v2.6.23-rc1-rt6-dw1

v2.6.23-rc1-rt6-dw1

[Daniel Walker]

I've released another version of the real-time tree. It's just a
slightly more bisectable tree, and it includes the fixes I've just
released.

You can download a combined patch from, 

ftp://source.mvista.com/pub/dwalker/rt/patch-2.6.23-rc1-rt6-dw1

Or a broken out set from,

ftp://source.mvista.com/pub/dwalker/rt/patch-2.6.23-rc1-rt6-dw1.tar.gz

Below I've included a per patch delta (as good as interdiff can make).
In the hopes that it will help integration. The changes are additions to
preempt-realtime-sched.patch which are extracted from patches later in
the series. This allow preempt-realtime-sched.patch to compile
standalone .. There was also a stray hunk in the version.patch which I
moved to another location. 

:: start series ::
--- tmp/patches/series	2007-07-26 14:47:21.000000000 -0700
+++ patches/series	2007-07-29 19:48:07.000000000 -0700
@@ -670,3 +670,12 @@
 schedule_on_each_cpu-enhance.patch
 schedule_on_each_cpu-enhance-rt.patch
 version.patch
+add-warn-on-rcu-read-unlock-imbalance.patch
+preempt-hardirqs-selects-preempt-softirqs.patch
+initialize-last_tick-in-calc_load.patch
+softirq-raise-wakeup-fix.patch
+preempt-realtime-net-mismerge.patch
+locking-cleanup.patch
+pickop-rt_lock_h.patch
+pickop-spinlock-rwlocks.patch
+pickop-seqlocks.patch
:: end series ::
:: start preempt-realtime-i386.patch ::
--- linux-2.6.22.orig/include/linux/smp.h	2007-07-27 00:20:49.000000000 +0000
+++ linux-2.6.22/include/linux/smp.h	2007-07-27 00:20:50.000000000 +0000
@@ -33,6 +33,16 @@ extern void smp_send_stop(void);
  */
 extern void smp_send_reschedule(int cpu);
 
+/*
+ * trigger a reschedule on all other CPUs:
+ */
+extern void smp_send_reschedule_allbutself(void);
+
+/*
+ * trigger a reschedule on all other CPUs:
+ */
+extern void smp_send_reschedule_allbutself(void);
+
 
 /*
  * Prepare machine for booting other CPUs.
@@ -97,6 +107,7 @@ static inline int up_smp_call_function(v
 		0;				\
 	})
 static inline void smp_send_reschedule(int cpu) { }
+static inline void smp_send_reschedule_allbutself(void) { }
 #define num_booting_cpus()			1
 #define smp_prepare_boot_cpu()			do {} while (0)
 #define smp_call_function_single(cpuid, func, info, retry, wait) \
:: end preempt-realtime-i386.patch ::
:: start preempt-realtime-sched.patch ::
--- linux-2.6.22.orig/include/linux/kernel.h
+++ linux-2.6.22/include/linux/kernel.h
@@ -88,7 +88,7 @@ extern int cond_resched(void);
 # define might_resched() do { } while (0)
 #endif
 
-#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
+#if defined(CONFIG_DEBUG_SPINLOCK_SLEEP) || defined(CONFIG_DEBUG_PREEMPT)
   void __might_sleep(char *file, int line);
 # define might_sleep() \
 	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
@@ -198,6 +198,7 @@ extern void add_taint(unsigned);
 /* Values used for system_state */
 extern enum system_states {
 	SYSTEM_BOOTING,
+	SYSTEM_BOOTING_SCHEDULER_OK,
 	SYSTEM_RUNNING,
 	SYSTEM_HALT,
 	SYSTEM_POWER_OFF,
--- linux-2.6.22.orig/init/main.c
+++ linux-2.6.22/init/main.c
@@ -438,6 +438,8 @@ static void noinline __init_refok rest_i
 {
 	int pid;
 
