Merge branches 'core/debugobjects', 'core/iommu', 'core/locking',...

Merge branches 'core/debugobjects', 'core/iommu', 'core/locking', 'core/printk', 'core/rcu', 'core/resources', 'core/softirq' and 'core/stacktrace' into core/core

Documentation/RCU/00-INDEX

@@ -16,6 +16,8 @@ RTFP.txt
 	- List of RCU papers (bibliography) going back to 1980.
 torture.txt
 	- RCU Torture Test Operation (CONFIG_RCU_TORTURE_TEST)
+trace.txt
+	- CONFIG_RCU_TRACE debugfs files and formats
 UP.txt
 	- RCU on Uniprocessor Systems
 whatisRCU.txt

arch/powerpc/platforms/pseries/rtasd.c

@@ -208,6 +208,7 @@ void pSeries_log_error(char *buf, unsigned int err_type, int fatal)
 		break;
 	case ERR_TYPE_KERNEL_PANIC:
 	default:
+		WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
 		spin_unlock_irqrestore(&rtasd_log_lock, s);
 		return;
 	}
@@ -227,6 +228,7 @@ void pSeries_log_error(char *buf, unsigned int err_type, int fatal)
 	/* Check to see if we need to or have stopped logging */
 	if (fatal || !logging_enabled) {
 		logging_enabled = 0;
+		WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
 		spin_unlock_irqrestore(&rtasd_log_lock, s);
 		return;
 	}
@@ -249,11 +251,13 @@ void pSeries_log_error(char *buf, unsigned int err_type, int fatal)
 		else
 			rtas_log_start += 1;
 
+		WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
 		spin_unlock_irqrestore(&rtasd_log_lock, s);
 		wake_up_interruptible(&rtas_log_wait);
 		break;
 	case ERR_TYPE_KERNEL_PANIC:
 	default:
+		WARN_ON_ONCE(!irqs_disabled()); /* @@@ DEBUG @@@ */
 		spin_unlock_irqrestore(&rtasd_log_lock, s);
 		return;
 	}

arch/x86/include/asm/dma-mapping.h

@@ -65,7 +65,7 @@ static inline struct dma_mapping_ops *get_dma_ops(struct device *dev)
 		return dma_ops;
 	else
 		return dev->archdata.dma_ops;
-#endif /* _ASM_X86_DMA_MAPPING_H */
+#endif
 }
 
 /* Make sure we keep the same behaviour */

arch/x86/include/asm/iommu.h

@@ -7,8 +7,6 @@ extern struct dma_mapping_ops nommu_dma_ops;
 extern int force_iommu, no_iommu;
 extern int iommu_detected;
 
-extern unsigned long iommu_nr_pages(unsigned long addr, unsigned long len);
-
 /* 10 seconds */
 #define DMAR_OPERATION_TIMEOUT ((cycles_t) tsc_khz*10*1000)
 

arch/x86/include/asm/pci.h

@@ -82,6 +82,8 @@ static inline void pci_dma_burst_advice(struct pci_dev *pdev,
 static inline void early_quirks(void) { }
 #endif
 
+extern void pci_iommu_alloc(void);
+
 #endif  /* __KERNEL__ */
 
 #ifdef CONFIG_X86_32

arch/x86/include/asm/pci_64.h

@@ -23,7 +23,6 @@ extern int (*pci_config_write)(int seg, int bus, int dev, int fn,
 			       int reg, int len, u32 value);
 
 extern void dma32_reserve_bootmem(void);
-extern void pci_iommu_alloc(void);
 
 /* The PCI address space does equal the physical memory
  * address space.  The networking and block device layers use

arch/x86/kernel/Makefile

@@ -105,6 +105,8 @@ microcode-$(CONFIG_MICROCODE_INTEL)	+= microcode_intel.o
 microcode-$(CONFIG_MICROCODE_AMD)	+= microcode_amd.o
 obj-$(CONFIG_MICROCODE)			+= microcode.o
 
+obj-$(CONFIG_SWIOTLB)			+= pci-swiotlb_64.o # NB rename without _64
+
 ###
 # 64 bit specific files
 ifeq ($(CONFIG_X86_64),y)
@@ -118,7 +120,6 @@ ifeq ($(CONFIG_X86_64),y)
         obj-$(CONFIG_GART_IOMMU)	+= pci-gart_64.o aperture_64.o
         obj-$(CONFIG_CALGARY_IOMMU)	+= pci-calgary_64.o tce_64.o
         obj-$(CONFIG_AMD_IOMMU)		+= amd_iommu_init.o amd_iommu.o
-        obj-$(CONFIG_SWIOTLB)		+= pci-swiotlb_64.o
 
         obj-$(CONFIG_PCI_MMCONFIG)	+= mmconf-fam10h_64.o
 endif

arch/x86/kernel/pci-dma.c

@@ -105,11 +105,15 @@ static void __init dma32_free_bootmem(void)
 	dma32_bootmem_ptr = NULL;
 	dma32_bootmem_size = 0;
 }
+#endif
 
 void __init pci_iommu_alloc(void)
 {
+#ifdef CONFIG_X86_64
 	/* free the range so iommu could get some range less than 4G */
 	dma32_free_bootmem();
+#endif
+
 	/*
 	 * The order of these functions is important for
 	 * fall-back/fail-over reasons
@@ -125,15 +129,6 @@ void __init pci_iommu_alloc(void)
 	pci_swiotlb_init();
 }
 
