diff options
| -rw-r--r-- | include/linux/hardirq.h | 9 | ||||
| -rw-r--r-- | include/linux/smp_lock.h | 65 | ||||
| -rw-r--r-- | init/Kconfig | 5 | ||||
| -rw-r--r-- | kernel/sched.c | 9 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 9 | ||||
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/kernel_lock.c | 136 |
7 files changed, 2 insertions, 232 deletions
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 32f9fd6..ba36217 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -93,13 +93,6 @@ */ #define in_nmi() (preempt_count() & NMI_MASK) -#if defined(CONFIG_PREEMPT) && defined(CONFIG_BKL) -# include <linux/sched.h> -# define PREEMPT_INATOMIC_BASE (current->lock_depth >= 0) -#else -# define PREEMPT_INATOMIC_BASE 0 -#endif - #if defined(CONFIG_PREEMPT) # define PREEMPT_CHECK_OFFSET 1 #else @@ -113,7 +106,7 @@ * used in the general case to determine whether sleeping is possible. * Do not use in_atomic() in driver code. */ -#define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_INATOMIC_BASE) +#define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != 0) /* * Check whether we were atomic before we did preempt_disable(): diff --git a/include/linux/smp_lock.h b/include/linux/smp_lock.h deleted file mode 100644 index 3a19882..0000000 --- a/include/linux/smp_lock.h +++ /dev/null @@ -1,65 +0,0 @@ -#ifndef __LINUX_SMPLOCK_H -#define __LINUX_SMPLOCK_H - -#ifdef CONFIG_LOCK_KERNEL -#include <linux/sched.h> - -extern int __lockfunc __reacquire_kernel_lock(void); -extern void __lockfunc __release_kernel_lock(void); - -/* - * Release/re-acquire global kernel lock for the scheduler - */ -#define release_kernel_lock(tsk) do { \ - if (unlikely((tsk)->lock_depth >= 0)) \ - __release_kernel_lock(); \ -} while (0) - -static inline int reacquire_kernel_lock(struct task_struct *task) -{ - if (unlikely(task->lock_depth >= 0)) - return __reacquire_kernel_lock(); - return 0; -} - -extern void __lockfunc -_lock_kernel(const char *func, const char *file, int line) -__acquires(kernel_lock); - -extern void __lockfunc -_unlock_kernel(const char *func, const char *file, int line) -__releases(kernel_lock); - -#define lock_kernel() do { \ - _lock_kernel(__func__, __FILE__, __LINE__); \ -} while (0) - -#define unlock_kernel() do { \ - _unlock_kernel(__func__, __FILE__, __LINE__); \ -} while (0) - -/* - * Various legacy drivers don't really need the BKL in a specific - * function, but they *do* need to know that the BKL became available. - * This function just avoids wrapping a bunch of lock/unlock pairs - * around code which doesn't really need it. - */ -static inline void cycle_kernel_lock(void) -{ - lock_kernel(); - unlock_kernel(); -} - -#else - -#ifdef CONFIG_BKL /* provoke build bug if not set */ -#define lock_kernel() -#define unlock_kernel() -#define cycle_kernel_lock() do { } while(0) -#endif /* CONFIG_BKL */ - -#define release_kernel_lock(task) do { } while(0) -#define reacquire_kernel_lock(task) 0 - -#endif /* CONFIG_LOCK_KERNEL */ -#endif /* __LINUX_SMPLOCK_H */ diff --git a/init/Kconfig b/init/Kconfig index be788c0..a88d1c9 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -69,11 +69,6 @@ config BROKEN_ON_SMP depends on BROKEN || !SMP default y -config LOCK_KERNEL - bool - depends on (SMP || PREEMPT) && BKL - default y - config INIT_ENV_ARG_LIMIT int default 32 if !UML diff --git a/kernel/sched.c b/kernel/sched.c index 18d38e4..827c170 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -32,7 +32,6 @@ #include <linux/init.h> #include <linux/uaccess.h> #include <linux/highmem.h> -#include <linux/smp_lock.h> #include <asm/mmu_context.h> #include <linux/interrupt.h> #include <linux/capability.h> @@ -3945,9 +3944,6 @@ need_resched: rcu_note_context_switch(cpu); prev = rq->curr; - release_kernel_lock(prev); -need_resched_nonpreemptible: - schedule_debug(prev); if (sched_feat(HRTICK)) @@ -4010,9 +4006,6 @@ need_resched_nonpreemptible: post_schedule(rq); - if (unlikely(reacquire_kernel_lock(prev))) - goto need_resched_nonpreemptible; - preempt_enable_no_resched(); if (need_resched()) goto need_resched; @@ -8074,7 +8067,7 @@ static inline int preempt_count_equals(int preempt_offset) { int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); - return (nested == PREEMPT_INATOMIC_BASE + preempt_offset); + return (nested == preempt_offset); } void __might_sleep(const char *file, int line, int preempt_offset) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 2b97418..6f440d8 