Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
authorLinus Torvalds <torvalds@linux-foundation.org>
Tue, 31 Mar 2009 00:17:35 +0000 (17:17 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 31 Mar 2009 00:17:35 +0000 (17:17 -0700)
* 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (33 commits)
  lockdep: fix deadlock in lockdep_trace_alloc
  lockdep: annotate reclaim context (__GFP_NOFS), fix SLOB
  lockdep: annotate reclaim context (__GFP_NOFS), fix
  lockdep: build fix for !PROVE_LOCKING
  lockstat: warn about disabled lock debugging
  lockdep: use stringify.h
  lockdep: simplify check_prev_add_irq()
  lockdep: get_user_chars() redo
  lockdep: simplify get_user_chars()
  lockdep: add comments to mark_lock_irq()
  lockdep: remove macro usage from mark_held_locks()
  lockdep: fully reduce mark_lock_irq()
  lockdep: merge the !_READ mark_lock_irq() helpers
  lockdep: merge the _READ mark_lock_irq() helpers
  lockdep: simplify mark_lock_irq() helpers #3
  lockdep: further simplify mark_lock_irq() helpers
  lockdep: simplify the mark_lock_irq() helpers
  lockdep: split up mark_lock_irq()
  lockdep: generate usage strings
  lockdep: generate the state bit definitions
  ...

21 files changed:
Documentation/lockdep-design.txt
include/linux/lockdep.h
include/linux/mutex.h
include/linux/sched.h
include/linux/timer.h
kernel/lockdep.c
kernel/lockdep_internals.h
kernel/lockdep_proc.c
kernel/lockdep_states.h [new file with mode: 0644]
kernel/mutex-debug.c
kernel/mutex-debug.h
kernel/mutex.c
kernel/mutex.h
kernel/sched.c
kernel/sched_features.h
kernel/timer.c
mm/page_alloc.c
mm/slab.c
mm/slob.c
mm/slub.c
mm/vmscan.c

index 488773018152056ea159685e732e42452a7ae142..938ea22f2cc096f6838a678217e463bf9ec0cd4d 100644 (file)
@@ -27,33 +27,37 @@ lock-class.
 State
 -----
 
-The validator tracks lock-class usage history into 5 separate state bits:
+The validator tracks lock-class usage history into 4n + 1 separate state bits:
 
-- 'ever held in hardirq context'                    [ == hardirq-safe   ]
-- 'ever held in softirq context'                    [ == softirq-safe   ]
-- 'ever held with hardirqs enabled'                 [ == hardirq-unsafe ]
-- 'ever held with softirqs and hardirqs enabled'    [ == softirq-unsafe ]
+- 'ever held in STATE context'
+- 'ever head as readlock in STATE context'
+- 'ever head with STATE enabled'
+- 'ever head as readlock with STATE enabled'
+
+Where STATE can be either one of (kernel/lockdep_states.h)
+ - hardirq
+ - softirq
+ - reclaim_fs
 
 - 'ever used'                                       [ == !unused        ]
 
-When locking rules are violated, these state bits are presented in the
-locking error messages, inside curlies.  A contrived example:
+When locking rules are violated, these state bits are presented in the
+locking error messages, inside curlies. A contrived example:
 
    modprobe/2287 is trying to acquire lock:
-    (&sio_locks[i].lock){--..}, at: [<c02867fd>] mutex_lock+0x21/0x24
+    (&sio_locks[i].lock){-.-...}, at: [<c02867fd>] mutex_lock+0x21/0x24
 
    but task is already holding lock:
-    (&sio_locks[i].lock){--..}, at: [<c02867fd>] mutex_lock+0x21/0x24
+    (&sio_locks[i].lock){-.-...}, at: [<c02867fd>] mutex_lock+0x21/0x24
 
 
-The bit position indicates hardirq, softirq, hardirq-read,
-softirq-read respectively, and the character displayed in each
-indicates:
+The bit position indicates STATE, STATE-read, for each of the states listed
+above, and the character displayed in each indicates:
 
    '.'  acquired while irqs disabled
    '+'  acquired in irq context
    '-'  acquired with irqs enabled
-   '?' read acquired in irq context with irqs enabled.
+   '?'  acquired in irq context with irqs enabled.
 
 Unused mutexes cannot be part of the cause of an error.
 
index 23bf02fb124ffae0dfb282453582385ea34d1919..5a58ea3e91e94e5aca9c67811cb853ff05a1ec84 100644 (file)
@@ -20,43 +20,10 @@ struct lockdep_map;
 #include <linux/stacktrace.h>
 
 /*
- * Lock-class usage-state bits:
+ * We'd rather not expose kernel/lockdep_states.h this wide, but we do need
+ * the total number of states... :-(
  */
-enum lock_usage_bit
-{
-       LOCK_USED = 0,
-       LOCK_USED_IN_HARDIRQ,
-       LOCK_USED_IN_SOFTIRQ,
-       LOCK_ENABLED_SOFTIRQS,
-       LOCK_ENABLED_HARDIRQS,
-       LOCK_USED_IN_HARDIRQ_READ,
-       LOCK_USED_IN_SOFTIRQ_READ,
-       LOCK_ENABLED_SOFTIRQS_READ,
-       LOCK_ENABLED_HARDIRQS_READ,
-       LOCK_USAGE_STATES
-};
-
-/*
- * Usage-state bitmasks:
- */
-#define LOCKF_USED                     (1 << LOCK_USED)
-#define LOCKF_USED_IN_HARDIRQ          (1 << LOCK_USED_IN_HARDIRQ)
-#define LOCKF_USED_IN_SOFTIRQ          (1 << LOCK_USED_IN_SOFTIRQ)
-#define LOCKF_ENABLED_HARDIRQS         (1 << LOCK_ENABLED_HARDIRQS)
-#define LOCKF_ENABLED_SOFTIRQS         (1 << LOCK_ENABLED_SOFTIRQS)
-
-#define LOCKF_ENABLED_IRQS (LOCKF_ENABLED_HARDIRQS | LOCKF_ENABLED_SOFTIRQS)
-#define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ)
-
-#define LOCKF_USED_IN_HARDIRQ_READ     (1 << LOCK_USED_IN_HARDIRQ_READ)
-#define LOCKF_USED_IN_SOFTIRQ_READ     (1 << LOCK_USED_IN_SOFTIRQ_READ)
-#define LOCKF_ENABLED_HARDIRQS_READ    (1 << LOCK_ENABLED_HARDIRQS_READ)
-#define LOCKF_ENABLED_SOFTIRQS_READ    (1 << LOCK_ENABLED_SOFTIRQS_READ)
-
-#define LOCKF_ENABLED_IRQS_READ \
-               (LOCKF_ENABLED_HARDIRQS_READ | LOCKF_ENABLED_SOFTIRQS_READ)
-#define LOCKF_USED_IN_IRQ_READ \
-               (LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)
+#define XXX_LOCK_USAGE_STATES          (1+3*4)
 
 #define MAX_LOCKDEP_SUBCLASSES         8UL
 
@@ -97,7 +64,7 @@ struct lock_class {
         * IRQ/softirq usage tracking bits:
         */
        unsigned long                   usage_mask;
-       struct stack_trace              usage_traces[LOCK_USAGE_STATES];
+       struct stack_trace              usage_traces[XXX_LOCK_USAGE_STATES];
 
        /*
         * These fields represent a directed graph of lock dependencies,
@@ -324,7 +291,11 @@ static inline void lock_set_subclass(struct lockdep_map *lock,
        lock_set_class(lock, lock->name, lock->key, subclass, ip);
 }
 
-# define INIT_LOCKDEP                          .lockdep_recursion = 0,
+extern void lockdep_set_current_reclaim_state(gfp_t gfp_mask);
+extern void lockdep_clear_current_reclaim_state(void);
+extern void lockdep_trace_alloc(gfp_t mask);
+
+# define INIT_LOCKDEP                          .lockdep_recursion = 0, .lockdep_reclaim_gfp = 0,
 
 #define lockdep_depth(tsk)     (debug_locks ? (tsk)->lockdep_depth : 0)
 
