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Kernel v2.6.25-rc7 /lib/kernel_lock.c

Filename:/lib/kernel_lock.c
Lines Added:0
Lines Deleted:123
Also changed in: (Previous) 2.6.25-rc6  2.6.25-rc5  2.6.25-rc4  2.6.25-rc3  2.6.25-rc2  2.6.25-rc1 
(Following) 2.6.25-rc8  2.6.25-rc9  2.6.25  2.6.25-git1  2.6.25-git2  2.6.25-git3 

Location
[  2.6.25-rc7
  [  lib
     o  kernel_lock.c

Patch

diff --git a/lib/kernel_lock.c b/lib/kernel_lock.c
index f73e2f8..812dbf0 100644
--- a/lib/kernel_lock.c
+++ b/lib/kernel_lock.c
@@ -9,7 +9,6 @@
 #include <linux/module.h>
 #include <linux/kallsyms.h>
 
-#ifdef CONFIG_PREEMPT_BKL
 /*
  * The 'big kernel semaphore'
  *
@@ -86,128 +85,6 @@ void __lockfunc unlock_kernel(void)
       up(&kernel_sem);
 }
 
-#else
-
-/*
- * 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_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 - _raw_spin_trylock will never
- * return false in that case)
- */
-int __lockfunc __reacquire_kernel_lock(void)
-{
-   while (!_raw_spin_trylock(&kernel_flag)) {
-      if (test_thread_flag(TIF_NEED_RESCHED))
-         return -EAGAIN;
-      cpu_relax();
-   }
-   preempt_disable();
-   return 0;
-}
-
-void __lockfunc __release_kernel_lock(void)
-{
-   _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
- * _raw_spin_trylock() will always succeed.
- */
-#ifdef CONFIG_PREEMPT
-static inline void __lock_kernel(void)
-{
-   preempt_disable();
-   if (unlikely(!_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) {
-         _raw_spin_lock(&kernel_flag);
-         return;
-      }
-
-      /*
-       * Otherwise, let's wait for the kernel lock
-       * with preemption enabled..
-       */
-      do {
-         preempt_enable();
-         while (spin_is_locked(&kernel_flag))
-            cpu_relax();
-         preempt_disable();
-      } while (!_raw_spin_trylock(&kernel_flag));
-   }
-}
-
-#else
-
-/*
- * Non-preemption case - just get the spinlock
- */
-static inline void __lock_kernel(void)
-{
-   _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):
-    */
-   _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(void)
-{
-   int depth = current->lock_depth+1;
-   if (likely(!depth))
-      __lock_kernel();
-   current->lock_depth = depth;
-}
-
-void __lockfunc unlock_kernel(void)
-{
-   BUG_ON(current->lock_depth < 0);
-   if (likely(--current->lock_depth < 0))
-      __unlock_kernel();
-}
-
-#endif
-
 EXPORT_SYMBOL(lock_kernel);
 EXPORT_SYMBOL(unlock_kernel);
 


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