-unsigned long iommu_nr_pages(unsigned long addr, unsigned long len)
-{
-	unsigned long size = roundup((addr & ~PAGE_MASK) + len, PAGE_SIZE);
-
-	return size >> PAGE_SHIFT;
-}
-EXPORT_SYMBOL(iommu_nr_pages);
-#endif
-
 void *dma_generic_alloc_coherent(struct device *dev, size_t size,
 				 dma_addr_t *dma_addr, gfp_t flag)
 {

arch/x86/kernel/pci-swiotlb_64.c

@@ -3,6 +3,8 @@
 #include <linux/pci.h>
 #include <linux/cache.h>
 #include <linux/module.h>
+#include <linux/swiotlb.h>
+#include <linux/bootmem.h>
 #include <linux/dma-mapping.h>
 
 #include <asm/iommu.h>
@@ -11,6 +13,31 @@
 
 int swiotlb __read_mostly;
 
+void *swiotlb_alloc_boot(size_t size, unsigned long nslabs)
+{
+	return alloc_bootmem_low_pages(size);
+}
+
+void *swiotlb_alloc(unsigned order, unsigned long nslabs)
+{
+	return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
+}
+
+dma_addr_t swiotlb_phys_to_bus(phys_addr_t paddr)
+{
+	return paddr;
+}
+
+phys_addr_t swiotlb_bus_to_phys(dma_addr_t baddr)
+{
+	return baddr;
+}
+
+int __weak swiotlb_arch_range_needs_mapping(void *ptr, size_t size)
+{
+	return 0;
+}
+
 static dma_addr_t
 swiotlb_map_single_phys(struct device *hwdev, phys_addr_t paddr, size_t size,
 			int direction)
@@ -50,8 +77,10 @@ struct dma_mapping_ops swiotlb_dma_ops = {
 void __init pci_swiotlb_init(void)
 {
 	/* don't initialize swiotlb if iommu=off (no_iommu=1) */
+#ifdef CONFIG_X86_64
 	if (!iommu_detected && !no_iommu && max_pfn > MAX_DMA32_PFN)
 	       swiotlb = 1;
+#endif
 	if (swiotlb_force)
 		swiotlb = 1;
 	if (swiotlb) {

arch/x86/mm/init_32.c

@@ -21,6 +21,7 @@
 #include <linux/init.h>
 #include <linux/highmem.h>
 #include <linux/pagemap.h>
+#include <linux/pci.h>
 #include <linux/pfn.h>
 #include <linux/poison.h>
 #include <linux/bootmem.h>
@@ -971,6 +972,8 @@ void __init mem_init(void)
 
 	start_periodic_check_for_corruption();
 
+	pci_iommu_alloc();
+
 #ifdef CONFIG_FLATMEM
 	BUG_ON(!mem_map);
 #endif

include/linux/bottom_half.h

@@ -2,7 +2,6 @@
 #define _LINUX_BH_H
 
 extern void local_bh_disable(void);
-extern void __local_bh_enable(void);
 extern void _local_bh_enable(void);
 extern void local_bh_enable(void);
 extern void local_bh_enable_ip(unsigned long ip);

include/linux/hardirq.h

@@ -118,13 +118,17 @@ static inline void account_system_vtime(struct task_struct *tsk)
 }
 #endif
 
-#if defined(CONFIG_PREEMPT_RCU) && defined(CONFIG_NO_HZ)
+#if defined(CONFIG_NO_HZ) && !defined(CONFIG_CLASSIC_RCU)
 extern void rcu_irq_enter(void);
 extern void rcu_irq_exit(void);
+extern void rcu_nmi_enter(void);
+extern void rcu_nmi_exit(void);
 #else
 # define rcu_irq_enter() do { } while (0)
 # define rcu_irq_exit() do { } while (0)
-#endif /* CONFIG_PREEMPT_RCU */
+# define rcu_nmi_enter() do { } while (0)
+# define rcu_nmi_exit() do { } while (0)
+#endif /* #if defined(CONFIG_NO_HZ) && !defined(CONFIG_CLASSIC_RCU) */
 
 /*
  * It is safe to do non-atomic ops on ->hardirq_context,
@@ -134,7 +138,6 @@ extern void rcu_irq_exit(void);
  */
 #define __irq_enter()					\
 	do {						\
-		rcu_irq_enter();			\
 		account_system_vtime(current);		\
 		add_preempt_count(HARDIRQ_OFFSET);	\
 		trace_hardirq_enter();			\
@@ -153,7 +156,6 @@ extern void irq_enter(void);
 		trace_hardirq_exit();			\
 		account_system_vtime(current);		\
 		sub_preempt_count(HARDIRQ_OFFSET);	\
-		rcu_irq_exit();				\
 	} while (0)
 
 /*
@@ -161,7 +163,7 @@ extern void irq_enter(void);
  */
 extern void irq_exit(void);
 
-#define nmi_enter()		do { lockdep_off(); __irq_enter(); } while (0)
-#define nmi_exit()		do { __irq_exit(); lockdep_on(); } while (0)
+#define nmi_enter()		do { lockdep_off(); rcu_nmi_enter(); __irq_enter(); } while (0)
+#define nmi_exit()		do { __irq_exit(); rcu_nmi_exit(); lockdep_on(); } while (0)
 
 #endif /* LINUX_HARDIRQ_H */

include/linux/lockdep.h

@@ -314,9 +314,16 @@ extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 extern void lock_release(struct lockdep_map *lock, int nested,
 			 unsigned long ip);
 
-extern void lock_set_subclass(struct lockdep_map *lock, unsigned int subclass,
+extern void lock_set_class(struct lockdep_map *lock, const char *name,
+			   struct lock_class_key *key, unsigned int subclass,
 			   unsigned long ip);
 
+static inline void lock_set_subclass(struct lockdep_map *lock,
+		unsigned int subclass, unsigned long ip)
+{
+	lock_set_class(lock, lock->name, lock->key, subclass, ip);
+}
+
 # define INIT_LOCKDEP				.lockdep_recursion = 0,
 
 #define lockdep_depth(tsk)	(debug_locks ? (tsk)->lockdep_depth : 0)
@@ -333,6 +340,7 @@ static inline void lockdep_on(void)
 