@@ -342,6 +313,9 @@ static inline void lockdep_on(void)
 # 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_set_current_reclaim_state(g)  do { } while (0)
+# define lockdep_clear_current_reclaim_state() do { } while (0)
+# define lockdep_trace_alloc(g)                        do { } while (0)
 # define lockdep_init()                                do { } while (0)
 # define lockdep_info()                                do { } while (0)
 # define lockdep_init_map(lock, name, key, sub) \
index 7a0e5c4f8072c53f4b0d6a7dfa681355324e065f..3069ec7e0ab84ca54a282c72d73385e44e69d63a 100644 (file)
@@ -50,8 +50,10 @@ struct mutex {
        atomic_t                count;
        spinlock_t              wait_lock;
        struct list_head        wait_list;
-#ifdef CONFIG_DEBUG_MUTEXES
+#if defined(CONFIG_DEBUG_MUTEXES) || defined(CONFIG_SMP)
        struct thread_info      *owner;
+#endif
+#ifdef CONFIG_DEBUG_MUTEXES
        const char              *name;
        void                    *magic;
 #endif
@@ -68,7 +70,6 @@ struct mutex_waiter {
        struct list_head        list;
        struct task_struct      *task;
 #ifdef CONFIG_DEBUG_MUTEXES
-       struct mutex            *lock;
        void                    *magic;
 #endif
 };
index 1d19c025f9d2e78b34692b3f350d9bef6fe522ed..29df6374d2de517e078c7dd29dd5eb6b7c18f82b 100644 (file)
@@ -331,7 +331,9 @@ extern signed long schedule_timeout(signed long timeout);
 extern signed long schedule_timeout_interruptible(signed long timeout);
 extern signed long schedule_timeout_killable(signed long timeout);
 extern signed long schedule_timeout_uninterruptible(signed long timeout);
+asmlinkage void __schedule(void);
 asmlinkage void schedule(void);
+extern int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner);
 
 struct nsproxy;
 struct user_namespace;
@@ -1334,6 +1336,7 @@ struct task_struct {
        int lockdep_depth;
        unsigned int lockdep_recursion;
        struct held_lock held_locks[MAX_LOCK_DEPTH];
+       gfp_t lockdep_reclaim_gfp;
 #endif
 
 /* journalling filesystem info */
index e2d662e3416e38026bbc7385f744481de1b7d0a0..6cdb6f3331f11b6a80d7cd2c85a45706937b16d3 100644 (file)
@@ -5,6 +5,7 @@
 #include <linux/ktime.h>
 #include <linux/stddef.h>
 #include <linux/debugobjects.h>
+#include <linux/stringify.h>
 
 struct tvec_base;
 
@@ -21,52 +22,126 @@ struct timer_list {
        char start_comm[16];
        int start_pid;
 #endif
+#ifdef CONFIG_LOCKDEP
+       struct lockdep_map lockdep_map;
+#endif
 };
 
 extern struct tvec_base boot_tvec_bases;
 
+#ifdef CONFIG_LOCKDEP
+/*
+ * NB: because we have to copy the lockdep_map, setting the lockdep_map key
+ * (second argument) here is required, otherwise it could be initialised to
+ * the copy of the lockdep_map later! We use the pointer to and the string
+ * "<file>:<line>" as the key resp. the name of the lockdep_map.
+ */
+#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)                           \
+       .lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
+#else
+#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
+#endif
+
 #define TIMER_INITIALIZER(_function, _expires, _data) {                \
                .entry = { .prev = TIMER_ENTRY_STATIC },        \
                .function = (_function),                        \
                .expires = (_expires),                          \
                .data = (_data),                                \
                .base = &boot_tvec_bases,                       \
+               __TIMER_LOCKDEP_MAP_INITIALIZER(                \
+                       __FILE__ ":" __stringify(__LINE__))     \
        }
 
 #define DEFINE_TIMER(_name, _function, _expires, _data)                \
        struct timer_list _name =                               \
                TIMER_INITIALIZER(_function, _expires, _data)
 
-void init_timer(struct timer_list *timer);
-void init_timer_deferrable(struct timer_list *timer);
+void init_timer_key(struct timer_list *timer,
+                   const char *name,
+                   struct lock_class_key *key);
+void init_timer_deferrable_key(struct timer_list *timer,
+                              const char *name,
+                              struct lock_class_key *key);
+
+#ifdef CONFIG_LOCKDEP
+#define init_timer(timer)                                              \
+       do {                                                            \
+               static struct lock_class_key __key;                     \
+               init_timer_key((timer), #timer, &__key);                \
+       } while (0)
+
+#define init_timer_deferrable(timer)                                   \
+       do {                                                            \
+               static struct lock_class_key __key;                     \
+               init_timer_deferrable_key((timer), #timer, &__key);     \
+       } while (0)
+
+#define init_timer_on_stack(timer)                                     \
+       do {                                                            \
+               static struct lock_class_key __key;                     \
+               init_timer_on_stack_key((timer), #timer, &__key);       \
+       } while (0)
+
+#define setup_timer(timer, fn, data)                                   \
+       do {                                                            \
+               static struct lock_class_key __key;                     \
+               setup_timer_key((timer), #timer, &__key, (fn), (data));\
+       } while (0)
+
+#define setup_timer_on_stack(timer, fn, data)                          \
+       do {                                                            \
+               static struct lock_class_key __key;                     \
+               setup_timer_on_stack_key((timer), #timer, &__key,       \
+                                        (fn), (data));                 \
+       } while (0)
+#else
+#define init_timer(timer)\
+       init_timer_key((timer), NULL, NULL)
+#define init_timer_deferrable(timer)\
+       init_timer_deferrable_key((timer), NULL, NULL)
+#define init_timer_on_stack(timer)\
+       init_timer_on_stack_key((timer), NULL, NULL)
+#define setup_timer(timer, fn, data)\
+       setup_timer_key((timer), NULL, NULL, (fn), (data))
+#define setup_timer_on_stack(timer, fn, data)\
+       setup_timer_on_stack_key((timer), NULL, NULL, (fn), (data))
+#endif
 
 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
-extern void init_timer_on_stack(struct timer_list *timer);
+extern void init_timer_on_stack_key(struct timer_list *timer,
+                                   const char *name,
+                                   struct lock_class_key *key);
 extern void destroy_timer_on_stack(struct timer_list *timer);
 #else
 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
-static inline void init_timer_on_stack(struct timer_list *timer)
+static inline void init_timer_on_stack_key(struct timer_list *timer,
+                                          const char *name,
+                                          struct lock_class_key *key)
 {
-       init_timer(timer);
+       init_timer_key(timer, name, key);
 }
 #endif
 
-static inline void setup_timer(struct timer_list * timer,
+static inline void setup_timer_key(struct timer_list * timer,
+                               const char *name,
+                               struct lock_class_key *key,
                                void (*function)(unsigned long),
                                unsigned long data)
 {
        timer->function = function;
        timer->data = data;
-       init_timer(timer);
+       init_timer_key(timer, name, key);
 }
 
-static inline void setup_timer_on_stack(struct timer_list *timer,
+static inline void setup_timer_on_stack_key(struct timer_list *timer,
+                                       const char *name,
+                                       struct lock_class_key *key,
                                        void (*function)(unsigned long),
                                        unsigned long data)
 {
        timer->function = function;
        timer->data = data;
-       init_timer_on_stack(timer);
+       init_timer_on_stack_key(timer, name, key);
 }
 
 /**
index 06b0c3568f0b230a8c6b669d055c8c442a7eb790..3673a3f44d9d445f7cdf42f2ee5592731a4c0db7 100644 (file)
@@ -41,6 +41,7 @@
 #include <linux/utsname.h>
 #include <linux/hash.h>
 #include <linux/ftrace.h>
+#include <linux/stringify.h>
 
 #include <asm/sections.h>
 
@@ -310,12 +311,14 @@ EXPORT_SYMBOL(lockdep_on);
 #if VERBOSE
 # define HARDIRQ_VERBOSE       1
 # define SOFTIRQ_VERBOSE       1
+# define RECLAIM_VERBOSE       1
 #else
 # define HARDIRQ_VERBOSE       0
 # define SOFTIRQ_VERBOSE       0
+# define RECLAIM_VERBOSE       0
 #endif
 
-#if VERBOSE || HARDIRQ_VERBOSE || SOFTIRQ_VERBOSE
+#if VERBOSE || HARDIRQ_VERBOSE || SOFTIRQ_VERBOSE || RECLAIM_VERBOSE
 /*
  * Quick filtering for interesting events:
  */
@@ -443,17 +446,18 @@ atomic_t nr_find_usage_backwards_recursions;
  * Locking printouts:
  */
 