+	system_state = SYSTEM_BOOTING_SCHEDULER_OK;
+
 	kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
 	numa_default_policy();
 	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
--- linux-2.6.22.orig/lib/kernel_lock.c
+++ linux-2.6.22/lib/kernel_lock.c
@@ -35,22 +35,25 @@ DECLARE_MUTEX(kernel_sem);
  * about recursion, both due to the down() and due to the enabling of
  * preemption. schedule() will re-check the preemption flag after
  * reacquiring the semaphore.
+ *
+ * Called with interrupts disabled.
  */
 int __lockfunc __reacquire_kernel_lock(void)
 {
 	struct task_struct *task = current;
 	int saved_lock_depth = task->lock_depth;
 
+	local_irq_enable();
 	BUG_ON(saved_lock_depth < 0);
 
 	task->lock_depth = -1;
-	__preempt_enable_no_resched();
 
 	down(&kernel_sem);
 
-	preempt_disable();
 	task->lock_depth = saved_lock_depth;
 
+	local_irq_disable();
+
 	return 0;
 }
 
@@ -67,11 +70,15 @@ void __lockfunc lock_kernel(void)
 	struct task_struct *task = current;
 	int depth = task->lock_depth + 1;
 
-	if (likely(!depth))
+	if (likely(!depth)) {
 		/*
 		 * No recursion worries - we set up lock_depth _after_
 		 */
 		down(&kernel_sem);
+#ifdef CONFIG_DEBUG_RT_MUTEXES
+		current->last_kernel_lock = __builtin_return_address(0);
+#endif
+	}
 
 	task->lock_depth = depth;
 }
@@ -82,8 +89,12 @@ void __lockfunc unlock_kernel(void)
 
 	BUG_ON(task->lock_depth < 0);
 
-	if (likely(--task->lock_depth < 0))
+	if (likely(--task->lock_depth == -1)) {
+#ifdef CONFIG_DEBUG_RT_MUTEXES
+		current->last_kernel_lock = NULL;
+#endif
 		up(&kernel_sem);
+	}
 }
 
 #else
@@ -116,11 +127,9 @@ static  __cacheline_aligned_in_smp DEFIN
  */
 int __lockfunc __reacquire_kernel_lock(void)
 {
-	while (!_raw_spin_trylock(&kernel_flag)) {
-		if (test_thread_flag(TIF_NEED_RESCHED))
-			return -EAGAIN;
-		cpu_relax();
-	}
+	local_irq_enable();
+	_raw_spin_lock(&kernel_flag);
+	local_irq_disable();
 	preempt_disable();
 	return 0;
 }
:: end preempt-realtime-sched.patch ::
:: start preempt-realtime-core.patch ::
diff -u linux-rt-rebase.q/include/linux/kernel.h linux-2.6.22/include/linux/kernel.h
--- linux-rt-rebase.q/include/linux/kernel.h
+++ linux-2.6.22/include/linux/kernel.h	2007-07-27 01:32:15.000000000 +0000
@@ -88,7 +88,7 @@
 # define might_resched() do { } while (0)
 #endif
 
-#if defined(CONFIG_DEBUG_SPINLOCK_SLEEP) || defined(CONFIG_DEBUG_PREEMPT)
+#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
   void __might_sleep(char *file, int line);
 # define might_sleep() \
 	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
@@ -210,7 +210,6 @@
 /* Values used for system_state */
 extern enum system_states {
 	SYSTEM_BOOTING,
-	SYSTEM_BOOTING_SCHEDULER_OK,
 	SYSTEM_RUNNING,
 	SYSTEM_HALT,
 	SYSTEM_POWER_OFF,
reverted:
--- linux-rt-rebase.q/include/linux/smp.h
+++ linux-rt-rebase.q.orig/include/linux/smp.h
@@ -33,16 +33,6 @@
  */
 extern void smp_send_reschedule(int cpu);
 
-/*
- * trigger a reschedule on all other CPUs:
- */
-extern void smp_send_reschedule_allbutself(void);
-
-/*
- * trigger a reschedule on all other CPUs:
- */
-extern void smp_send_reschedule_allbutself(void);
-
 
