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author | Peter Zijlstra <peterz@infradead.org> | 2013-10-31 18:15:36 +0100 |
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committer | Ingo Molnar <mingo@kernel.org> | 2013-11-06 07:55:21 +0100 |
commit | 60fc28746a7b61775ae28950ddf7a4ac15955639 (patch) | |
tree | 427ff89f3beaeca421ca25bbfd7c882c0b0c736b /lib/spinlock_debug.c | |
parent | 8eddac3f103736163f49255bcb109edadea167f6 (diff) | |
download | lwn-60fc28746a7b61775ae28950ddf7a4ac15955639.tar.gz lwn-60fc28746a7b61775ae28950ddf7a4ac15955639.zip |
locking: Move the spinlock code to kernel/locking/
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-b81ol0z3mon45m51o131yc9j@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'lib/spinlock_debug.c')
-rw-r--r-- | lib/spinlock_debug.c | 302 |
1 files changed, 0 insertions, 302 deletions
diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c deleted file mode 100644 index 0374a596cffa..000000000000 --- a/lib/spinlock_debug.c +++ /dev/null @@ -1,302 +0,0 @@ -/* - * Copyright 2005, Red Hat, Inc., Ingo Molnar - * Released under the General Public License (GPL). - * - * This file contains the spinlock/rwlock implementations for - * DEBUG_SPINLOCK. - */ - -#include <linux/spinlock.h> -#include <linux/nmi.h> -#include <linux/interrupt.h> -#include <linux/debug_locks.h> -#include <linux/delay.h> -#include <linux/export.h> - -void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name, - struct lock_class_key *key) -{ -#ifdef CONFIG_DEBUG_LOCK_ALLOC - /* - * Make sure we are not reinitializing a held lock: - */ - debug_check_no_locks_freed((void *)lock, sizeof(*lock)); - lockdep_init_map(&lock->dep_map, name, key, 0); -#endif - lock->raw_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; - lock->magic = SPINLOCK_MAGIC; - lock->owner = SPINLOCK_OWNER_INIT; - lock->owner_cpu = -1; -} - -EXPORT_SYMBOL(__raw_spin_lock_init); - -void __rwlock_init(rwlock_t *lock, const char *name, - struct lock_class_key *key) -{ -#ifdef CONFIG_DEBUG_LOCK_ALLOC - /* - * Make sure we are not reinitializing a held lock: - */ - debug_check_no_locks_freed((void *)lock, sizeof(*lock)); - lockdep_init_map(&lock->dep_map, name, key, 0); -#endif - lock->raw_lock = (arch_rwlock_t) __ARCH_RW_LOCK_UNLOCKED; - lock->magic = RWLOCK_MAGIC; - lock->owner = SPINLOCK_OWNER_INIT; - lock->owner_cpu = -1; -} - -EXPORT_SYMBOL(__rwlock_init); - -static void spin_dump(raw_spinlock_t *lock, const char *msg) -{ - struct task_struct *owner = NULL; - - if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT) - owner = lock->owner; - printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n", - msg, raw_smp_processor_id(), - current->comm, task_pid_nr(current)); - printk(KERN_EMERG " lock: %pS, .magic: %08x, .owner: %s/%d, " - ".owner_cpu: %d\n", - lock, lock->magic, - owner ? owner->comm : "<none>", - owner ? task_pid_nr(owner) : -1, - lock->owner_cpu); - dump_stack(); -} - -static void spin_bug(raw_spinlock_t *lock, const char *msg) -{ - if (!debug_locks_off()) - return; - - spin_dump(lock, msg); -} - -#define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg) - -static inline void -debug_spin_lock_before(raw_spinlock_t *lock) -{ - SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); - SPIN_BUG_ON(lock->owner == current, lock, "recursion"); - SPIN_BUG_ON(lock->owner_cpu == raw_smp_processor_id(), - lock, "cpu recursion"); -} - -static inline void debug_spin_lock_after(raw_spinlock_t *lock) -{ - lock->owner_cpu = raw_smp_processor_id(); - lock->owner = current; -} - -static inline void debug_spin_unlock(raw_spinlock_t *lock) -{ - SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); - SPIN_BUG_ON(!raw_spin_is_locked(lock), lock, "already unlocked"); - SPIN_BUG_ON(lock->owner != current, lock, "wrong owner"); - SPIN_BUG_ON(lock->owner_cpu != raw_smp_processor_id(), - lock, "wrong CPU"); - lock->owner = SPINLOCK_OWNER_INIT; - lock->owner_cpu = -1; -} - -static void __spin_lock_debug(raw_spinlock_t *lock) -{ - u64 i; - u64 loops = loops_per_jiffy * HZ; - - for (i = 0; i < loops; i++) { - if (arch_spin_trylock(&lock->raw_lock)) - return; - __delay(1); - } - /* lockup suspected: */ - spin_dump(lock, "lockup suspected"); -#ifdef CONFIG_SMP - trigger_all_cpu_backtrace(); -#endif - - /* - * The trylock above was causing a livelock. Give the lower level arch - * specific lock code a chance to acquire the lock. We have already - * printed a warning/backtrace at this point. The non-debug arch - * specific code might actually succeed in acquiring the lock. If it is - * not successful, the end-result is the same - there is no forward - * progress. - */ - arch_spin_lock(&lock->raw_lock); -} - -void do_raw_spin_lock(raw_spinlock_t *lock) -{ - debug_spin_lock_before(lock); - if (unlikely(!arch_spin_trylock(&lock->raw_lock))) - __spin_lock_debug(lock); - debug_spin_lock_after(lock); -} - -int do_raw_spin_trylock(raw_spinlock_t *lock) -{ - int ret = arch_spin_trylock(&lock->raw_lock); - - if (ret) - debug_spin_lock_after(lock); -#ifndef CONFIG_SMP - /* - * Must not happen on UP: - */ - SPIN_BUG_ON(!ret, lock, "trylock failure on UP"); -#endif - return ret; -} - -void do_raw_spin_unlock(raw_spinlock_t *lock) -{ - debug_spin_unlock(lock); - arch_spin_unlock(&lock->raw_lock); -} - -static void rwlock_bug(rwlock_t *lock, const char *msg) -{ - if (!debug_locks_off()) - return; - - printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p\n", - msg, raw_smp_processor_id(), current->comm, - task_pid_nr(current), lock); - dump_stack(); -} - -#define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg) - -#if 0 /* __write_lock_debug() can lock up - maybe this can too? */ -static void __read_lock_debug(rwlock_t *lock) -{ - u64 i; - u64 loops = loops_per_jiffy * HZ; - int print_once = 1; - - for (;;) { - for (i = 0; i < loops; i++) { - if (arch_read_trylock(&lock->raw_lock)) - return; - __delay(1); - } - /* lockup suspected: */ - if (print_once) { - print_once = 0; - printk(KERN_EMERG "BUG: read-lock lockup on CPU#%d, " - "%s/%d, %p\n", - raw_smp_processor_id(), current->comm, - current->pid, lock); - dump_stack(); - } - } -} -#endif - -void do_raw_read_lock(rwlock_t *lock) -{ - RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); - arch_read_lock(&lock->raw_lock); -} - -int do_raw_read_trylock(rwlock_t *lock) -{ - int ret = arch_read_trylock(&lock->raw_lock); - -#ifndef CONFIG_SMP - /* - * Must not happen on UP: - */ - RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP"); -#endif - return ret; -} - -void do_raw_read_unlock(rwlock_t *lock) -{ - RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); - arch_read_unlock(&lock->raw_lock); -} - -static inline void debug_write_lock_before(rwlock_t *lock) -{ - RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); - RWLOCK_BUG_ON(lock->owner == current, lock, "recursion"); - RWLOCK_BUG_ON(lock->owner_cpu == raw_smp_processor_id(), - lock, "cpu recursion"); -} - -static inline void debug_write_lock_after(rwlock_t *lock) -{ - lock->owner_cpu = raw_smp_processor_id(); - lock->owner = current; -} - -static inline void debug_write_unlock(rwlock_t *lock) -{ - RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic"); - RWLOCK_BUG_ON(lock->owner != current, lock, "wrong owner"); - RWLOCK_BUG_ON(lock->owner_cpu != raw_smp_processor_id(), - lock, "wrong CPU"); - lock->owner = SPINLOCK_OWNER_INIT; - lock->owner_cpu = -1; -} - -#if 0 /* This can cause lockups */ -static void __write_lock_debug(rwlock_t *lock) -{ - u64 i; - u64 loops = loops_per_jiffy * HZ; - int print_once = 1; - - for (;;) { - for (i = 0; i < loops; i++) { - if (arch_write_trylock(&lock->raw_lock)) - return; - __delay(1); - } - /* lockup suspected: */ - if (print_once) { - print_once = 0; - printk(KERN_EMERG "BUG: write-lock lockup on CPU#%d, " - "%s/%d, %p\n", - raw_smp_processor_id(), current->comm, - current->pid, lock); - dump_stack(); - } - } -} -#endif - -void do_raw_write_lock(rwlock_t *lock) -{ - debug_write_lock_before(lock); - arch_write_lock(&lock->raw_lock); - debug_write_lock_after(lock); -} - -int do_raw_write_trylock(rwlock_t *lock) -{ - int ret = arch_write_trylock(&lock->raw_lock); - - if (ret) - debug_write_lock_after(lock); -#ifndef CONFIG_SMP - /* - * Must not happen on UP: - */ - RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP"); -#endif - return ret; -} - -void do_raw_write_unlock(rwlock_t *lock) -{ - debug_write_unlock(lock); - arch_write_unlock(&lock->raw_lock); -} |