+#define __USAGE(__STATE)                                               \
+       [LOCK_USED_IN_##__STATE] = "IN-"__stringify(__STATE)"-W",       \
+       [LOCK_ENABLED_##__STATE] = __stringify(__STATE)"-ON-W",         \
+       [LOCK_USED_IN_##__STATE##_READ] = "IN-"__stringify(__STATE)"-R",\
+       [LOCK_ENABLED_##__STATE##_READ] = __stringify(__STATE)"-ON-R",
+
 static const char *usage_str[] =
 {
-       [LOCK_USED] =                   "initial-use ",
-       [LOCK_USED_IN_HARDIRQ] =        "in-hardirq-W",
-       [LOCK_USED_IN_SOFTIRQ] =        "in-softirq-W",
-       [LOCK_ENABLED_SOFTIRQS] =       "softirq-on-W",
-       [LOCK_ENABLED_HARDIRQS] =       "hardirq-on-W",
-       [LOCK_USED_IN_HARDIRQ_READ] =   "in-hardirq-R",
-       [LOCK_USED_IN_SOFTIRQ_READ] =   "in-softirq-R",
-       [LOCK_ENABLED_SOFTIRQS_READ] =  "softirq-on-R",
-       [LOCK_ENABLED_HARDIRQS_READ] =  "hardirq-on-R",
+#define LOCKDEP_STATE(__STATE) __USAGE(__STATE)
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+       [LOCK_USED] = "INITIAL USE",
 };
 
 const char * __get_key_name(struct lockdep_subclass_key *key, char *str)
@@ -461,46 +465,45 @@ const char * __get_key_name(struct lockdep_subclass_key *key, char *str)
        return kallsyms_lookup((unsigned long)key, NULL, NULL, NULL, str);
 }
 
-void
-get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, char *c4)
+static inline unsigned long lock_flag(enum lock_usage_bit bit)
 {
-       *c1 = '.', *c2 = '.', *c3 = '.', *c4 = '.';
-
-       if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
-               *c1 = '+';
-       else
-               if (class->usage_mask & LOCKF_ENABLED_HARDIRQS)
-                       *c1 = '-';
+       return 1UL << bit;
+}
 
-       if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
-               *c2 = '+';
-       else
-               if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS)
-                       *c2 = '-';
+static char get_usage_char(struct lock_class *class, enum lock_usage_bit bit)
+{
+       char c = '.';
 
-       if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
-               *c3 = '-';
-       if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ) {
-               *c3 = '+';
-               if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
-                       *c3 = '?';
+       if (class->usage_mask & lock_flag(bit + 2))
+               c = '+';
+       if (class->usage_mask & lock_flag(bit)) {
+               c = '-';
+               if (class->usage_mask & lock_flag(bit + 2))
+                       c = '?';
        }
 
-       if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
-               *c4 = '-';
-       if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ) {
-               *c4 = '+';
-               if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
-                       *c4 = '?';
-       }
+       return c;
+}
+
+void get_usage_chars(struct lock_class *class, char usage[LOCK_USAGE_CHARS])
+{
+       int i = 0;
+
+#define LOCKDEP_STATE(__STATE)                                                 \
+       usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE);     \
+       usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE##_READ);
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+
+       usage[i] = '\0';
 }
 
 static void print_lock_name(struct lock_class *class)
 {
-       char str[KSYM_NAME_LEN], c1, c2, c3, c4;
+       char str[KSYM_NAME_LEN], usage[LOCK_USAGE_CHARS];
        const char *name;
 
-       get_usage_chars(class, &c1, &c2, &c3, &c4);
+       get_usage_chars(class, usage);
 
        name = class->name;
        if (!name) {
@@ -513,7 +516,7 @@ static void print_lock_name(struct lock_class *class)
                if (class->subclass)
                        printk("/%d", class->subclass);
        }
-       printk("){%c%c%c%c}", c1, c2, c3, c4);
+       printk("){%s}", usage);
 }
 
 static void print_lockdep_cache(struct lockdep_map *lock)
@@ -1263,9 +1266,49 @@ check_usage(struct task_struct *curr, struct held_lock *prev,
                        bit_backwards, bit_forwards, irqclass);
 }
 
-static int
-check_prev_add_irq(struct task_struct *curr, struct held_lock *prev,
-               struct held_lock *next)
+static const char *state_names[] = {
+#define LOCKDEP_STATE(__STATE) \
+       __stringify(__STATE),
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+};
+
+static const char *state_rnames[] = {
+#define LOCKDEP_STATE(__STATE) \
+       __stringify(__STATE)"-READ",
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+};
+
+static inline const char *state_name(enum lock_usage_bit bit)
+{
+       return (bit & 1) ? state_rnames[bit >> 2] : state_names[bit >> 2];
+}
+
+static int exclusive_bit(int new_bit)
+{
+       /*
+        * USED_IN
+        * USED_IN_READ
+        * ENABLED
+        * ENABLED_READ
+        *
+        * bit 0 - write/read
+        * bit 1 - used_in/enabled
+        * bit 2+  state
+        */
+
+       int state = new_bit & ~3;
+       int dir = new_bit & 2;
+
+       /*
+        * keep state, bit flip the direction and strip read.
+        */
+       return state | (dir ^ 2);
+}
+
+static int check_irq_usage(struct task_struct *curr, struct held_lock *prev,
+                          struct held_lock *next, enum lock_usage_bit bit)
 {
        /*
         * Prove that the new dependency does not connect a hardirq-safe
@@ -1273,38 +1316,34 @@ check_prev_add_irq(struct task_struct *curr, struct held_lock *prev,
         * the backwards-subgraph starting at <prev>, and the
         * forwards-subgraph starting at <next>:
         */
-       if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ,
-                                       LOCK_ENABLED_HARDIRQS, "hard"))
+       if (!check_usage(curr, prev, next, bit,
+                          exclusive_bit(bit), state_name(bit)))
                return 0;
 
+       bit++; /* _READ */
+
        /*
         * Prove that the new dependency does not connect a hardirq-safe-read
         * lock with a hardirq-unsafe lock - to achieve this we search
         * the backwards-subgraph starting at <prev>, and the
         * forwards-subgraph starting at <next>:
         */
-       if (!check_usage(curr, prev, next, LOCK_USED_IN_HARDIRQ_READ,
-                                       LOCK_ENABLED_HARDIRQS, "hard-read"))
+       if (!check_usage(curr, prev, next, bit,
+                          exclusive_bit(bit), state_name(bit)))
                return 0;
 
-       /*
-        * Prove that the new dependency does not connect a softirq-safe
-        * lock with a softirq-unsafe lock - to achieve this we search
-        * the backwards-subgraph starting at <prev>, and the
-        * forwards-subgraph starting at <next>:
-        */
-       if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ,
-                                       LOCK_ENABLED_SOFTIRQS, "soft"))
-               return 0;
-       /*
-        * Prove that the new dependency does not connect a softirq-safe-read
-        * lock with a softirq-unsafe lock - to achieve this we search
-        * the backwards-subgraph starting at <prev>, and the
-        * forwards-subgraph starting at <next>:
-        */
-       if (!check_usage(curr, prev, next, LOCK_USED_IN_SOFTIRQ_READ,
-                                       LOCK_ENABLED_SOFTIRQS, "soft"))
+       return 1;
+}
+
+static int
+check_prev_add_irq(struct task_struct *curr, struct held_lock *prev,
+               struct held_lock *next)
+{
+#define LOCKDEP_STATE(__STATE)                                         \
+       if (!check_irq_usage(curr, prev, next, LOCK_USED_IN_##__STATE)) \
                return 0;
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
 
        return 1;
 }
@@ -1933,7 +1972,7 @@ void print_irqtrace_events(struct task_struct *curr)
        print_ip_sym(curr->softirq_disable_ip);
 }
 
-static int hardirq_verbose(struct lock_class *class)
+static int HARDIRQ_verbose(struct lock_class *class)
 {
 #if HARDIRQ_VERBOSE
        return class_filter(class);
@@ -1941,7 +1980,7 @@ static int hardirq_verbose(struct lock_class *class)
        return 0;
 }
 
-static int softirq_verbose(struct lock_class *class)
+static int SOFTIRQ_verbose(struct lock_class *class)
 {
 #if SOFTIRQ_VERBOSE
        return class_filter(class);
@@ -1949,185 +1988,94 @@ static int softirq_verbose(struct lock_class *class)
        return 0;
 }
 
+static int RECLAIM_FS_verbose(struct lock_class *class)
+{
+#if RECLAIM_VERBOSE
+       return class_filter(class);
+#endif
+       return 0;
+}
+
 #define STRICT_READ_CHECKS     1
 
-static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
-               enum lock_usage_bit new_bit)
+static int (*state_verbose_f[])(struct lock_class *class) = {
+#define LOCKDEP_STATE(__STATE) \
+       __STATE##_verbose,
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+};
+
+static inline int state_verbose(enum lock_usage_bit bit,
+                               struct lock_class *class)
 {
-       int ret = 1;
+       return state_verbose_f[bit >> 2](class);
+}
 