 /*
  * Prepare machine for booting other CPUs.
@@ -107,7 +97,6 @@
 		0;				\
 	})
 static inline void smp_send_reschedule(int cpu) { }
-static inline void smp_send_reschedule_allbutself(void) { }
 #define num_booting_cpus()			1
 #define smp_prepare_boot_cpu()			do {} while (0)
 #define smp_call_function_single(cpuid, func, info, retry, wait) \
reverted:
--- linux-rt-rebase.q/lib/kernel_lock.c
+++ linux-rt-rebase.q.orig/lib/kernel_lock.c
@@ -35,25 +35,22 @@
  * about recursion, both due to the down() and due to the enabling of
  * preemption. schedule() will re-check the preemption flag after
  * reacquiring the semaphore.
- *
- * Called with interrupts disabled.
  */
 int __lockfunc __reacquire_kernel_lock(void)
 {
 	struct task_struct *task = current;
 	int saved_lock_depth = task->lock_depth;
 
-	local_irq_enable();
 	BUG_ON(saved_lock_depth < 0);
 
 	task->lock_depth = -1;
+	__preempt_enable_no_resched();
 
 	down(&kernel_sem);
 
+	preempt_disable();
 	task->lock_depth = saved_lock_depth;
 
-	local_irq_disable();
-
 	return 0;
 }
 
@@ -70,15 +67,11 @@
 	struct task_struct *task = current;
 	int depth = task->lock_depth + 1;
 
+	if (likely(!depth))
-	if (likely(!depth)) {
 		/*
 		 * No recursion worries - we set up lock_depth _after_
 		 */
 		down(&kernel_sem);
-#ifdef CONFIG_DEBUG_RT_MUTEXES
-		current->last_kernel_lock = __builtin_return_address(0);
-#endif
-	}
 
 	task->lock_depth = depth;
 }
@@ -89,12 +82,8 @@
 
 	BUG_ON(task->lock_depth < 0);
 
+	if (likely(--task->lock_depth < 0))
-	if (likely(--task->lock_depth == -1)) {
-#ifdef CONFIG_DEBUG_RT_MUTEXES
-		current->last_kernel_lock = NULL;
-#endif
 		up(&kernel_sem);
-	}
 }
 
 #else
@@ -127,9 +116,11 @@
  */
 int __lockfunc __reacquire_kernel_lock(void)
 {
+	while (!_raw_spin_trylock(&kernel_flag)) {
+		if (test_thread_flag(TIF_NEED_RESCHED))
+			return -EAGAIN;
+		cpu_relax();
+	}
-	local_irq_enable();
-	_raw_spin_lock(&kernel_flag);
-	local_irq_disable();
 	preempt_disable();
 	return 0;
 }
:: end preempt-realtime-core.patch ::
:: start preempt-realtime-init-show-enabled-debugs.patch ::
diff -u linux-rt-rebase.q/init/main.c linux-2.6.22/init/main.c
--- linux-rt-rebase.q/init/main.c
+++ linux-2.6.22/init/main.c	2007-07-27 01:22:46.000000000 +0000
@@ -438,8 +438,6 @@
 {
 	int pid;
 
-	system_state = SYSTEM_BOOTING_SCHEDULER_OK;
-
 	kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
 	numa_default_policy();
 	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
:: end preempt-realtime-init-show-enabled-debugs.patch ::
:: start schedule_on_each_cpu-enhance.patch ::
diff -u linux-rt-rebase.q/kernel/workqueue.c linux-2.6.22/kernel/workqueue.c
--- linux-rt-rebase.q/kernel/workqueue.c
+++ linux-2.6.22/kernel/workqueue.c	2007-07-29 00:41:17.000000000 +0000
@@ -647,6 +647,7 @@
 
 	return err;
 }
+EXPORT_SYMBOL(schedule_on_each_cpu);
 
