Messages in this thread Patch in this message | | | Date | Tue, 16 Jul 2002 19:22:13 -0700 | From | Jesse Barnes <> | Subject | Re: spinlock assertion macros |
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On Fri, Jul 12, 2002 at 07:42:09PM +0200, Daniel Phillips wrote: > So far, only the MUST_HOLD style of executable locking documentation has > really survived scrutiny. It needs some variants: MUST_HOLD_READ, > MUST_HOLD_WRITE, MUST_HOLD_SEM, MUST_HOLD_READ_SEM and MUST_HOLD_WRITE_SEM, > or names to that effect.
I'm not quite sure where to put the semaphore versions of the MUST_* macros, I guess they'd have to go in each of the arch-specific header files? Anyway, I've got spinlock and rwlock versions of them below, maybe they're useful enough to go in as a start? I only coded the ia64 version of rwlock_is_*_locked since it was easy--the i386 versions were a little intimidating...
I thought Oliver's suggestion for tracking the order of spinlock acquisition was good, hopefully someone will take a stab at it along with Dave's FUNCTION_SLEEPS() implementation.
Jesse
diff -Naur -X /home/jbarnes/dontdiff linux-2.5.25/fs/inode.c linux-2.5.25-spinassert/fs/inode.c --- linux-2.5.25/fs/inode.c Fri Jul 5 16:42:38 2002 +++ linux-2.5.25-spinassert/fs/inode.c Tue Jul 16 19:04:01 2002 @@ -183,6 +183,8 @@ */ void __iget(struct inode * inode) { + MUST_HOLD_SPIN(&inode_lock); + if (atomic_read(&inode->i_count)) { atomic_inc(&inode->i_count); return; diff -Naur -X /home/jbarnes/dontdiff linux-2.5.25/include/asm-ia64/spinlock.h linux-2.5.25-spinassert/include/asm-ia64/spinlock.h --- linux-2.5.25/include/asm-ia64/spinlock.h Fri Jul 5 16:42:03 2002 +++ linux-2.5.25-spinassert/include/asm-ia64/spinlock.h Tue Jul 16 18:31:53 2002 @@ -109,6 +109,8 @@ #define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 } #define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0) +#define rwlock_is_read_locked(x) ((x)->read_counter != 0 || (x)->write_lock != 0) +#define rwlock_is_write_locked(x) ((x)->write_lock != 0) #define _raw_read_lock(rw) \ do { \ diff -Naur -X /home/jbarnes/dontdiff linux-2.5.25/include/linux/spinlock.h linux-2.5.25-spinassert/include/linux/spinlock.h --- linux-2.5.25/include/linux/spinlock.h Fri Jul 5 16:42:24 2002 +++ linux-2.5.25-spinassert/include/linux/spinlock.h Tue Jul 16 18:58:40 2002 @@ -116,7 +116,21 @@ #define _raw_write_lock(lock) (void)(lock) /* Not "unused variable". */ #define _raw_write_unlock(lock) do { } while(0) -#endif /* !SMP */ +#endif /* !CONFIG_SMP */ + +/* + * Simple lock assertions for debugging and documenting where locks need + * to be locked/unlocked. + */ +#if defined(CONFIG_DEBUG_SPINLOCK) && defined(CONFIG_SMP) +#define MUST_HOLD_SPIN(lock) BUG_ON(!spin_is_locked(lock)) +#define MUST_HOLD_READ(lock) BUG_ON(!rwlock_is_read_locked(lock)) +#define MUST_HOLD_WRITE(lock) BUG_ON(!rwlock_is_write_locked(lock)) +#else +#define MUST_HOLD_SPIN(lock) do { } while(0) +#define MUST_HOLD_READ(lock) do { } while(0) +#define MUST_HOLD_WRITE(lock) do { } while(0) +#endif /* CONFIG_DEBUG_SPINLOCK && CONFIG_SMP */ #ifdef CONFIG_PREEMPT - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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