-       switch(new_bit) {
-       case LOCK_USED_IN_HARDIRQ:
-               if (!valid_state(curr, this, new_bit, LOCK_ENABLED_HARDIRQS))
-                       return 0;
-               if (!valid_state(curr, this, new_bit,
-                                LOCK_ENABLED_HARDIRQS_READ))
-                       return 0;
-               /*
-                * just marked it hardirq-safe, check that this lock
-                * took no hardirq-unsafe lock in the past:
-                */
-               if (!check_usage_forwards(curr, this,
-                                         LOCK_ENABLED_HARDIRQS, "hard"))
-                       return 0;
-#if STRICT_READ_CHECKS
-               /*
-                * just marked it hardirq-safe, check that this lock
-                * took no hardirq-unsafe-read lock in the past:
-                */
-               if (!check_usage_forwards(curr, this,
-                               LOCK_ENABLED_HARDIRQS_READ, "hard-read"))
-                       return 0;
-#endif
-               if (hardirq_verbose(hlock_class(this)))
-                       ret = 2;
-               break;
-       case LOCK_USED_IN_SOFTIRQ:
-               if (!valid_state(curr, this, new_bit, LOCK_ENABLED_SOFTIRQS))
-                       return 0;
-               if (!valid_state(curr, this, new_bit,
-                                LOCK_ENABLED_SOFTIRQS_READ))
-                       return 0;
-               /*
-                * just marked it softirq-safe, check that this lock
-                * took no softirq-unsafe lock in the past:
-                */
-               if (!check_usage_forwards(curr, this,
-                                         LOCK_ENABLED_SOFTIRQS, "soft"))
-                       return 0;
-#if STRICT_READ_CHECKS
-               /*
-                * just marked it softirq-safe, check that this lock
-                * took no softirq-unsafe-read lock in the past:
-                */
-               if (!check_usage_forwards(curr, this,
-                               LOCK_ENABLED_SOFTIRQS_READ, "soft-read"))
-                       return 0;
-#endif
-               if (softirq_verbose(hlock_class(this)))
-                       ret = 2;
-               break;
-       case LOCK_USED_IN_HARDIRQ_READ:
-               if (!valid_state(curr, this, new_bit, LOCK_ENABLED_HARDIRQS))
-                       return 0;
-               /*
-                * just marked it hardirq-read-safe, check that this lock
-                * took no hardirq-unsafe lock in the past:
-                */
-               if (!check_usage_forwards(curr, this,
-                                         LOCK_ENABLED_HARDIRQS, "hard"))
-                       return 0;
-               if (hardirq_verbose(hlock_class(this)))
-                       ret = 2;
-               break;
-       case LOCK_USED_IN_SOFTIRQ_READ:
-               if (!valid_state(curr, this, new_bit, LOCK_ENABLED_SOFTIRQS))
-                       return 0;
-               /*
-                * just marked it softirq-read-safe, check that this lock
-                * took no softirq-unsafe lock in the past:
-                */
-               if (!check_usage_forwards(curr, this,
-                                         LOCK_ENABLED_SOFTIRQS, "soft"))
-                       return 0;
-               if (softirq_verbose(hlock_class(this)))
-                       ret = 2;
-               break;
-       case LOCK_ENABLED_HARDIRQS:
-               if (!valid_state(curr, this, new_bit, LOCK_USED_IN_HARDIRQ))
-                       return 0;
-               if (!valid_state(curr, this, new_bit,
-                                LOCK_USED_IN_HARDIRQ_READ))
-                       return 0;
-               /*
-                * just marked it hardirq-unsafe, check that no hardirq-safe
-                * lock in the system ever took it in the past:
-                */
-               if (!check_usage_backwards(curr, this,
-                                          LOCK_USED_IN_HARDIRQ, "hard"))
-                       return 0;
-#if STRICT_READ_CHECKS
-               /*
-                * just marked it hardirq-unsafe, check that no
-                * hardirq-safe-read lock in the system ever took
-                * it in the past:
-                */
-               if (!check_usage_backwards(curr, this,
-                                  LOCK_USED_IN_HARDIRQ_READ, "hard-read"))
-                       return 0;
-#endif
-               if (hardirq_verbose(hlock_class(this)))
-                       ret = 2;
-               break;
-       case LOCK_ENABLED_SOFTIRQS:
-               if (!valid_state(curr, this, new_bit, LOCK_USED_IN_SOFTIRQ))
-                       return 0;
-               if (!valid_state(curr, this, new_bit,
-                                LOCK_USED_IN_SOFTIRQ_READ))
-                       return 0;
-               /*
-                * just marked it softirq-unsafe, check that no softirq-safe
-                * lock in the system ever took it in the past:
-                */
-               if (!check_usage_backwards(curr, this,
-                                          LOCK_USED_IN_SOFTIRQ, "soft"))
-                       return 0;
-#if STRICT_READ_CHECKS
-               /*
-                * just marked it softirq-unsafe, check that no
-                * softirq-safe-read lock in the system ever took
-                * it in the past:
-                */
-               if (!check_usage_backwards(curr, this,
-                                  LOCK_USED_IN_SOFTIRQ_READ, "soft-read"))
-                       return 0;
-#endif
-               if (softirq_verbose(hlock_class(this)))
-                       ret = 2;
-               break;
-       case LOCK_ENABLED_HARDIRQS_READ:
-               if (!valid_state(curr, this, new_bit, LOCK_USED_IN_HARDIRQ))
-                       return 0;
-#if STRICT_READ_CHECKS
-               /*
-                * just marked it hardirq-read-unsafe, check that no
-                * hardirq-safe lock in the system ever took it in the past:
-                */
-               if (!check_usage_backwards(curr, this,
-                                          LOCK_USED_IN_HARDIRQ, "hard"))
-                       return 0;
-#endif
-               if (hardirq_verbose(hlock_class(this)))
-                       ret = 2;
-               break;
-       case LOCK_ENABLED_SOFTIRQS_READ:
-               if (!valid_state(curr, this, new_bit, LOCK_USED_IN_SOFTIRQ))
+typedef int (*check_usage_f)(struct task_struct *, struct held_lock *,
+                            enum lock_usage_bit bit, const char *name);
+
+static int
+mark_lock_irq(struct task_struct *curr, struct held_lock *this, int new_bit)
+{
+       int excl_bit = exclusive_bit(new_bit);
+       int read = new_bit & 1;
+       int dir = new_bit & 2;
+
+       /*
+        * mark USED_IN has to look forwards -- to ensure no dependency
+        * has ENABLED state, which would allow recursion deadlocks.
+        *
+        * mark ENABLED has to look backwards -- to ensure no dependee
+        * has USED_IN state, which, again, would allow  recursion deadlocks.
+        */
+       check_usage_f usage = dir ?
+               check_usage_backwards : check_usage_forwards;
+
+       /*
+        * Validate that this particular lock does not have conflicting
+        * usage states.
+        */
+       if (!valid_state(curr, this, new_bit, excl_bit))
+               return 0;
+
+       /*
+        * Validate that the lock dependencies don't have conflicting usage
+        * states.
+        */
+       if ((!read || !dir || STRICT_READ_CHECKS) &&
+                       !usage(curr, this, excl_bit, state_name(new_bit)))
+               return 0;
+
+       /*
+        * Check for read in write conflicts
+        */
+       if (!read) {
+               if (!valid_state(curr, this, new_bit, excl_bit + 1))
                        return 0;
-#if STRICT_READ_CHECKS
-               /*
-                * just marked it softirq-read-unsafe, check that no
-                * softirq-safe lock in the system ever took it in the past:
-                */
-               if (!check_usage_backwards(curr, this,
-                                          LOCK_USED_IN_SOFTIRQ, "soft"))
+
+               if (STRICT_READ_CHECKS &&
+                       !usage(curr, this, excl_bit + 1,
+                               state_name(new_bit + 1)))
                        return 0;
-#endif
-               if (softirq_verbose(hlock_class(this)))
-                       ret = 2;
-               break;
-       default:
-               WARN_ON(1);
-               break;
        }
 
-       return ret;
+       if (state_verbose(new_bit, hlock_class(this)))
+               return 2;
+
+       return 1;
 }
 
+enum mark_type {
+#define LOCKDEP_STATE(__STATE) __STATE,
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+};
+
 /*
  * Mark all held locks with a usage bit:
  */
 static int
-mark_held_locks(struct task_struct *curr, int hardirq)
+mark_held_locks(struct task_struct *curr, enum mark_type mark)
 {
        enum lock_usage_bit usage_bit;
        struct held_lock *hlock;
@@ -2136,17 +2084,12 @@ mark_held_locks(struct task_struct *curr, int hardirq)
        for (i = 0; i < curr->lockdep_depth; i++) {
                hlock = curr->held_locks + i;
 