 /**
  * schedule_on_each_cpu_wq - call a function on each online CPU on a per-CPU wq
:: end schedule_on_each_cpu-enhance.patch ::
:: start version.patch ::
reverted:
--- linux-rt-rebase.q/kernel/workqueue.c
+++ linux-rt-rebase.q.orig/kernel/workqueue.c
@@ -647,7 +647,6 @@
 
 	return err;
 }
-EXPORT_SYMBOL(schedule_on_each_cpu);
 
 /**
  * schedule_on_each_cpu_wq - call a function on each online CPU on a per-CPU wq
:: end version.patch ::

Re: v2.6.23-rc1-rt6-dw1

[Arjan van de Ven]

>  
> +/*
> + * trigger a reschedule on all other CPUs:
> + */
> +extern void smp_send_reschedule_allbutself(void);
> +
> +/*
> + * trigger a reschedule on all other CPUs:
> + */
> +extern void smp_send_reschedule_allbutself(void);
> +
>  
>  /*
>   * Prepare machine for booting other CPUs.
> @@ -97,6 +107,7 @@ static inline int up_smp_call_function(v
>  		0;				\
>  	})
>  static inline void smp_send_reschedule(int cpu) { }
> +static inline void smp_send_reschedule_allbutself(void) { }
>  #define num_booting_cpus()			1
>  #define smp_prepare_boot_cpu()			do {} while (0)
>  #define smp_call_function_single(cpuid, func, info, retry, wait) \
> :: end preempt-realtime-i386.patch ::
> :: start preempt-realtime-sched.patch ::
> --- linux-2.6.22.orig/include/linux/kernel.h
> +++ linux-2.6.22/include/linux/kernel.h
> @@ -88,7 +88,7 @@ extern int cond_resched(void);
>  # define might_resched() do { } while (0)
>  #endif
>  
> -#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
> +#if defined(CONFIG_DEBUG_SPINLOCK_SLEEP) || defined(CONFIG_DEBUG_PREEMPT)
>    void __might_sleep(char *file, int line);
>  # define might_sleep() \
>  	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
> @@ -198,6 +198,7 @@ extern void add_taint(unsigned);
>  /* Values used for system_state */
>  extern enum system_states {
>  	SYSTEM_BOOTING,
> +	SYSTEM_BOOTING_SCHEDULER_OK,
>  	SYSTEM_RUNNING,
>  	SYSTEM_HALT,
>  	SYSTEM_POWER_OFF,
> --- linux-2.6.22.orig/init/main.c
> +++ linux-2.6.22/init/main.c
> @@ -438,6 +438,8 @@ static void noinline __init_refok rest_i
>  {
>  	int pid;
>  
> +	system_state = SYSTEM_BOOTING_SCHEDULER_OK;
> +
>  	kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
>  	numa_default_policy();
>  	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
> --- linux-2.6.22.orig/lib/kernel_lock.c
> +++ linux-2.6.22/lib/kernel_lock.c
> @@ -35,22 +35,25 @@ DECLARE_MUTEX(kernel_sem);
>   * about recursion, both due to the down() and due to the enabling of
>   * preemption. schedule() will re-check the preemption flag after
>   * reacquiring the semaphore.
> + *
> + * Called with interrupts disabled.
>   */
>  int __lockfunc __reacquire_kernel_lock(void)
>  {
>  	struct task_struct *task = current;
>  	int saved_lock_depth = task->lock_depth;
>  
> +	local_irq_enable();
>  	BUG_ON(saved_lock_depth < 0);
>  
>  	task->lock_depth = -1;
> -	__preempt_enable_no_resched();
>  
>  	down(&kernel_sem);
>  
> -	preempt_disable();
>  	task->lock_depth = saved_lock_depth;
>  
> +	local_irq_disable();
> +
>  	return 0;
>  }
>  