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -470,15 +470,6 @@ config DEBUG_MUTEXES This feature allows mutex semantics violations to be detected and reported. -config BKL - bool "Big Kernel Lock" if (SMP || PREEMPT) - default y - help - This is the traditional lock that is used in old code instead - of proper locking. All drivers that use the BKL should depend - on this symbol. - Say Y here unless you are working on removing the BKL. - config DEBUG_LOCK_ALLOC bool "Lock debugging: detect incorrect freeing of live locks" depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT diff --git a/lib/Makefile b/lib/Makefile index cbb774f..de6c609 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -43,7 +43,6 @@ obj-$(CONFIG_GENERIC_FIND_LAST_BIT) += find_last_bit.o CFLAGS_hweight.o = $(subst $(quote),,$(CONFIG_ARCH_HWEIGHT_CFLAGS)) obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o -obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o obj-$(CONFIG_BTREE) += btree.o obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o obj-$(CONFIG_DEBUG_LIST) += list_debug.o diff --git a/lib/kernel_lock.c b/lib/kernel_lock.c deleted file mode 100644 index d80e122..0000000 --- a/lib/kernel_lock.c +++ /dev/null @@ -1,136 +0,0 @@ -/* - * lib/kernel_lock.c - * - * This is the traditional BKL - big kernel lock. Largely - * relegated to obsolescence, but used by various less - * important (or lazy) subsystems. - */ -#include <linux/module.h> -#include <linux/kallsyms.h> -#include <linux/semaphore.h> -#include <linux/smp_lock.h> - -/* - * The 'big kernel lock' - * - * This spinlock is taken and released recursively by lock_kernel() - * and unlock_kernel(). It is transparently dropped and reacquired - * over schedule(). It is used to protect legacy code that hasn't - * been migrated to a proper locking design yet. - * - * Don't use in new code. - */ -static __cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(kernel_flag); - - -/* - * Acquire/release the underlying lock from the scheduler. - * - * This is called with preemption disabled, and should - * return an error value if it cannot get the lock and - * TIF_NEED_RESCHED gets set. - * - * If it successfully gets the lock, it should increment - * the preemption count like any spinlock does. - * - * (This works on UP too - do_raw_spin_trylock will never - * return false in that case) - */ -int __lockfunc __reacquire_kernel_lock(void) -{ - while (!do_raw_spin_trylock(&kernel_flag)) { - if (need_resched()) - return -EAGAIN; - cpu_relax(); - } - preempt_disable(); - return 0; -} - -void __lockfunc __release_kernel_lock(void) -{ - do_raw_spin_unlock(&kernel_flag); - preempt_enable_no_resched(); -} - -/* - * These are the BKL spinlocks - we try to be polite about preemption. - * If SMP is not on (ie UP preemption), this all goes away because the - * do_raw_spin_trylock() will always succeed. - */ -#ifdef CONFIG_PREEMPT -static inline void __lock_kernel(void) -{ - preempt_disable(); - if (unlikely(!do_raw_spin_trylock(&kernel_flag))) { - /* - * If preemption was disabled even before this - * was called, there's nothing we can be polite - * about - just spin. - */ - if (preempt_count() > 1) { - do_raw_spin_lock(&kernel_flag); - return; - } - - /* - * Otherwise, let's wait for the kernel lock - * with preemption enabled.. - */ - do { - preempt_enable(); - while (raw_spin_is_locked(&kernel_flag)) - cpu_relax(); - preempt_disable(); - } while (!do_raw_spin_trylock(&kernel_flag)); - } -} - -#else - -/* - * Non-preemption case - just get the spinlock - */ -static inline void __lock_kernel(void) -{ - do_raw_spin_lock(&kernel_flag); -} -#endif - -static inline void __unlock_kernel(void) -{ - /* - * the BKL is not covered by lockdep, so we open-code the - * unlocking sequence (and thus avoid the dep-chain ops): - */ - do_raw_spin_unlock(&kernel_flag); - preempt_enable(); -} - -/* - * Getting the big kernel lock. - * - * This cannot happen asynchronously, so we only need to - * worry about other CPU's. - */ -void __lockfunc _lock_kernel(const char *func, const char *file, int line) -{ - int depth = current->lock_depth + 1; - - if (likely(!depth)) { - might_sleep(); - __lock_kernel(); - } - current->lock_depth = depth; -} - -void __lockfunc _unlock_kernel(const char *func, const char *file, int line) -{ - BUG_ON(current->lock_depth < 0); - if (likely(--current->lock_depth < 0)) - __unlock_kernel(); -} - -EXPORT_SYMBOL(_lock_kernel); -EXPORT_SYMBOL(_unlock_kernel); - |