-               if (hardirq) {
-                       if (hlock->read)
-                               usage_bit = LOCK_ENABLED_HARDIRQS_READ;
-                       else
-                               usage_bit = LOCK_ENABLED_HARDIRQS;
-               } else {
-                       if (hlock->read)
-                               usage_bit = LOCK_ENABLED_SOFTIRQS_READ;
-                       else
-                               usage_bit = LOCK_ENABLED_SOFTIRQS;
-               }
+               usage_bit = 2 + (mark << 2); /* ENABLED */
+               if (hlock->read)
+                       usage_bit += 1; /* READ */
+
+               BUG_ON(usage_bit >= LOCK_USAGE_STATES);
+
                if (!mark_lock(curr, hlock, usage_bit))
                        return 0;
        }
@@ -2200,7 +2143,7 @@ void trace_hardirqs_on_caller(unsigned long ip)
         * We are going to turn hardirqs on, so set the
         * usage bit for all held locks:
         */
-       if (!mark_held_locks(curr, 1))
+       if (!mark_held_locks(curr, HARDIRQ))
                return;
        /*
         * If we have softirqs enabled, then set the usage
@@ -2208,7 +2151,7 @@ void trace_hardirqs_on_caller(unsigned long ip)
         * this bit from being set before)
         */
        if (curr->softirqs_enabled)
-               if (!mark_held_locks(curr, 0))
+               if (!mark_held_locks(curr, SOFTIRQ))
                        return;
 
        curr->hardirq_enable_ip = ip;
@@ -2288,7 +2231,7 @@ void trace_softirqs_on(unsigned long ip)
         * enabled too:
         */
        if (curr->hardirqs_enabled)
-               mark_held_locks(curr, 0);
+               mark_held_locks(curr, SOFTIRQ);
 }
 
 /*
@@ -2317,6 +2260,48 @@ void trace_softirqs_off(unsigned long ip)
                debug_atomic_inc(&redundant_softirqs_off);
 }
 
+static void __lockdep_trace_alloc(gfp_t gfp_mask, unsigned long flags)
+{
+       struct task_struct *curr = current;
+
+       if (unlikely(!debug_locks))
+               return;
+
+       /* no reclaim without waiting on it */
+       if (!(gfp_mask & __GFP_WAIT))
+               return;
+
+       /* this guy won't enter reclaim */
+       if ((curr->flags & PF_MEMALLOC) && !(gfp_mask & __GFP_NOMEMALLOC))
+               return;
+
+       /* We're only interested __GFP_FS allocations for now */
+       if (!(gfp_mask & __GFP_FS))
+               return;
+
+       if (DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)))
+               return;
+
+       mark_held_locks(curr, RECLAIM_FS);
+}
+
+static void check_flags(unsigned long flags);
+
+void lockdep_trace_alloc(gfp_t gfp_mask)
+{
+       unsigned long flags;
+
+       if (unlikely(current->lockdep_recursion))
+               return;
+
+       raw_local_irq_save(flags);
+       check_flags(flags);
+       current->lockdep_recursion = 1;
+       __lockdep_trace_alloc(gfp_mask, flags);
+       current->lockdep_recursion = 0;
+       raw_local_irq_restore(flags);
+}
+
 static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock)
 {
        /*
@@ -2345,19 +2330,35 @@ static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock)
        if (!hlock->hardirqs_off) {
                if (hlock->read) {
                        if (!mark_lock(curr, hlock,
-                                       LOCK_ENABLED_HARDIRQS_READ))
+                                       LOCK_ENABLED_HARDIRQ_READ))
                                return 0;
                        if (curr->softirqs_enabled)
                                if (!mark_lock(curr, hlock,
-                                               LOCK_ENABLED_SOFTIRQS_READ))
+                                               LOCK_ENABLED_SOFTIRQ_READ))
                                        return 0;
                } else {
                        if (!mark_lock(curr, hlock,
-                                       LOCK_ENABLED_HARDIRQS))
+                                       LOCK_ENABLED_HARDIRQ))
                                return 0;
                        if (curr->softirqs_enabled)
                                if (!mark_lock(curr, hlock,
-                                               LOCK_ENABLED_SOFTIRQS))
+                                               LOCK_ENABLED_SOFTIRQ))
+                                       return 0;
+               }
+       }
+
+       /*
+        * We reuse the irq context infrastructure more broadly as a general
+        * context checking code. This tests GFP_FS recursion (a lock taken
+        * during reclaim for a GFP_FS allocation is held over a GFP_FS
+        * allocation).
+        */
+       if (!hlock->trylock && (curr->lockdep_reclaim_gfp & __GFP_FS)) {
+               if (hlock->read) {
+                       if (!mark_lock(curr, hlock, LOCK_USED_IN_RECLAIM_FS_READ))
+                                       return 0;
+               } else {
+                       if (!mark_lock(curr, hlock, LOCK_USED_IN_RECLAIM_FS))
                                        return 0;
                }
        }
@@ -2412,6 +2413,10 @@ static inline int separate_irq_context(struct task_struct *curr,
        return 0;
 }
 
+void lockdep_trace_alloc(gfp_t gfp_mask)
+{
+}
+
 #endif
 
 /*
@@ -2445,14 +2450,13 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
                return 0;
 
        switch (new_bit) {
-       case LOCK_USED_IN_HARDIRQ:
-       case LOCK_USED_IN_SOFTIRQ:
-       case LOCK_USED_IN_HARDIRQ_READ:
-       case LOCK_USED_IN_SOFTIRQ_READ:
-       case LOCK_ENABLED_HARDIRQS:
-       case LOCK_ENABLED_SOFTIRQS:
-       case LOCK_ENABLED_HARDIRQS_READ:
-       case LOCK_ENABLED_SOFTIRQS_READ:
+#define LOCKDEP_STATE(__STATE)                 \
+       case LOCK_USED_IN_##__STATE:            \
+       case LOCK_USED_IN_##__STATE##_READ:     \
+       case LOCK_ENABLED_##__STATE:            \
+       case LOCK_ENABLED_##__STATE##_READ:
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
                ret = mark_lock_irq(curr, this, new_bit);
                if (!ret)
                        return 0;
@@ -2966,6 +2970,16 @@ void lock_release(struct lockdep_map *lock, int nested,
 }
 EXPORT_SYMBOL_GPL(lock_release);
 
+void lockdep_set_current_reclaim_state(gfp_t gfp_mask)
+{
+       current->lockdep_reclaim_gfp = gfp_mask;
+}
+
+void lockdep_clear_current_reclaim_state(void)
+{
+       current->lockdep_reclaim_gfp = 0;
+}
+
 #ifdef CONFIG_LOCK_STAT
 static int
 print_lock_contention_bug(struct task_struct *curr, struct lockdep_map *lock,
index 56b196932c081e915568d4fef27a92c08e129758..a2cc7e9a6e841b9e955709b9139cd96b3d803f2e 100644 (file)
@@ -6,6 +6,45 @@
  * lockdep subsystem internal functions and variables.
  */
 
+/*
+ * Lock-class usage-state bits:
+ */
+enum lock_usage_bit {
+#define LOCKDEP_STATE(__STATE)         \
+       LOCK_USED_IN_##__STATE,         \
+       LOCK_USED_IN_##__STATE##_READ,  \
+       LOCK_ENABLED_##__STATE,         \
+       LOCK_ENABLED_##__STATE##_READ,
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+       LOCK_USED,
+       LOCK_USAGE_STATES
+};
+
+/*
+ * Usage-state bitmasks:
+ */
+#define __LOCKF(__STATE)       LOCKF_##__STATE = (1 << LOCK_##__STATE),
+
+enum {
+#define LOCKDEP_STATE(__STATE)                                         \
+       __LOCKF(USED_IN_##__STATE)                                      \
+       __LOCKF(USED_IN_##__STATE##_READ)                               \
+       __LOCKF(ENABLED_##__STATE)                                      \
+       __LOCKF(ENABLED_##__STATE##_READ)
+#include "lockdep_states.h"
+#undef LOCKDEP_STATE
+       __LOCKF(USED)
+};
+
+#define LOCKF_ENABLED_IRQ (LOCKF_ENABLED_HARDIRQ | LOCKF_ENABLED_SOFTIRQ)
+#define LOCKF_USED_IN_IRQ (LOCKF_USED_IN_HARDIRQ | LOCKF_USED_IN_SOFTIRQ)
+
+#define LOCKF_ENABLED_IRQ_READ \
+               (LOCKF_ENABLED_HARDIRQ_READ | LOCKF_ENABLED_SOFTIRQ_READ)
+#define LOCKF_USED_IN_IRQ_READ \
+               (LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)
+
 /*
  * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
  * we track.
 extern struct list_head all_lock_classes;
 extern struct lock_chain lock_chains[];
 