> @@ -67,11 +70,15 @@ void __lockfunc lock_kernel(void)
>  	struct task_struct *task = current;
>  	int depth = task->lock_depth + 1;
>  
> -	if (likely(!depth))
> +	if (likely(!depth)) {
>  		/*
>  		 * No recursion worries - we set up lock_depth _after_
>  		 */
>  		down(&kernel_sem);
> +#ifdef CONFIG_DEBUG_RT_MUTEXES
> +		current->last_kernel_lock = __builtin_return_address(0);
> +#endif
> +	}
>  
>  	task->lock_depth = depth;
>  }
> @@ -82,8 +89,12 @@ void __lockfunc unlock_kernel(void)
>  
>  	BUG_ON(task->lock_depth < 0);
>  
> -	if (likely(--task->lock_depth < 0))
> +	if (likely(--task->lock_depth == -1)) {
> +#ifdef CONFIG_DEBUG_RT_MUTEXES
> +		current->last_kernel_lock = NULL;
> +#endif
>  		up(&kernel_sem);
> +	}
>  }
>  
>  #else
> @@ -116,11 +127,9 @@ static  __cacheline_aligned_in_smp DEFIN
>   */
>  int __lockfunc __reacquire_kernel_lock(void)
>  {
> -	while (!_raw_spin_trylock(&kernel_flag)) {
> -		if (test_thread_flag(TIF_NEED_RESCHED))
> -			return -EAGAIN;
> -		cpu_relax();
> -	}
> +	local_irq_enable();
> +	_raw_spin_lock(&kernel_flag);
> +	local_irq_disable();
>  	preempt_disable();
>  	return 0;
>  }
> :: end preempt-realtime-sched.patch ::
> :: start preempt-realtime-core.patch ::
> diff -u linux-rt-rebase.q/include/linux/kernel.h linux-2.6.22/include/linux/kernel.h
> --- linux-rt-rebase.q/include/linux/kernel.h
> +++ linux-2.6.22/include/linux/kernel.h	2007-07-27 01:32:15.000000000 +0000
> @@ -88,7 +88,7 @@
>  # define might_resched() do { } while (0)
>  #endif
>  
> -#if defined(CONFIG_DEBUG_SPINLOCK_SLEEP) || defined(CONFIG_DEBUG_PREEMPT)
> +#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
>    void __might_sleep(char *file, int line);
>  # define might_sleep() \
>  	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
> @@ -210,7 +210,6 @@
>  /* Values used for system_state */
>  extern enum system_states {
>  	SYSTEM_BOOTING,
> -	SYSTEM_BOOTING_SCHEDULER_OK,
>  	SYSTEM_RUNNING,
>  	SYSTEM_HALT,
>  	SYSTEM_POWER_OFF,
> reverted:
> --- linux-rt-rebase.q/include/linux/smp.h
> +++ linux-rt-rebase.q.orig/include/linux/smp.h
> @@ -33,16 +33,6 @@
>   */
>  extern void smp_send_reschedule(int cpu);
>  
> -/*
> - * trigger a reschedule on all other CPUs:
> - */
> -extern void smp_send_reschedule_allbutself(void);
> -
> -/*
> - * trigger a reschedule on all other CPUs:
> - */
> -extern void smp_send_reschedule_allbutself(void);
> -
>  
>  /*
>   * Prepare machine for booting other CPUs.
> @@ -107,7 +97,6 @@
>  		0;				\
>  	})
>  static inline void smp_send_reschedule(int cpu) { }
> -static inline void smp_send_reschedule_allbutself(void) { }
>  #define num_booting_cpus()			1
>  #define smp_prepare_boot_cpu()			do {} while (0)
>  #define smp_call_function_single(cpuid, func, info, retry, wait) \
> reverted:
> --- linux-rt-rebase.q/lib/kernel_lock.c
> +++ linux-rt-rebase.q.orig/lib/kernel_lock.c
> @@ -35,25 +35,22 @@
>   * about recursion, both due to the down() and due to the enabling of
>   * preemption. schedule() will re-check the preemption flag after
>   * reacquiring the semaphore.
> - *