 # define lock_acquire(l, s, t, r, c, n, i)	do { } while (0)
 # define lock_release(l, n, i)			do { } while (0)
+# define lock_set_class(l, n, k, s, i)		do { } while (0)
 # define lock_set_subclass(l, s, i)		do { } while (0)
 # define lockdep_init()				do { } while (0)
 # define lockdep_info()				do { } while (0)

include/linux/rcupdate.h

@@ -52,11 +52,15 @@ struct rcu_head {
 	void (*func)(struct rcu_head *head);
 };
 
-#ifdef CONFIG_CLASSIC_RCU
+#if defined(CONFIG_CLASSIC_RCU)
 #include <linux/rcuclassic.h>
-#else /* #ifdef CONFIG_CLASSIC_RCU */
+#elif defined(CONFIG_TREE_RCU)
+#include <linux/rcutree.h>
+#elif defined(CONFIG_PREEMPT_RCU)
 #include <linux/rcupreempt.h>
-#endif /* #else #ifdef CONFIG_CLASSIC_RCU */
+#else
+#error "Unknown RCU implementation specified to kernel configuration"
+#endif /* #else #if defined(CONFIG_CLASSIC_RCU) */
 
 #define RCU_HEAD_INIT 	{ .next = NULL, .func = NULL }
 #define RCU_HEAD(head) struct rcu_head head = RCU_HEAD_INIT

include/linux/swiotlb.h

@@ -7,9 +7,31 @@ struct device;
 struct dma_attrs;
 struct scatterlist;
 
+/*
+ * Maximum allowable number of contiguous slabs to map,
+ * must be a power of 2.  What is the appropriate value ?
+ * The complexity of {map,unmap}_single is linearly dependent on this value.
+ */
+#define IO_TLB_SEGSIZE	128
+
+
+/*
+ * log of the size of each IO TLB slab.  The number of slabs is command line
+ * controllable.
+ */
+#define IO_TLB_SHIFT 11
+
 extern void
 swiotlb_init(void);
 
+extern void *swiotlb_alloc_boot(size_t bytes, unsigned long nslabs);
+extern void *swiotlb_alloc(unsigned order, unsigned long nslabs);
+
+extern dma_addr_t swiotlb_phys_to_bus(phys_addr_t address);
+extern phys_addr_t swiotlb_bus_to_phys(dma_addr_t address);
+
+extern int swiotlb_arch_range_needs_mapping(void *ptr, size_t size);
+
 extern void
 *swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 			dma_addr_t *dma_handle, gfp_t flags);

init/Kconfig

@@ -928,10 +928,90 @@ source "block/Kconfig"
 config PREEMPT_NOTIFIERS
 	bool
 
+choice
+	prompt "RCU Implementation"
+	default CLASSIC_RCU
+
 config CLASSIC_RCU
-	def_bool !PREEMPT_RCU
+	bool "Classic RCU"
 	help
 	  This option selects the classic RCU implementation that is
 	  designed for best read-side performance on non-realtime
-	  systems.  Classic RCU is the default.  Note that the
-	  PREEMPT_RCU symbol is used to select/deselect this option.
+	  systems.
+
+	  Select this option if you are unsure.
+
+config TREE_RCU
+	bool "Tree-based hierarchical RCU"
+	help
+	  This option selects the RCU implementation that is
+	  designed for very large SMP system with hundreds or
+	  thousands of CPUs.
+
+config PREEMPT_RCU
+	bool "Preemptible RCU"
+	depends on PREEMPT
+	help
+	  This option reduces the latency of the kernel by making certain
+	  RCU sections preemptible. Normally RCU code is non-preemptible, if
+	  this option is selected then read-only RCU sections become
+	  preemptible. This helps latency, but may expose bugs due to
+	  now-naive assumptions about each RCU read-side critical section
+	  remaining on a given CPU through its execution.
+
+endchoice
+
+config RCU_TRACE
+	bool "Enable tracing for RCU"
+	depends on TREE_RCU || PREEMPT_RCU
+	help
+	  This option provides tracing in RCU which presents stats
+	  in debugfs for debugging RCU implementation.
+
+	  Say Y here if you want to enable RCU tracing
+	  Say N if you are unsure.
+
+config RCU_FANOUT
+	int "Tree-based hierarchical RCU fanout value"
+	range 2 64 if 64BIT
+	range 2 32 if !64BIT
+	depends on TREE_RCU
+	default 64 if 64BIT
+	default 32 if !64BIT
+	help
+	  This option controls the fanout of hierarchical implementations
+	  of RCU, allowing RCU to work efficiently on machines with
+	  large numbers of CPUs.  This value must be at least the cube
+	  root of NR_CPUS, which allows NR_CPUS up to 32,768 for 32-bit
+	  systems and up to 262,144 for 64-bit systems.
+
+	  Select a specific number if testing RCU itself.
+	  Take the default if unsure.
+
+config RCU_FANOUT_EXACT
+	bool "Disable tree-based hierarchical RCU auto-balancing"
+	depends on TREE_RCU
+	default n
+	help
+	  This option forces use of the exact RCU_FANOUT value specified,
+	  regardless of imbalances in the hierarchy.  This is useful for
+	  testing RCU itself, and might one day be useful on systems with
+	  strong NUMA behavior.
+
+	  Without RCU_FANOUT_EXACT, the code will balance the hierarchy.
+
+	  Say N if unsure.
+
+config TREE_RCU_TRACE
+	def_bool RCU_TRACE && TREE_RCU
+	select DEBUG_FS
+	help
+	  This option provides tracing for the TREE_RCU implementation,
+	  permitting Makefile to trivially select kernel/rcutree_trace.c.
+
+config PREEMPT_RCU_TRACE
+	def_bool RCU_TRACE && PREEMPT_RCU
+	select DEBUG_FS
+	help
+	  This option provides tracing for the PREEMPT_RCU implementation,
+	  permitting Makefile to trivially select kernel/rcupreempt_trace.c.