-extern void
-get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, char *c4);
+#define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2)
+
+extern void get_usage_chars(struct lock_class *class,
+                           char usage[LOCK_USAGE_CHARS]);
 
 extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str);
 
index 13716b8138961ee9f5feffe23ad9115fc27766e3..d7135aa2d2c4ccc0f3638cfa6fb3b2742e33c43c 100644 (file)
@@ -84,7 +84,7 @@ static int l_show(struct seq_file *m, void *v)
 {
        struct lock_class *class = v;
        struct lock_list *entry;
-       char c1, c2, c3, c4;
+       char usage[LOCK_USAGE_CHARS];
 
        if (v == SEQ_START_TOKEN) {
                seq_printf(m, "all lock classes:\n");
@@ -100,8 +100,8 @@ static int l_show(struct seq_file *m, void *v)
        seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class));
 #endif
 
-       get_usage_chars(class, &c1, &c2, &c3, &c4);
-       seq_printf(m, " %c%c%c%c", c1, c2, c3, c4);
+       get_usage_chars(class, usage);
+       seq_printf(m, " %s", usage);
 
        seq_printf(m, ": ");
        print_name(m, class);
@@ -300,27 +300,27 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
                        nr_uncategorized++;
                if (class->usage_mask & LOCKF_USED_IN_IRQ)
                        nr_irq_safe++;
-               if (class->usage_mask & LOCKF_ENABLED_IRQS)
+               if (class->usage_mask & LOCKF_ENABLED_IRQ)
                        nr_irq_unsafe++;
                if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
                        nr_softirq_safe++;
-               if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS)
+               if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ)
                        nr_softirq_unsafe++;
                if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
                        nr_hardirq_safe++;
-               if (class->usage_mask & LOCKF_ENABLED_HARDIRQS)
+               if (class->usage_mask & LOCKF_ENABLED_HARDIRQ)
                        nr_hardirq_unsafe++;
                if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)
                        nr_irq_read_safe++;
-               if (class->usage_mask & LOCKF_ENABLED_IRQS_READ)
+               if (class->usage_mask & LOCKF_ENABLED_IRQ_READ)
                        nr_irq_read_unsafe++;
                if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)
                        nr_softirq_read_safe++;
-               if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
+               if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_READ)
                        nr_softirq_read_unsafe++;
                if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)
                        nr_hardirq_read_safe++;
-               if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
+               if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ)
                        nr_hardirq_read_unsafe++;
 
 #ifdef CONFIG_PROVE_LOCKING
@@ -601,6 +601,10 @@ static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
 static void seq_header(struct seq_file *m)
 {
        seq_printf(m, "lock_stat version 0.3\n");
+
+       if (unlikely(!debug_locks))
+               seq_printf(m, "*WARNING* lock debugging disabled!! - possibly due to a lockdep warning\n");
+
        seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
        seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
                        "%14s %14s\n",
diff --git a/kernel/lockdep_states.h b/kernel/lockdep_states.h
new file mode 100644 (file)
index 0000000..995b0cc
--- /dev/null
@@ -0,0 +1,9 @@
+/*
+ * Lockdep states,
+ *
+ * please update XXX_LOCK_USAGE_STATES in include/linux/lockdep.h whenever
+ * you add one, or come up with a nice dynamic solution.
+ */
+LOCKDEP_STATE(HARDIRQ)
+LOCKDEP_STATE(SOFTIRQ)
+LOCKDEP_STATE(RECLAIM_FS)
index 1d94160eb5326e94c0222da947b8c1ee4ee44875..50d022e5a5606dd64d985afbff9d33621f06ab96 100644 (file)
 /*
  * Must be called with lock->wait_lock held.
  */
-void debug_mutex_set_owner(struct mutex *lock, struct thread_info *new_owner)
-{
-       lock->owner = new_owner;
-}
-
 void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
 {
        memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
@@ -59,7 +54,6 @@ void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
 
        /* Mark the current thread as blocked on the lock: */
        ti->task->blocked_on = waiter;
-       waiter->lock = lock;
 }
 
 void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
@@ -82,7 +76,7 @@ void debug_mutex_unlock(struct mutex *lock)
        DEBUG_LOCKS_WARN_ON(lock->magic != lock);
        DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
        DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
-       DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
+       mutex_clear_owner(lock);
 }
 
 void debug_mutex_init(struct mutex *lock, const char *name,
@@ -95,7 +89,6 @@ void debug_mutex_init(struct mutex *lock, const char *name,
        debug_check_no_locks_freed((void *)lock, sizeof(*lock));
        lockdep_init_map(&lock->dep_map, name, key, 0);
 #endif
-       lock->owner = NULL;
        lock->magic = lock;
 }
 
index babfbdfc534b7127e3769405433499f1929a44a5..6b2d735846a56f17425749b6501fe2023c0e6cdb 100644 (file)
 /*
  * This must be called with lock->wait_lock held.
  */
-extern void
-debug_mutex_set_owner(struct mutex *lock, struct thread_info *new_owner);
-
-static inline void debug_mutex_clear_owner(struct mutex *lock)
-{
-       lock->owner = NULL;
-}
-
 extern void debug_mutex_lock_common(struct mutex *lock,
                                    struct mutex_waiter *waiter);
 extern void debug_mutex_wake_waiter(struct mutex *lock,
@@ -35,6 +27,16 @@ extern void debug_mutex_unlock(struct mutex *lock);
 extern void debug_mutex_init(struct mutex *lock, const char *name,
                             struct lock_class_key *key);
 
+static inline void mutex_set_owner(struct mutex *lock)
+{
+       lock->owner = current_thread_info();
+}
+
+static inline void mutex_clear_owner(struct mutex *lock)
+{
+       lock->owner = NULL;
+}
+
 #define spin_lock_mutex(lock, flags)                   \
        do {                                            \
                struct mutex *l = container_of(lock, struct mutex, wait_lock); \
index 4f45d4b658ef6ab1fda9357725b01361a6768a76..5d79781394a306e75048668262a6c3f49f5321ef 100644 (file)
  * Many thanks to Arjan van de Ven, Thomas Gleixner, Steven Rostedt and
  * David Howells for suggestions and improvements.
  *
+ *  - Adaptive spinning for mutexes by Peter Zijlstra. (Ported to mainline
+ *    from the -rt tree, where it was originally implemented for rtmutexes
+ *    by Steven Rostedt, based on work by Gregory Haskins, Peter Morreale
+ *    and Sven Dietrich.
+ *
  * Also see Documentation/mutex-design.txt.
  */
 #include <linux/mutex.h>
@@ -46,6 +51,7 @@ __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key)
        atomic_set(&lock->count, 1);
        spin_lock_init(&lock->wait_lock);
        INIT_LIST_HEAD(&lock->wait_list);
+       mutex_clear_owner(lock);
 
        debug_mutex_init(lock, name, key);
 }
@@ -91,6 +97,7 @@ void inline __sched mutex_lock(struct mutex *lock)
         * 'unlocked' into 'locked' state.
         */
        __mutex_fastpath_lock(&lock->count, __mutex_lock_slowpath);
+       mutex_set_owner(lock);
 }
 
 EXPORT_SYMBOL(mutex_lock);
@@ -115,6 +122,14 @@ void __sched mutex_unlock(struct mutex *lock)
         * The unlocking fastpath is the 0->1 transition from 'locked'
         * into 'unlocked' state:
         */
+#ifndef CONFIG_DEBUG_MUTEXES
+       /*
+        * When debugging is enabled we must not clear the owner before time,
+        * the slow path will always be taken, and that clears the owner field
+        * after verifying that it was indeed current.
+        */
+       mutex_clear_owner(lock);
+#endif
        __mutex_fastpath_unlock(&lock->count, __mutex_unlock_slowpath);
 }
 
@@ -129,21 +144,75 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 {
        struct task_struct *task = current;
        struct mutex_waiter waiter;
-       unsigned int old_val;
        unsigned long flags;
 
+       preempt_disable();
+       mutex_acquire(&lock->dep_map, subclass, 0, ip);
+#if defined(CONFIG_SMP) && !defined(CONFIG_DEBUG_MUTEXES)
+       /*
+        * Optimistic spinning.
+        *
+        * We try to spin for acquisition when we find that there are no
+        * pending waiters and the lock owner is currently running on a
+        * (different) CPU.
+        *
+        * The rationale is that if the lock owner is running, it is likely to
+        * release the lock soon.
+        *
+        * Since this needs the lock owner, and this mutex implementation
+        * doesn't track the owner atomically in the lock field, we need to
+        * track it non-atomically.
+        *
+        * We can't do this for DEBUG_MUTEXES because that relies on wait_lock
+        * to serialize everything.
+        */
+
+       for (;;) {
+               struct thread_info *owner;
+
+               /*
+                * If there's an owner, wait for it to either
+                * release the lock or go to sleep.
+                */
+               owner = ACCESS_ONCE(lock->owner);
+               if (owner && !mutex_spin_on_owner(lock, owner))
+                       break;
+
+               if (atomic_cmpxchg(&lock->count, 1, 0) == 1) {
+                       lock_acquired(&lock->dep_map, ip);
+                       mutex_set_owner(lock);
+                       preempt_enable();
+                       return 0;
+               }
+
+               /*
+                * When there's no owner, we might have preempted between the
+                * owner acquiring the lock and setting the owner field. If
+                * we're an RT task that will live-lock because we won't let
+                * the owner complete.
+                */
+               if (!owner && (need_resched() || rt_task(task)))
+                       break;
+
+               /*
+                * The cpu_relax() call is a compiler barrier which forces
+                * everything in this loop to be re-loaded. We don't need
+                * memory barriers as we'll eventually observe the right
+                * values at the cost of a few extra spins.
+                */
+               cpu_relax();
+       }
+#endif
        spin_lock_mutex(&lock->wait_lock, flags);
 
        debug_mutex_lock_common(lock, &waiter);
-       mutex_acquire(&lock->dep_map, subclass, 0, ip);
        debug_mutex_add_waiter(lock, &waiter, task_thread_info(task));
 