> - * Called with interrupts disabled.
>   */
>  int __lockfunc __reacquire_kernel_lock(void)
>  {
>  	struct task_struct *task = current;
>  	int saved_lock_depth = task->lock_depth;
>  
> -	local_irq_enable();
>  	BUG_ON(saved_lock_depth < 0);
>  
>  	task->lock_depth = -1;
> +	__preempt_enable_no_resched();
>  
>  	down(&kernel_sem);
>  
> +	preempt_disable();
>  	task->lock_depth = saved_lock_depth;
>  
> -	local_irq_disable();
> -
>  	return 0;
>  }
>  
> @@ -70,15 +67,11 @@
>  	struct task_struct *task = current;
>  	int depth = task->lock_depth + 1;
>  
> +	if (likely(!depth))
> -	if (likely(!depth)) {
>  		/*
>  		 * No recursion worries - we set up lock_depth _after_
>  		 */
>  		down(&kernel_sem);
> -#ifdef CONFIG_DEBUG_RT_MUTEXES
> -		current->last_kernel_lock = __builtin_return_address(0);
> -#endif
> -	}
>  
>  	task->lock_depth = depth;
>  }
> @@ -89,12 +82,8 @@
>  
>  	BUG_ON(task->lock_depth < 0);
>  
> +	if (likely(--task->lock_depth < 0))
> -	if (likely(--task->lock_depth == -1)) {
> -#ifdef CONFIG_DEBUG_RT_MUTEXES
> -		current->last_kernel_lock = NULL;
> -#endif
>  		up(&kernel_sem);
> -	}
>  }
>  
>  #else
> @@ -127,9 +116,11 @@
>   */
>  int __lockfunc __reacquire_kernel_lock(void)
>  {
> +	while (!_raw_spin_trylock(&kernel_flag)) {
> +		if (test_thread_flag(TIF_NEED_RESCHED))
> +			return -EAGAIN;
> +		cpu_relax();
> +	}
> -	local_irq_enable();
> -	_raw_spin_lock(&kernel_flag);
> -	local_irq_disable();
>  	preempt_disable();
>  	return 0;
>  }
> :: end preempt-realtime-core.patch ::
> :: start preempt-realtime-init-show-enabled-debugs.patch ::
> diff -u linux-rt-rebase.q/init/main.c linux-2.6.22/init/main.c
> --- linux-rt-rebase.q/init/main.c
> +++ linux-2.6.22/init/main.c	2007-07-27 01:22:46.000000000 +0000
> @@ -438,8 +438,6 @@
>  {
>  	int pid;
>  
> -	system_state = SYSTEM_BOOTING_SCHEDULER_OK;
> -
>  	kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
>  	numa_default_policy();
>  	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
> :: end preempt-realtime-init-show-enabled-debugs.patch ::
> :: start schedule_on_each_cpu-enhance.patch ::
> diff -u linux-rt-rebase.q/kernel/workqueue.c linux-2.6.22/kernel/workqueue.c
> --- linux-rt-rebase.q/kernel/workqueue.c
> +++ linux-2.6.22/kernel/workqueue.c	2007-07-29 00:41:17.000000000 +0000
> @@ -647,6 +647,7 @@
>  
>  	return err;
>  }
> +EXPORT_SYMBOL(schedule_on_each_cpu);
>  
>  /**
>   * schedule_on_each_cpu_wq - call a function on each online CPU on a per-CPU wq
> :: end schedule_on_each_cpu-enhance.patch ::
> :: start version.patch ::
> reverted:
> --- linux-rt-rebase.q/kernel/workqueue.c
> +++ linux-rt-rebase.q.orig/kernel/workqueue.c
> @@ -647,7 +647,6 @@
>  
>  	return err;
>  }
> -EXPORT_SYMBOL(schedule_on_each_cpu);
>  
>  /**
>   * schedule_on_each_cpu_wq - call a function on each online CPU on a per-CPU wq
> :: end version.patch ::
> 
> 
> -
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-- 
if you want to mail me at work (you don't), use arjan (at) linux.intel.com
Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org