kernel/Kconfig.preempt

@@ -52,28 +52,3 @@ config PREEMPT
 
 endchoice
 
-config PREEMPT_RCU
-	bool "Preemptible RCU"
-	depends on PREEMPT
-	default n
-	help
-	  This option reduces the latency of the kernel by making certain
-	  RCU sections preemptible. Normally RCU code is non-preemptible, if
-	  this option is selected then read-only RCU sections become
-	  preemptible. This helps latency, but may expose bugs due to
-	  now-naive assumptions about each RCU read-side critical section
-	  remaining on a given CPU through its execution.
-
-	  Say N if you are unsure.
-
-config RCU_TRACE
-	bool "Enable tracing for RCU - currently stats in debugfs"
-	depends on PREEMPT_RCU
-	select DEBUG_FS
-	default y
-	help
-	  This option provides tracing in RCU which presents stats
-	  in debugfs for debugging RCU implementation.
-
-	  Say Y here if you want to enable RCU tracing
-	  Say N if you are unsure.

kernel/Makefile

@@ -74,10 +74,10 @@ obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
 obj-$(CONFIG_SECCOMP) += seccomp.o
 obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
 obj-$(CONFIG_CLASSIC_RCU) += rcuclassic.o
+obj-$(CONFIG_TREE_RCU) += rcutree.o
 obj-$(CONFIG_PREEMPT_RCU) += rcupreempt.o
-ifeq ($(CONFIG_PREEMPT_RCU),y)
-obj-$(CONFIG_RCU_TRACE) += rcupreempt_trace.o
-endif
+obj-$(CONFIG_TREE_RCU_TRACE) += rcutree_trace.o
+obj-$(CONFIG_PREEMPT_RCU_TRACE) += rcupreempt_trace.o
 obj-$(CONFIG_RELAY) += relay.o
 obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
 obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o

kernel/irq/manage.c

@@ -673,6 +673,18 @@ int request_irq(unsigned int irq, irq_handler_t handler,
 	struct irq_desc *desc;
 	int retval;
 
+	/*
+	 * handle_IRQ_event() always ignores IRQF_DISABLED except for
+	 * the _first_ irqaction (sigh).  That can cause oopsing, but
+	 * the behavior is classified as "will not fix" so we need to
+	 * start nudging drivers away from using that idiom.
+	 */
+	if ((irqflags & (IRQF_SHARED|IRQF_DISABLED))
+			== (IRQF_SHARED|IRQF_DISABLED))
+		pr_warning("IRQ %d/%s: IRQF_DISABLED is not "
+				"guaranteed on shared IRQs\n",
+				irq, devname);
+
 #ifdef CONFIG_LOCKDEP
 	/*
 	 * Lockdep wants atomic interrupt handlers:

kernel/lockdep.c

@@ -291,14 +291,12 @@ void lockdep_off(void)
 {
 	current->lockdep_recursion++;
 }
-
 EXPORT_SYMBOL(lockdep_off);
 
 void lockdep_on(void)
 {
 	current->lockdep_recursion--;
 }
-
 EXPORT_SYMBOL(lockdep_on);
 
 /*
@@ -580,7 +578,8 @@ static void print_lock_class_header(struct lock_class *class, int depth)
 /*
  * printk all lock dependencies starting at <entry>:
  */
-static void print_lock_dependencies(struct lock_class *class, int depth)
+static void __used
+print_lock_dependencies(struct lock_class *class, int depth)
 {
 	struct lock_list *entry;
 
@@ -2512,7 +2511,6 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name,
 	if (subclass)
 		register_lock_class(lock, subclass, 1);
 }
-
 EXPORT_SYMBOL_GPL(lockdep_init_map);
 
 /*
@@ -2693,8 +2691,9 @@ static int check_unlock(struct task_struct *curr, struct lockdep_map *lock,
 }
 
 static int
-__lock_set_subclass(struct lockdep_map *lock,
-		    unsigned int subclass, unsigned long ip)
+__lock_set_class(struct lockdep_map *lock, const char *name,
+		 struct lock_class_key *key, unsigned int subclass,
+		 unsigned long ip)
 {
 	struct task_struct *curr = current;
 	struct held_lock *hlock, *prev_hlock;
@@ -2721,6 +2720,7 @@ __lock_set_subclass(struct lockdep_map *lock,
 	return print_unlock_inbalance_bug(curr, lock, ip);
 
 found_it:
+	lockdep_init_map(lock, name, key, 0);
 	class = register_lock_class(lock, subclass, 0);
 	hlock->class_idx = class - lock_classes + 1;
 
@@ -2905,9 +2905,9 @@ static void check_flags(unsigned long flags)
 #endif
 }
 
-void
-lock_set_subclass(struct lockdep_map *lock,
-		  unsigned int subclass, unsigned long ip)
+void lock_set_class(struct lockdep_map *lock, const char *name,
+		    struct lock_class_key *key, unsigned int subclass,
+		    unsigned long ip)
 {
 	unsigned long flags;
 
@@ -2917,13 +2917,12 @@ lock_set_subclass(struct lockdep_map *lock,
 	raw_local_irq_save(flags);
 	current->lockdep_recursion = 1;
 	check_flags(flags);
-	if (__lock_set_subclass(lock, subclass, ip))
+	if (__lock_set_class(lock, name, key, subclass, ip))
 		check_chain_key(current);
 	current->lockdep_recursion = 0;
 	raw_local_irq_restore(flags);
 }
-
-EXPORT_SYMBOL_GPL(lock_set_subclass);
+EXPORT_SYMBOL_GPL(lock_set_class);
 
