From f9829cceb686f3719215fe43c8593e5f3efe1710 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Mon, 10 Jul 2006 04:44:01 -0700 Subject: [PATCH] Minor cleanup to lockdep.c - Use printk formatting for indentation - Don't leave NTFS in the default event filter Signed-off-by: Andi Kleen Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/lockdep.c | 44 ++++++++++++-------------------------------- 1 file changed, 12 insertions(+), 32 deletions(-) (limited to 'kernel/lockdep.c') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index f32ca78c198..42af5cc31a4 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -169,22 +169,17 @@ EXPORT_SYMBOL(lockdep_internal); */ static int class_filter(struct lock_class *class) { +#if 0 + /* Example */ if (class->name_version == 1 && - !strcmp(class->name, "&rl->lock")) + !strcmp(class->name, "lockname")) return 1; if (class->name_version == 1 && - !strcmp(class->name, "&ni->mrec_lock")) + !strcmp(class->name, "&struct->lockfield")) return 1; - if (class->name_version == 1 && - !strcmp(class->name, "mft_ni_runlist_lock")) - return 1; - if (class->name_version == 1 && - !strcmp(class->name, "mft_ni_mrec_lock")) - return 1; - if (class->name_version == 1 && - !strcmp(class->name, "&vol->lcnbmp_lock")) - return 1; - return 0; +#endif + /* Allow everything else. 0 would be filter everything else */ + return 1; } #endif @@ -408,23 +403,12 @@ static void lockdep_print_held_locks(struct task_struct *curr) print_lock(curr->held_locks + i); } } -/* - * Helper to print a nice hierarchy of lock dependencies: - */ -static void print_spaces(int nr) -{ - int i; - - for (i = 0; i < nr; i++) - printk(" "); -} static void print_lock_class_header(struct lock_class *class, int depth) { int bit; - print_spaces(depth); - printk("->"); + printk("%*s->", depth, ""); print_lock_name(class); printk(" ops: %lu", class->ops); printk(" {\n"); @@ -433,17 +417,14 @@ static void print_lock_class_header(struct lock_class *class, int depth) if (class->usage_mask & (1 << bit)) { int len = depth; - print_spaces(depth); - len += printk(" %s", usage_str[bit]); + len += printk("%*s %s", depth, "", usage_str[bit]); len += printk(" at:\n"); print_stack_trace(class->usage_traces + bit, len); } } - print_spaces(depth); - printk(" }\n"); + printk("%*s }\n", depth, ""); - print_spaces(depth); - printk(" ... key at: "); + printk("%*s ... key at: ",depth,""); print_ip_sym((unsigned long)class->key); } @@ -463,8 +444,7 @@ static void print_lock_dependencies(struct lock_class *class, int depth) DEBUG_LOCKS_WARN_ON(!entry->class); print_lock_dependencies(entry->class, depth + 1); - print_spaces(depth); - printk(" ... acquired at:\n"); + printk("%*s ... acquired at:\n",depth,""); print_stack_trace(&entry->trace, 2); printk("\n"); } -- cgit v1.2.3 From 55794a412fdf9af1744800e5020a4ec6b21e3cdc Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Mon, 10 Jul 2006 04:44:03 -0700 Subject: [PATCH] lockdep: improve debug output Make lockdep print which lock is held, in the "kfree() of a live lock" scenario. Signed-off-by: Arjan van de Ven Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/lockdep.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'kernel/lockdep.c') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 42af5cc31a4..c1f34addd00 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -2551,7 +2551,7 @@ static inline int in_range(const void *start, const void *addr, const void *end) static void print_freed_lock_bug(struct task_struct *curr, const void *mem_from, - const void *mem_to) + const void *mem_to, struct held_lock *hlock) { if (!debug_locks_off()) return; @@ -2563,6 +2563,7 @@ print_freed_lock_bug(struct task_struct *curr, const void *mem_from, printk( "-------------------------\n"); printk("%s/%d is freeing memory %p-%p, with a lock still held there!\n", curr->comm, curr->pid, mem_from, mem_to-1); + print_lock(hlock); lockdep_print_held_locks(curr); printk("\nstack backtrace:\n"); @@ -2596,7 +2597,7 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len) !in_range(mem_from, lock_to, mem_to)) continue; - print_freed_lock_bug(curr, mem_from, mem_to); + print_freed_lock_bug(curr, mem_from, mem_to, hlock); break; } local_irq_restore(flags); -- cgit v1.2.3 From d6d897cec29252b8d0785198cfa6ca16d30c739d Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 10 Jul 2006 04:44:04 -0700 Subject: [PATCH] lockdep: core, reduce per-lock class-cache size lockdep_map is embedded into every lock, which blows up data structure sizes all around the kernel. Reduce the class-cache to be for the default class only - that is used in 99.9% of the cases