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13 June 2022, 11:31:42 UTC
Revision 59c84ed0ddc11f1823b4a33ace4fbcc948261bb2 authored by Jan Kara on 05 June 2012, 22:32:26 UTC, committed by Ben Myers on 21 June 2012, 19:20:36 UTC 
xfs: Fix overallocation in xfs_buf_allocate_memory()
 
Commit de1cbee which removed b_file_offset in favor of b_bn introduced a bug
causing xfs_buf_allocate_memory() to overestimate the number of necessary
pages. The problem is that xfs_buf_alloc() sets b_bn to -1 and thus effectively
every buffer is straddling a page boundary which causes
xfs_buf_allocate_memory() to allocate two pages and use vmalloc() for access
which is unnecessary.

Dave says xfs_buf_alloc() doesn't need to set b_bn to -1 anymore since the
buffer is inserted into the cache only after being fully initialized now.
So just make xfs_buf_alloc() fill in proper block number from the beginning.

CC: David Chinner <dchinner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
1 parent 76d0953
Raw File
Tip revision: 59c84ed0ddc11f1823b4a33ace4fbcc948261bb2 authored by Jan Kara on 05 June 2012, 22:32:26 UTC
xfs: Fix overallocation in xfs_buf_allocate_memory()
Tip revision: 59c84ed
mutex-debug.h 
/*
 * Mutexes: blocking mutual exclusion locks
 *
 * started by Ingo Molnar:
 *
 *  Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 *
 * This file contains mutex debugging related internal declarations,
 * prototypes and inline functions, for the CONFIG_DEBUG_MUTEXES case.
 * More details are in kernel/mutex-debug.c.
 */

/*
 * This must be called with lock->wait_lock held.
 */
extern void debug_mutex_lock_common(struct mutex *lock,
				    struct mutex_waiter *waiter);
extern void debug_mutex_wake_waiter(struct mutex *lock,
				    struct mutex_waiter *waiter);
extern void debug_mutex_free_waiter(struct mutex_waiter *waiter);
extern void debug_mutex_add_waiter(struct mutex *lock,
				   struct mutex_waiter *waiter,
				   struct thread_info *ti);
extern void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
				struct thread_info *ti);
extern void debug_mutex_unlock(struct mutex *lock);
extern void debug_mutex_init(struct mutex *lock, const char *name,
			     struct lock_class_key *key);

static inline void mutex_set_owner(struct mutex *lock)
{
	lock->owner = current;
}

static inline void mutex_clear_owner(struct mutex *lock)
{
	lock->owner = NULL;
}

#define spin_lock_mutex(lock, flags)			\
	do {						\
		struct mutex *l = container_of(lock, struct mutex, wait_lock); \
							\
		DEBUG_LOCKS_WARN_ON(in_interrupt());	\
		local_irq_save(flags);			\
		arch_spin_lock(&(lock)->rlock.raw_lock);\
		DEBUG_LOCKS_WARN_ON(l->magic != l);	\
	} while (0)

#define spin_unlock_mutex(lock, flags)				\
	do {							\
		arch_spin_unlock(&(lock)->rlock.raw_lock);	\
		local_irq_restore(flags);			\
		preempt_check_resched();			\
	} while (0)
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