 /*
  * We are not always called with irqs disabled - do that here,
@@ -2947,7 +2946,6 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 	current->lockdep_recursion = 0;
 	raw_local_irq_restore(flags);
 }
-
 EXPORT_SYMBOL_GPL(lock_acquire);
 
 void lock_release(struct lockdep_map *lock, int nested,
@@ -2965,7 +2963,6 @@ void lock_release(struct lockdep_map *lock, int nested,
 	current->lockdep_recursion = 0;
 	raw_local_irq_restore(flags);
 }
-
 EXPORT_SYMBOL_GPL(lock_release);
 
 #ifdef CONFIG_LOCK_STAT
@@ -3450,7 +3447,6 @@ void debug_show_all_locks(void)
 	if (unlock)
 		read_unlock(&tasklist_lock);
 }
-
 EXPORT_SYMBOL_GPL(debug_show_all_locks);
 
 /*
@@ -3471,7 +3467,6 @@ void debug_show_held_locks(struct task_struct *task)
 {
 		__debug_show_held_locks(task);
 }
-
 EXPORT_SYMBOL_GPL(debug_show_held_locks);
 
 void lockdep_sys_exit(void)

kernel/printk.c

@@ -662,7 +662,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
 	if (recursion_bug) {
 		recursion_bug = 0;
 		strcpy(printk_buf, recursion_bug_msg);
-		printed_len = sizeof(recursion_bug_msg);
+		printed_len = strlen(recursion_bug_msg);
 	}
 	/* Emit the output into the temporary buffer */
 	printed_len += vscnprintf(printk_buf + printed_len,

kernel/rcupreempt.c

@@ -551,6 +551,16 @@ void rcu_irq_exit(void)
 	}
 }
 
+void rcu_nmi_enter(void)
+{
+	rcu_irq_enter();
+}
+
+void rcu_nmi_exit(void)
+{
+	rcu_irq_exit();
+}
+
 static void dyntick_save_progress_counter(int cpu)
 {
 	struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu);

kernel/rcupreempt_trace.c

@@ -149,12 +149,12 @@ static void rcupreempt_trace_sum(struct rcupreempt_trace *sp)
 		sp->done_length += cp->done_length;
 		sp->done_add += cp->done_add;
 		sp->done_remove += cp->done_remove;
-		atomic_set(&sp->done_invoked, atomic_read(&cp->done_invoked));
+		atomic_add(atomic_read(&cp->done_invoked), &sp->done_invoked);
 		sp->rcu_check_callbacks += cp->rcu_check_callbacks;
-		atomic_set(&sp->rcu_try_flip_1,
-			   atomic_read(&cp->rcu_try_flip_1));
-		atomic_set(&sp->rcu_try_flip_e1,
-			   atomic_read(&cp->rcu_try_flip_e1));
+		atomic_add(atomic_read(&cp->rcu_try_flip_1),
+			   &sp->rcu_try_flip_1);
+		atomic_add(atomic_read(&cp->rcu_try_flip_e1),
+			   &sp->rcu_try_flip_e1);
 		sp->rcu_try_flip_i1 += cp->rcu_try_flip_i1;
 		sp->rcu_try_flip_ie1 += cp->rcu_try_flip_ie1;
 		sp->rcu_try_flip_g1 += cp->rcu_try_flip_g1;

kernel/rcutorture.c

@@ -39,6 +39,7 @@
 #include <linux/moduleparam.h>
 #include <linux/percpu.h>
 #include <linux/notifier.h>
+#include <linux/reboot.h>
 #include <linux/freezer.h>
 #include <linux/cpu.h>
 #include <linux/delay.h>
@@ -108,7 +109,6 @@ struct rcu_torture {
 	int rtort_mbtest;
 };
 
-static int fullstop = 0;	/* stop generating callbacks at test end. */
 static LIST_HEAD(rcu_torture_freelist);
 static struct rcu_torture *rcu_torture_current = NULL;
 static long rcu_torture_current_version = 0;
@@ -136,6 +136,30 @@ static int stutter_pause_test = 0;
 #endif
 int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT;
 
+#define FULLSTOP_SIGNALED 1	/* Bail due to signal. */
+#define FULLSTOP_CLEANUP  2	/* Orderly shutdown. */
+static int fullstop;		/* stop generating callbacks at test end. */
+DEFINE_MUTEX(fullstop_mutex);	/* protect fullstop transitions and */
+				/*  spawning of kthreads. */
+
+/*
+ * Detect and respond to a signal-based shutdown.
+ */
+static int
+rcutorture_shutdown_notify(struct notifier_block *unused1,
+			   unsigned long unused2, void *unused3)
+{
+	if (fullstop)
+		return NOTIFY_DONE;
+	if (signal_pending(current)) {
+		mutex_lock(&fullstop_mutex);
+		if (!ACCESS_ONCE(fullstop))
+			fullstop = FULLSTOP_SIGNALED;
+		mutex_unlock(&fullstop_mutex);
+	}
+	return NOTIFY_DONE;
+}
+
 /*
  * Allocate an element from the rcu_tortures pool.
  */
@@ -199,11 +223,12 @@ rcu_random(struct rcu_random_state *rrsp)
 static void
 rcu_stutter_wait(void)
 {
-	while (stutter_pause_test || !rcutorture_runnable)
+	while ((stutter_pause_test || !rcutorture_runnable) && !fullstop) {
 		if (rcutorture_runnable)
 			schedule_timeout_interruptible(1);
 		else
 			schedule_timeout_interruptible(round_jiffies_relative(HZ));
+	}
 }
 