        /* add waiting tasks to the end of the waitqueue (FIFO): */
        list_add_tail(&waiter.list, &lock->wait_list);
        waiter.task = task;
 
-       old_val = atomic_xchg(&lock->count, -1);
-       if (old_val == 1)
+       if (atomic_xchg(&lock->count, -1) == 1)
                goto done;
 
        lock_contended(&lock->dep_map, ip);
@@ -158,8 +227,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
                 * that when we release the lock, we properly wake up the
                 * other waiters:
                 */
-               old_val = atomic_xchg(&lock->count, -1);
-               if (old_val == 1)
+               if (atomic_xchg(&lock->count, -1) == 1)
                        break;
 
                /*
@@ -173,21 +241,22 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
                        spin_unlock_mutex(&lock->wait_lock, flags);
 
                        debug_mutex_free_waiter(&waiter);
+                       preempt_enable();
                        return -EINTR;
                }
                __set_task_state(task, state);
 
                /* didnt get the lock, go to sleep: */
                spin_unlock_mutex(&lock->wait_lock, flags);
-               schedule();
+               __schedule();
                spin_lock_mutex(&lock->wait_lock, flags);
        }
 
 done:
        lock_acquired(&lock->dep_map, ip);
        /* got the lock - rejoice! */
-       mutex_remove_waiter(lock, &waiter, task_thread_info(task));
-       debug_mutex_set_owner(lock, task_thread_info(task));
+       mutex_remove_waiter(lock, &waiter, current_thread_info());
+       mutex_set_owner(lock);
 
        /* set it to 0 if there are no waiters left: */
        if (likely(list_empty(&lock->wait_list)))
@@ -196,6 +265,7 @@ done:
        spin_unlock_mutex(&lock->wait_lock, flags);
 
        debug_mutex_free_waiter(&waiter);
+       preempt_enable();
 
        return 0;
 }
@@ -222,7 +292,8 @@ int __sched
 mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass)
 {
        might_sleep();
-       return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, subclass, _RET_IP_);
+       return __mutex_lock_common(lock, TASK_INTERRUPTIBLE,
+                                  subclass, _RET_IP_);
 }
 
 EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested);
@@ -260,8 +331,6 @@ __mutex_unlock_common_slowpath(atomic_t *lock_count, int nested)
                wake_up_process(waiter->task);
        }
 
-       debug_mutex_clear_owner(lock);
-
        spin_unlock_mutex(&lock->wait_lock, flags);
 }
 
@@ -298,18 +367,30 @@ __mutex_lock_interruptible_slowpath(atomic_t *lock_count);
  */
 int __sched mutex_lock_interruptible(struct mutex *lock)
 {
+       int ret;
+
        might_sleep();
-       return __mutex_fastpath_lock_retval
+       ret =  __mutex_fastpath_lock_retval
                        (&lock->count, __mutex_lock_interruptible_slowpath);
+       if (!ret)
+               mutex_set_owner(lock);
+
+       return ret;
 }
 
 EXPORT_SYMBOL(mutex_lock_interruptible);
 
 int __sched mutex_lock_killable(struct mutex *lock)
 {
+       int ret;
+
        might_sleep();
-       return __mutex_fastpath_lock_retval
+       ret = __mutex_fastpath_lock_retval
                        (&lock->count, __mutex_lock_killable_slowpath);
+       if (!ret)
+               mutex_set_owner(lock);
+
+       return ret;
 }
 EXPORT_SYMBOL(mutex_lock_killable);
 
@@ -352,9 +433,10 @@ static inline int __mutex_trylock_slowpath(atomic_t *lock_count)
 
        prev = atomic_xchg(&lock->count, -1);
        if (likely(prev == 1)) {
-               debug_mutex_set_owner(lock, current_thread_info());
+               mutex_set_owner(lock);
                mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
        }
+
        /* Set it back to 0 if there are no waiters: */
        if (likely(list_empty(&lock->wait_list)))
                atomic_set(&lock->count, 0);
@@ -380,8 +462,13 @@ static inline int __mutex_trylock_slowpath(atomic_t *lock_count)
  */
 int __sched mutex_trylock(struct mutex *lock)
 {
-       return __mutex_fastpath_trylock(&lock->count,
-                                       __mutex_trylock_slowpath);
+       int ret;
+
+       ret = __mutex_fastpath_trylock(&lock->count, __mutex_trylock_slowpath);
+       if (ret)
+               mutex_set_owner(lock);
+
+       return ret;
 }
 
 EXPORT_SYMBOL(mutex_trylock);
index a075dafbb290c18bdf8972c361d8063f2478fa69..67578ca48f94e1dad6f7cf3760c28d20a86605e2 100644 (file)
 #define mutex_remove_waiter(lock, waiter, ti) \
                __list_del((waiter)->list.prev, (waiter)->list.next)
 
-#define debug_mutex_set_owner(lock, new_owner)         do { } while (0)
-#define debug_mutex_clear_owner(lock)                  do { } while (0)
+#ifdef CONFIG_SMP
+static inline void mutex_set_owner(struct mutex *lock)
+{
+       lock->owner = current_thread_info();
+}
+
+static inline void mutex_clear_owner(struct mutex *lock)
+{
+       lock->owner = NULL;
+}
+#else
+static inline void mutex_set_owner(struct mutex *lock)
+{
+}
+
+static inline void mutex_clear_owner(struct mutex *lock)
+{
+}
+#endif
+
 #define debug_mutex_wake_waiter(lock, waiter)          do { } while (0)
 #define debug_mutex_free_waiter(waiter)                        do { } while (0)
 #define debug_mutex_add_waiter(lock, waiter, ti)       do { } while (0)
index 5757e03cfac0bdf7cd50f3625a318645c562b973..196d48babbef87c088214e4f252b4397d2bf25be 100644 (file)
@@ -4942,15 +4942,13 @@ pick_next_task(struct rq *rq)
 /*
  * schedule() is the main scheduler function.
  */
-asmlinkage void __sched schedule(void)
+asmlinkage void __sched __schedule(void)
 {
        struct task_struct *prev, *next;
        unsigned long *switch_count;
        struct rq *rq;
        int cpu;
 
-need_resched:
-       preempt_disable();
        cpu = smp_processor_id();
        rq = cpu_rq(cpu);
        rcu_qsctr_inc(cpu);
@@ -5007,13 +5005,80 @@ need_resched_nonpreemptible:
 
        if (unlikely(reacquire_kernel_lock(current) < 0))
                goto need_resched_nonpreemptible;
+}
 
+asmlinkage void __sched schedule(void)
+{
+need_resched:
+       preempt_disable();
+       __schedule();
        preempt_enable_no_resched();
        if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
                goto need_resched;
 }
 EXPORT_SYMBOL(schedule);
 
