the patches too.
> 
> The -rc release will be uploaded to kernel.org and will be deleted when
> the final release is out. This is just a review release (or release candidate).
> 
> The pre-releases will not be pushed to the git repository, only the
> final release is.
> 
> If all goes well, this patch will be converted to the next main release
> on 2/22/2013.
> 
> Enjoy,