 /*
@@ -599,7 +624,7 @@ rcu_torture_writer(void *arg)
 		rcu_stutter_wait();
 	} while (!kthread_should_stop() && !fullstop);
 	VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
-	while (!kthread_should_stop())
+	while (!kthread_should_stop() && fullstop != FULLSTOP_SIGNALED)
 		schedule_timeout_uninterruptible(1);
 	return 0;
 }
@@ -624,7 +649,7 @@ rcu_torture_fakewriter(void *arg)
 	} while (!kthread_should_stop() && !fullstop);
 
 	VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
-	while (!kthread_should_stop())
+	while (!kthread_should_stop() && fullstop != FULLSTOP_SIGNALED)
 		schedule_timeout_uninterruptible(1);
 	return 0;
 }
@@ -734,7 +759,7 @@ rcu_torture_reader(void *arg)
 	VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
 	if (irqreader && cur_ops->irqcapable)
 		del_timer_sync(&t);
-	while (!kthread_should_stop())
+	while (!kthread_should_stop() && fullstop != FULLSTOP_SIGNALED)
 		schedule_timeout_uninterruptible(1);
 	return 0;
 }
@@ -831,7 +856,7 @@ rcu_torture_stats(void *arg)
 	do {
 		schedule_timeout_interruptible(stat_interval * HZ);
 		rcu_torture_stats_print();
-	} while (!kthread_should_stop());
+	} while (!kthread_should_stop() && !fullstop);
 	VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping");
 	return 0;
 }
@@ -899,7 +924,7 @@ rcu_torture_shuffle(void *arg)
 	do {
 		schedule_timeout_interruptible(shuffle_interval * HZ);
 		rcu_torture_shuffle_tasks();
-	} while (!kthread_should_stop());
+	} while (!kthread_should_stop() && !fullstop);
 	VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping");
 	return 0;
 }
@@ -914,10 +939,10 @@ rcu_torture_stutter(void *arg)
 	do {
 		schedule_timeout_interruptible(stutter * HZ);
 		stutter_pause_test = 1;
-		if (!kthread_should_stop())
+		if (!kthread_should_stop() && !fullstop)
 			schedule_timeout_interruptible(stutter * HZ);
 		stutter_pause_test = 0;
-	} while (!kthread_should_stop());
+	} while (!kthread_should_stop() && !fullstop);
 	VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping");
 	return 0;
 }
@@ -934,12 +959,27 @@ rcu_torture_print_module_parms(char *tag)
 		stutter, irqreader);
 }
 
+static struct notifier_block rcutorture_nb = {
+	.notifier_call = rcutorture_shutdown_notify,
+};
+
 static void
 rcu_torture_cleanup(void)
 {
 	int i;
 
-	fullstop = 1;
+	mutex_lock(&fullstop_mutex);
+	if (!fullstop) {
+		/* If being signaled, let it happen, then exit. */
+		mutex_unlock(&fullstop_mutex);
+		schedule_timeout_interruptible(10 * HZ);
+		if (cur_ops->cb_barrier != NULL)
+			cur_ops->cb_barrier();
+		return;
+	}
+	fullstop = FULLSTOP_CLEANUP;
+	mutex_unlock(&fullstop_mutex);
+	unregister_reboot_notifier(&rcutorture_nb);
 	if (stutter_task) {
 		VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task");
 		kthread_stop(stutter_task);
@@ -1015,6 +1055,8 @@ rcu_torture_init(void)
 		{ &rcu_ops, &rcu_sync_ops, &rcu_bh_ops, &rcu_bh_sync_ops,
 		  &srcu_ops, &sched_ops, &sched_ops_sync, };
 
+	mutex_lock(&fullstop_mutex);
+
 	/* Process args and tell the world that the torturer is on the job. */
 	for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
 		cur_ops = torture_ops[i];
@@ -1024,6 +1066,7 @@ rcu_torture_init(void)
 	if (i == ARRAY_SIZE(torture_ops)) {
 		printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n",
 		       torture_type);
+		mutex_unlock(&fullstop_mutex);
 		return (-EINVAL);
 	}
 	if (cur_ops->init)
@@ -1146,9 +1189,12 @@ rcu_torture_init(void)
 			goto unwind;
 		}
 	}
+	register_reboot_notifier(&rcutorture_nb);
+	mutex_unlock(&fullstop_mutex);
 	return 0;
 
 unwind:
+	mutex_unlock(&fullstop_mutex);
 	rcu_torture_cleanup();
 	return firsterr;
 }