+#ifdef CONFIG_SMP
+/*
+ * Look out! "owner" is an entirely speculative pointer
+ * access and not reliable.
+ */
+int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner)
+{
+       unsigned int cpu;
+       struct rq *rq;
+
+       if (!sched_feat(OWNER_SPIN))
+               return 0;
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+       /*
+        * Need to access the cpu field knowing that
+        * DEBUG_PAGEALLOC could have unmapped it if
+        * the mutex owner just released it and exited.
+        */
+       if (probe_kernel_address(&owner->cpu, cpu))
+               goto out;
+#else
+       cpu = owner->cpu;
+#endif
+
+       /*
+        * Even if the access succeeded (likely case),
+        * the cpu field may no longer be valid.
+        */
+       if (cpu >= nr_cpumask_bits)
+               goto out;
+
+       /*
+        * We need to validate that we can do a
+        * get_cpu() and that we have the percpu area.
+        */
+       if (!cpu_online(cpu))
+               goto out;
+
+       rq = cpu_rq(cpu);
+
+       for (;;) {
+               /*
+                * Owner changed, break to re-assess state.
+                */
+               if (lock->owner != owner)
+                       break;
+
+               /*
+                * Is that owner really running on that cpu?
+                */
+               if (task_thread_info(rq->curr) != owner || need_resched())
+                       return 0;
+
+               cpu_relax();
+       }
+out:
+       return 1;
+}
+#endif
+
 #ifdef CONFIG_PREEMPT
 /*
  * this is the entry point to schedule() from in-kernel preemption
index 76f61756e677647dda4ae01ede5ac942329a09c8..4569bfa7df9b9fee6f057e22aca18299d3c45f3b 100644 (file)
@@ -14,3 +14,4 @@ SCHED_FEAT(LB_WAKEUP_UPDATE, 1)
 SCHED_FEAT(ASYM_EFF_LOAD, 1)
 SCHED_FEAT(WAKEUP_OVERLAP, 0)
 SCHED_FEAT(LAST_BUDDY, 1)
+SCHED_FEAT(OWNER_SPIN, 1)
index 9b77fc9a9ac8286074b1784771dac7c0eb2a08e2..b4555568b4e4ad16f34a887eabed6f21e05abfba 100644 (file)
@@ -491,14 +491,18 @@ static inline void debug_timer_free(struct timer_list *timer)
        debug_object_free(timer, &timer_debug_descr);
 }
 
-static void __init_timer(struct timer_list *timer);
+static void __init_timer(struct timer_list *timer,
+                        const char *name,
+                        struct lock_class_key *key);
 
-void init_timer_on_stack(struct timer_list *timer)
+void init_timer_on_stack_key(struct timer_list *timer,
+                            const char *name,
+                            struct lock_class_key *key)
 {
        debug_object_init_on_stack(timer, &timer_debug_descr);
-       __init_timer(timer);
+       __init_timer(timer, name, key);
 }
-EXPORT_SYMBOL_GPL(init_timer_on_stack);
+EXPORT_SYMBOL_GPL(init_timer_on_stack_key);
 
 void destroy_timer_on_stack(struct timer_list *timer)
 {
@@ -512,7 +516,9 @@ static inline void debug_timer_activate(struct timer_list *timer) { }
 static inline void debug_timer_deactivate(struct timer_list *timer) { }
 #endif
 
-static void __init_timer(struct timer_list *timer)
+static void __init_timer(struct timer_list *timer,
+                        const char *name,
+                        struct lock_class_key *key)
 {
        timer->entry.next = NULL;
        timer->base = __raw_get_cpu_var(tvec_bases);
@@ -521,6 +527,7 @@ static void __init_timer(struct timer_list *timer)
        timer->start_pid = -1;
        memset(timer->start_comm, 0, TASK_COMM_LEN);
 #endif
+       lockdep_init_map(&timer->lockdep_map, name, key, 0);
 }
 
 /**
@@ -530,19 +537,23 @@ static void __init_timer(struct timer_list *timer)
  * init_timer() must be done to a timer prior calling *any* of the
  * other timer functions.
  */
-void init_timer(struct timer_list *timer)
+void init_timer_key(struct timer_list *timer,
+                   const char *name,
+                   struct lock_class_key *key)
 {
        debug_timer_init(timer);
-       __init_timer(timer);
+       __init_timer(timer, name, key);
 }
-EXPORT_SYMBOL(init_timer);
+EXPORT_SYMBOL(init_timer_key);
 
-void init_timer_deferrable(struct timer_list *timer)
+void init_timer_deferrable_key(struct timer_list *timer,
+                              const char *name,
+                              struct lock_class_key *key)
 {
-       init_timer(timer);
+       init_timer_key(timer, name, key);
        timer_set_deferrable(timer);
 }
-EXPORT_SYMBOL(init_timer_deferrable);
+EXPORT_SYMBOL(init_timer_deferrable_key);
 
 static inline void detach_timer(struct timer_list *timer,
                                int clear_pending)
@@ -826,6 +837,15 @@ EXPORT_SYMBOL(try_to_del_timer_sync);
  */
 int del_timer_sync(struct timer_list *timer)
 {
+#ifdef CONFIG_LOCKDEP
+       unsigned long flags;
+
+       local_irq_save(flags);
+       lock_map_acquire(&timer->lockdep_map);
+       lock_map_release(&timer->lockdep_map);
+       local_irq_restore(flags);
+#endif
+
        for (;;) {
                int ret = try_to_del_timer_sync(timer);
                if (ret >= 0)
@@ -897,10 +917,36 @@ static inline void __run_timers(struct tvec_base *base)
 
                        set_running_timer(base, timer);
                        detach_timer(timer, 1);
+
                        spin_unlock_irq(&base->lock);
                        {
                                int preempt_count = preempt_count();
+
+#ifdef CONFIG_LOCKDEP
+                               /*
+                                * It is permissible to free the timer from
+                                * inside the function that is called from
+                                * it, this we need to take into account for
+                                * lockdep too. To avoid bogus "held lock
+                                * freed" warnings as well as problems when
+                                * looking into timer->lockdep_map, make a
+                                * copy and use that here.
+                                */
+                               struct lockdep_map lockdep_map =
+                                       timer->lockdep_map;
+#endif
+                               /*
+                                * Couple the lock chain with the lock chain at
+                                * del_timer_sync() by acquiring the lock_map
+                                * around the fn() call here and in
+                                * del_timer_sync().
+                                */
+                               lock_map_acquire(&lockdep_map);
+
                                fn(data);
+
+                               lock_map_release(&lockdep_map);
+
                                if (preempt_count != preempt_count()) {
                                        printk(KERN_ERR "huh, entered %p "
                                               "with preempt_count %08x, exited"
index 5c44ed49ca93c5a1d7a39f5570b0d1254a45de80..a3803ea8c27d5aaaccb5bd2d1f8141786dc9cc27 100644 (file)
@@ -1479,6 +1479,8 @@ __alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
        unsigned long did_some_progress;
        unsigned long pages_reclaimed = 0;
 
+       lockdep_trace_alloc(gfp_mask);
+
        might_sleep_if(wait);
 
        if (should_fail_alloc_page(gfp_mask, order))
@@ -1578,12 +1580,15 @@ nofail_alloc:
         */
        cpuset_update_task_memory_state();
        p->flags |= PF_MEMALLOC;
+
+       lockdep_set_current_reclaim_state(gfp_mask);
        reclaim_state.reclaimed_slab = 0;
        p->reclaim_state = &reclaim_state;
 
        did_some_progress = try_to_free_pages(zonelist, order, gfp_mask);
 
        p->reclaim_state = NULL;
+       lockdep_clear_current_reclaim_state();
        p->flags &= ~PF_MEMALLOC;
 
        cond_resched();
index 4d00855629c4921e3c590406335549683e6c6daf..825c606f691d11bfb3372627aff50f115358aff3 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3318,6 +3318,8 @@ __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
        unsigned long save_flags;
        void *ptr;
 
+       lockdep_trace_alloc(flags);
+
        if (slab_should_failslab(cachep, flags))
                return NULL;
 
@@ -3394,6 +3396,8 @@ __cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller)
        unsigned long save_flags;
        void *objp;
 
+       lockdep_trace_alloc(flags);
+
        if (slab_should_failslab(cachep, flags))
                return NULL;
 
index 0bfa680a8981127307d1d922231dca3d66f9b2bd..7a3411524dacd555e9ce70e287a4232072391e10 100644 (file)
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -475,6 +475,8 @@ void *__kmalloc_node(size_t size, gfp_t gfp, int node)
        unsigned int *m;
        int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
 
+       lockdep_trace_alloc(gfp);
+
        if (size < PAGE_SIZE - align) {
                if (!size)
                        return ZERO_SIZE_PTR;
index c65a4edafc3343e83a2513f8edab9b0ed82f3ab5..c4ea9158c9fbd0e4630062aa0098406000be45c3 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1590,6 +1590,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
        unsigned long flags;
        unsigned int objsize;
 
+       lockdep_trace_alloc(gfpflags);
        might_sleep_if(gfpflags & __GFP_WAIT);
 
        if (should_failslab(s->objsize, gfpflags))
index 56ddf41149eb77a55158ced628c02f817b990618..479e46719394cceccad44d55c28db3e2942616e7 100644 (file)
@@ -1965,6 +1965,8 @@ static int kswapd(void *p)
        };
        node_to_cpumask_ptr(cpumask, pgdat->node_id);
 
+       lockdep_set_current_reclaim_state(GFP_KERNEL);
+
        if (!cpumask_empty(cpumask))
                set_cpus_allowed_ptr(tsk, cpumask);
        current->reclaim_state = &reclaim_state;