Re: v2.6.23-rc1-rt6-dw1

[Arjan van de Ven]

>  
> +/*
> + * trigger a reschedule on all other CPUs:
> + */
> +extern void smp_send_reschedule_allbutself(void);
> +
> +/*
> + * trigger a reschedule on all other CPUs:
> + */
> +extern void smp_send_reschedule_allbutself(void);
> +

just to make sure the C compiler doesn't forget it ?
or maybe the parser is suffering from memory lapse ? ;)

>  
> -#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
> +#if defined(CONFIG_DEBUG_SPINLOCK_SLEEP) || defined(CONFIG_DEBUG_PREEMPT)

why this change? the change is for spinlock debugging.. why add preempt
to this?


>    void __might_sleep(char *file, int line);
>  # define might_sleep() \
>  	do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
> @@ -198,6 +198,7 @@ extern void add_taint(unsigned);
>  /* Values used for system_state */
>  extern enum system_states {
>  	SYSTEM_BOOTING,
> +	SYSTEM_BOOTING_SCHEDULER_OK,

what is this used for? your patch doesn't add users of this...

>  	SYSTEM_RUNNING,
>  	SYSTEM_HALT,
>  	SYSTEM_POWER_OFF,
> --- linux-2.6.22.orig/init/main.c
> +++ linux-2.6.22/init/main.c
> @@ -438,6 +438,8 @@ static void noinline __init_refok rest_i
>  {
>  	int pid;
>  
> +	system_state = SYSTEM_BOOTING_SCHEDULER_OK;
> +
>  	kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
>  	numa_default_policy();
>  	pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
> --- linux-2.6.22.orig/lib/kernel_lock.c
> +++ linux-2.6.22/lib/kernel_lock.c
> @@ -35,22 +35,25 @@ DECLARE_MUTEX(kernel_sem);
>   * about recursion, both due to the down() and due to the enabling of
>   * preemption. schedule() will re-check the preemption flag after
>   * reacquiring the semaphore.
> + *
> + * Called with interrupts disabled.
>   */
>  int __lockfunc __reacquire_kernel_lock(void)
>  {
>  	struct task_struct *task = current;
>  	int saved_lock_depth = task->lock_depth;
>  
> +	local_irq_enable();

eh... if interrupts are off here that's a bad bug. Why work around it?

>  	BUG_ON(saved_lock_depth < 0);
>  
>  	task->lock_depth = -1;
> -	__preempt_enable_no_resched();
>  
>  	down(&kernel_sem);
>  
> -	preempt_disable();
>  	task->lock_depth = saved_lock_depth;
>  
> +	local_irq_disable();
> +

same here..

>  int __lockfunc __reacquire_kernel_lock(void)
>  {
> -	while (!_raw_spin_trylock(&kernel_flag)) {
> -		if (test_thread_flag(TIF_NEED_RESCHED))
> -			return -EAGAIN;
> -		cpu_relax();
> -	}
> +	local_irq_enable();
> +	_raw_spin_lock(&kernel_flag);
> +	local_irq_disable();

are you sure you want this semantics change?

Re: v2.6.23-rc1-rt6-dw1

[Daniel Walker]

On Sun, 2007-07-29 at 22:20 -0700, Arjan van de Ven wrote:
> >  
> > +/*
> > + * trigger a reschedule on all other CPUs:
> > + */
> > +extern void smp_send_reschedule_allbutself(void);
> > +
> > +/*
> > + * trigger a reschedule on all other CPUs:
> > + */
> > +extern void smp_send_reschedule_allbutself(void);
> > +
> 
> just to make sure the C compiler doesn't forget it ?
> or maybe the parser is suffering from memory lapse ? ;)

In terms of this whole patch, I should have been a little clearer about
it's meaning .. It represents code getting moved inside the -rt series..
For example the code above was originally in the,
preempt-realtime-core.patch and I moved it to the
preempt-realtime-i386.patch.

So I'm not actually adding any code.. I wasn't trying to put Ingo's code
up for evaluation either, since it's all still in development ..

Daniel