kernel/rcutree_trace.c

+/*
+ * Read-Copy Update tracing for classic implementation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright IBM Corporation, 2008
+ *
+ * Papers:  http://www.rdrop.com/users/paulmck/RCU
+ *
+ * For detailed explanation of Read-Copy Update mechanism see -
+ * 		Documentation/RCU
+ *
+ */
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/rcupdate.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <asm/atomic.h>
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/completion.h>
+#include <linux/moduleparam.h>
+#include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/cpu.h>
+#include <linux/mutex.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
+{
+	if (!rdp->beenonline)
+		return;
+	seq_printf(m, "%3d%cc=%ld g=%ld pq=%d pqc=%ld qp=%d rpfq=%ld rp=%x",
+		   rdp->cpu,
+		   cpu_is_offline(rdp->cpu) ? '!' : ' ',
+		   rdp->completed, rdp->gpnum,
+		   rdp->passed_quiesc, rdp->passed_quiesc_completed,
+		   rdp->qs_pending,
+		   rdp->n_rcu_pending_force_qs - rdp->n_rcu_pending,
+		   (int)(rdp->n_rcu_pending & 0xffff));
+#ifdef CONFIG_NO_HZ
+	seq_printf(m, " dt=%d/%d dn=%d df=%lu",
+		   rdp->dynticks->dynticks,
+		   rdp->dynticks->dynticks_nesting,
+		   rdp->dynticks->dynticks_nmi,
+		   rdp->dynticks_fqs);
+#endif /* #ifdef CONFIG_NO_HZ */
+	seq_printf(m, " of=%lu ri=%lu", rdp->offline_fqs, rdp->resched_ipi);
+	seq_printf(m, " ql=%ld b=%ld\n", rdp->qlen, rdp->blimit);
+}
+
+#define PRINT_RCU_DATA(name, func, m) \
+	do { \
+		int _p_r_d_i; \
+		\
+		for_each_possible_cpu(_p_r_d_i) \
+			func(m, &per_cpu(name, _p_r_d_i)); \
+	} while (0)
+
+static int show_rcudata(struct seq_file *m, void *unused)
+{
+	seq_puts(m, "rcu:\n");
+	PRINT_RCU_DATA(rcu_data, print_one_rcu_data, m);
+	seq_puts(m, "rcu_bh:\n");
+	PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data, m);
+	return 0;
+}
+
+static int rcudata_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, show_rcudata, NULL);
+}
+
+static struct file_operations rcudata_fops = {
+	.owner = THIS_MODULE,
+	.open = rcudata_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
+{
+	if (!rdp->beenonline)
+		return;
+	seq_printf(m, "%d,%s,%ld,%ld,%d,%ld,%d,%ld,%ld",
+		   rdp->cpu,
+		   cpu_is_offline(rdp->cpu) ? "\"Y\"" : "\"N\"",
+		   rdp->completed, rdp->gpnum,
+		   rdp->passed_quiesc, rdp->passed_quiesc_completed,
+		   rdp->qs_pending,
+		   rdp->n_rcu_pending_force_qs - rdp->n_rcu_pending,
+		   rdp->n_rcu_pending);
+#ifdef CONFIG_NO_HZ
+	seq_printf(m, ",%d,%d,%d,%lu",
+		   rdp->dynticks->dynticks,
+		   rdp->dynticks->dynticks_nesting,
+		   rdp->dynticks->dynticks_nmi,
+		   rdp->dynticks_fqs);
+#endif /* #ifdef CONFIG_NO_HZ */
+	seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi);
+	seq_printf(m, ",%ld,%ld\n", rdp->qlen, rdp->blimit);
+}
+
+static int show_rcudata_csv(struct seq_file *m, void *unused)
+{
+	seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pqc\",\"pq\",\"rpfq\",\"rp\",");
+#ifdef CONFIG_NO_HZ
+	seq_puts(m, "\"dt\",\"dt nesting\",\"dn\",\"df\",");
+#endif /* #ifdef CONFIG_NO_HZ */
+	seq_puts(m, "\"of\",\"ri\",\"ql\",\"b\"\n");
+	seq_puts(m, "\"rcu:\"\n");
+	PRINT_RCU_DATA(rcu_data, print_one_rcu_data_csv, m);
+	seq_puts(m, "\"rcu_bh:\"\n");
+	PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data_csv, m);
+	return 0;
+}
+
+static int rcudata_csv_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, show_rcudata_csv, NULL);
+}
+
+static struct file_operations rcudata_csv_fops = {
+	.owner = THIS_MODULE,
+	.open = rcudata_csv_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
+{
+	int level = 0;
+	struct rcu_node *rnp;
+
+	seq_printf(m, "c=%ld g=%ld s=%d jfq=%ld j=%x "
+	              "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu\n",
+		   rsp->completed, rsp->gpnum, rsp->signaled,
+		   (long)(rsp->jiffies_force_qs - jiffies),
+		   (int)(jiffies & 0xffff),
+		   rsp->n_force_qs, rsp->n_force_qs_ngp,
+		   rsp->n_force_qs - rsp->n_force_qs_ngp,
+		   rsp->n_force_qs_lh);
+	for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) {
+		if (rnp->level != level) {
+			seq_puts(m, "\n");
+			level = rnp->level;
+		}
+		seq_printf(m, "%lx/%lx %d:%d ^%d    ",
+			   rnp->qsmask, rnp->qsmaskinit,
+			   rnp->grplo, rnp->grphi, rnp->grpnum);
+	}
+	seq_puts(m, "\n");
+}
+
+static int show_rcuhier(struct seq_file *m, void *unused)
+{
+	seq_puts(m, "rcu:\n");
+	print_one_rcu_state(m, &rcu_state);
+	seq_puts(m, "rcu_bh:\n");
+	print_one_rcu_state(m, &rcu_bh_state);
+	return 0;
+}
+
+static int rcuhier_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, show_rcuhier, NULL);
+}
+
+static struct file_operations rcuhier_fops = {
+	.owner = THIS_MODULE,
+	.open = rcuhier_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static int show_rcugp(struct seq_file *m, void *unused)
+{
+	seq_printf(m, "rcu: completed=%ld  gpnum=%ld\n",
+		   rcu_state.completed, rcu_state.gpnum);
+	seq_printf(m, "rcu_bh: completed=%ld  gpnum=%ld\n",
+		   rcu_bh_state.completed, rcu_bh_state.gpnum);
+	return 0;
+}
+
+static int rcugp_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, show_rcugp, NULL);
+}
+
+static struct file_operations rcugp_fops = {
+	.owner = THIS_MODULE,
+	.open = rcugp_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static struct dentry *rcudir, *datadir, *datadir_csv, *hierdir, *gpdir;
+static int __init rcuclassic_trace_init(void)
+{
+	rcudir = debugfs_create_dir("rcu", NULL);
+	if (!rcudir)
+		goto out;
+
+	datadir = debugfs_create_file("rcudata", 0444, rcudir,
+						NULL, &rcudata_fops);
+	if (!datadir)
+		goto free_out;
+
+	datadir_csv = debugfs_create_file("rcudata.csv", 0444, rcudir,
+						NULL, &rcudata_csv_fops);
+	if (!datadir_csv)
+		goto free_out;
+
+	gpdir = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops);
+	if (!gpdir)
+		goto free_out;
+
+	hierdir = debugfs_create_file("rcuhier", 0444, rcudir,
+						NULL, &rcuhier_fops);
+	if (!hierdir)
+		goto free_out;
+	return 0;
+free_out:
+	if (datadir)
+		debugfs_remove(datadir);
+	if (datadir_csv)
+		debugfs_remove(datadir_csv);
+	if (gpdir)
+		debugfs_remove(gpdir);
+	debugfs_remove(rcudir);
+out:
+	return 1;
+}
+
+static void __exit rcuclassic_trace_cleanup(void)
+{
+	debugfs_remove(datadir);
+	debugfs_remove(datadir_csv);
+	debugfs_remove(gpdir);
+	debugfs_remove(hierdir);
+	debugfs_remove(rcudir);
+}
+
+
+module_init(rcuclassic_trace_init);
+module_exit(rcuclassic_trace_cleanup);
+
+MODULE_AUTHOR("Paul E. McKenney");
+MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation");
+MODULE_LICENSE("GPL");