and even if we dont have a class cached, the lookup in the class-hash is lockless. This change reduces the per-lock dep_map overhead by 56 bytes on 64-bit platforms and by 28 bytes on 32-bit platforms. Signed-off-by: Ingo Molnar Cc: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/lockdep.c | 87 +++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 54 insertions(+), 33 deletions(-) (limited to 'kernel/lockdep.c') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index c1f34addd00..9bad1788451 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -1104,7 +1104,7 @@ extern void __error_too_big_MAX_LOCKDEP_SUBCLASSES(void); * itself, so actual lookup of the hash should be once per lock object. */ static inline struct lock_class * -register_lock_class(struct lockdep_map *lock, unsigned int subclass) +look_up_lock_class(struct lockdep_map *lock, unsigned int subclass) { struct lockdep_subclass_key *key; struct list_head *hash_head; @@ -1148,7 +1148,26 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass) */ list_for_each_entry(class, hash_head, hash_entry) if (class->key == key) - goto out_set; + return class; + + return NULL; +} + +/* + * Register a lock's class in the hash-table, if the class is not present + * yet. Otherwise we look it up. We cache the result in the lock object + * itself, so actual lookup of the hash should be once per lock object. + */ +static inline struct lock_class * +register_lock_class(struct lockdep_map *lock, unsigned int subclass) +{ + struct lockdep_subclass_key *key; + struct list_head *hash_head; + struct lock_class *class; + + class = look_up_lock_class(lock, subclass); + if (likely(class)) + return class; /* * Debug-check: all keys must be persistent! @@ -1163,6 +1182,9 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass) return NULL; } + key = lock->key->subkeys + subclass; + hash_head = classhashentry(key); + __raw_spin_lock(&hash_lock); /* * We have to do the hash-walk again, to avoid races @@ -1209,8 +1231,8 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass) out_unlock_set: __raw_spin_unlock(&hash_lock); -out_set: - lock->class[subclass] = class; + if (!subclass) + lock->class_cache = class; DEBUG_LOCKS_WARN_ON(class->subclass != subclass); @@ -1914,7 +1936,7 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name, } lock->name = name; lock->key = key; - memset(lock->class, 0, sizeof(lock->class[0])*MAX_LOCKDEP_SUBCLASSES); + lock->class_cache = NULL; } EXPORT_SYMBOL_GPL(lockdep_init_map); @@ -1928,8 +1950,8 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, unsigned long ip) { struct task_struct *curr = current; + struct lock_class *class = NULL; struct held_lock *hlock; - struct lock_class *class; unsigned int depth, id; int chain_head = 0; u64 chain_key; @@ -1947,8 +1969,11 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, return 0; } - class = lock->class[subclass]; - /* not cached yet? */ + if (!subclass) + class = lock->class_cache; + /* + * Not cached yet or subclass? + */ if (unlikely(!class)) { class = register_lock_class(lock, subclass); if (!class) @@ -2449,48 +2474,44 @@ void lockdep_free_key_range(void *start, unsigned long size) void lockdep_reset_lock(struct lockdep_map *lock) { - struct lock_class *class, *next, *entry; + struct lock_class *class, *next; struct list_head *head; unsigned long flags; int i, j; raw_local_irq_save(flags); - __raw_spin_lock(&hash_lock); /* - * Remove all classes this lock has: + * Remove all classes this lock might have: + */ + for (j = 0; j < MAX_LOCKDEP_SUBCLASSES; j++) { + /* + * If the class exists we look it up and zap it: + */ + class = look_up_lock_class(lock, j); + if (class) + zap_class(class); + } + /* + * Debug check: in the end all mapped classes should + * be gone. */ + __raw_spin_lock(&hash_lock); for (i = 0; i < CLASSHASH_SIZE; i++) { head = classhash_table + i; if (list_empty(head)) continue; list_for_each_entry_safe(class, next, head, hash_entry) { - for (j = 0; j < MAX_LOCKDEP_SUBCLASSES; j++) { - entry = lock->class[j]; - if (class == entry) { - zap_class(class); - lock->class[j] = NULL; - break; - } + if (unlikely(class == lock->class_cache)) { + __raw_spin_unlock(&hash_lock); + DEBUG_LOCKS_WARN_ON(1); + goto out_restore; } } } - - /* - * Debug check: in the end all mapped classes should - * be gone. - */ - for (j = 0; j < MAX_LOCKDEP_SUBCLASSES; j++) { - entry = lock->class[j]; - if (!entry) - continue; - __raw_spin_unlock(&hash_lock); - DEBUG_LOCKS_WARN_ON(1); - raw_local_irq_restore(flags); - return; - } - __raw_spin_unlock(&hash_lock); + +out_restore: raw_local_irq_restore(flags); } -- cgit v1.2.3