alistair23-linux/fs/btrfs/locking.h
Chris Mason 284b066af4 Btrfs: don't use spin_is_contended
Btrfs was using spin_is_contended to see if it should drop locks before
doing extent allocations during btrfs_search_slot.  The idea was to avoid
expensive searches in the tree unless the lock was actually contended.

But, spin_is_contended is specific to the ticket spinlocks on x86, so this
is causing compile errors everywhere else.

In practice, the contention could easily appear some time after we started
doing the extent allocation, and it makes more sense to always drop the lock
instead.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-09 16:22:03 -05:00

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C

/*
* Copyright (C) 2008 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#ifndef __BTRFS_LOCKING_
#define __BTRFS_LOCKING_
int btrfs_tree_lock(struct extent_buffer *eb);
int btrfs_tree_unlock(struct extent_buffer *eb);
int btrfs_tree_locked(struct extent_buffer *eb);
int btrfs_try_tree_lock(struct extent_buffer *eb);
int btrfs_try_spin_lock(struct extent_buffer *eb);
void btrfs_set_lock_blocking(struct extent_buffer *eb);
void btrfs_clear_lock_blocking(struct extent_buffer *eb);
#endif