kernel/resource.c

@@ -853,6 +853,15 @@ int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
 		if (PFN_DOWN(p->start) <= PFN_DOWN(addr) &&
 		    PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1))
 			continue;
+		/*
+		 * if a resource is "BUSY", it's not a hardware resource
+		 * but a driver mapping of such a resource; we don't want
+		 * to warn for those; some drivers legitimately map only
+		 * partial hardware resources. (example: vesafb)
+		 */
+		if (p->flags & IORESOURCE_BUSY)
+			continue;
+
 		printk(KERN_WARNING "resource map sanity check conflict: "
 		       "0x%llx 0x%llx 0x%llx 0x%llx %s\n",
 		       (unsigned long long)addr,

kernel/softirq.c

@@ -102,20 +102,6 @@ void local_bh_disable(void)
 
 EXPORT_SYMBOL(local_bh_disable);
 
-void __local_bh_enable(void)
-{
-	WARN_ON_ONCE(in_irq());
-
-	/*
-	 * softirqs should never be enabled by __local_bh_enable(),
-	 * it always nests inside local_bh_enable() sections:
-	 */
-	WARN_ON_ONCE(softirq_count() == SOFTIRQ_OFFSET);
-
-	sub_preempt_count(SOFTIRQ_OFFSET);
-}
-EXPORT_SYMBOL_GPL(__local_bh_enable);
-
 /*
  * Special-case - softirqs can safely be enabled in
  * cond_resched_softirq(), or by __do_softirq(),
@@ -269,6 +255,7 @@ void irq_enter(void)
 {
 	int cpu = smp_processor_id();
 
+	rcu_irq_enter();
 	if (idle_cpu(cpu) && !in_interrupt()) {
 		__irq_enter();
 		tick_check_idle(cpu);
@@ -295,9 +282,9 @@ void irq_exit(void)
 
 #ifdef CONFIG_NO_HZ
 	/* Make sure that timer wheel updates are propagated */
-	if (!in_interrupt() && idle_cpu(smp_processor_id()) && !need_resched())
-		tick_nohz_stop_sched_tick(0);
 	rcu_irq_exit();
+	if (idle_cpu(smp_processor_id()) && !in_interrupt() && !need_resched())
+		tick_nohz_stop_sched_tick(0);
 #endif
 	preempt_enable_no_resched();
 }

kernel/stacktrace.c

@@ -6,6 +6,7 @@
  *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
  */
 #include <linux/sched.h>
+#include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/kallsyms.h>
 #include <linux/stacktrace.h>
@@ -24,3 +25,13 @@ void print_stack_trace(struct stack_trace *trace, int spaces)
 }
 EXPORT_SYMBOL_GPL(print_stack_trace);
 
+/*
+ * Architectures that do not implement save_stack_trace_tsk get this
+ * weak alias and a once-per-bootup warning (whenever this facility
+ * is utilized - for example by procfs):
+ */
+__weak void
+save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+	WARN_ONCE(1, KERN_INFO "save_stack_trace_tsk() not implemented yet.\n");
+}

lib/Kconfig.debug

@@ -252,6 +252,14 @@ config DEBUG_OBJECTS_TIMERS
 	  timer routines to track the life time of timer objects and
 	  validate the timer operations.
 
+config DEBUG_OBJECTS_ENABLE_DEFAULT
+	int "debug_objects bootup default value (0-1)"
+        range 0 1
+        default "1"
+        depends on DEBUG_OBJECTS
+        help
+          Debug objects boot parameter default value
+
 config DEBUG_SLAB
 	bool "Debug slab memory allocations"
 	depends on DEBUG_KERNEL && SLAB
@@ -629,6 +637,19 @@ config RCU_CPU_STALL_DETECTOR
 
 	  Say N if you are unsure.
 
+config RCU_CPU_STALL_DETECTOR
+	bool "Check for stalled CPUs delaying RCU grace periods"
+	depends on CLASSIC_RCU || TREE_RCU
+	default n
+	help
+	  This option causes RCU to printk information on which
+	  CPUs are delaying the current grace period, but only when
+	  the grace period extends for excessive time periods.
+
+	  Say Y if you want RCU to perform such checks.
+
+	  Say N if you are unsure.
+
 config KPROBES_SANITY_TEST
 	bool "Kprobes sanity tests"
 	depends on DEBUG_KERNEL

lib/debugobjects.c

@@ -45,7 +45,9 @@ static struct kmem_cache	*obj_cache;
 static int			debug_objects_maxchain __read_mostly;
 static int			debug_objects_fixups __read_mostly;
 static int			debug_objects_warnings __read_mostly;
-static int			debug_objects_enabled __read_mostly;
+static int			debug_objects_enabled __read_mostly
+				= CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
+
 static struct debug_obj_descr	*descr_test  __read_mostly;
 
 static int __init enable_object_debug(char *str)