android_kernel_motorola_sm6225/fs/xfs/xfs_mru_cache.h
David Chinner 65de556756 [XFS] On-demand reaping of the MRU cache
Instead of running the mru cache reaper all the time based on a timeout,
we should only run it when the cache has active objects. This allows CPUs
to sleep when there is no activity rather than be woken repeatedly just to
check if there is anything to do.

SGI-PV: 968554
SGI-Modid: xfs-linux-melb:xfs-kern:29305a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-09-17 16:42:02 +10:00

55 lines
2.4 KiB
C

/*
* Copyright (c) 2006-2007 Silicon Graphics, Inc.
* 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 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would 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 the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __XFS_MRU_CACHE_H__
#define __XFS_MRU_CACHE_H__
/* Function pointer type for callback to free a client's data pointer. */
typedef void (*xfs_mru_cache_free_func_t)(unsigned long, void*);
typedef struct xfs_mru_cache
{
struct radix_tree_root store; /* Core storage data structure. */
struct list_head *lists; /* Array of lists, one per grp. */
struct list_head reap_list; /* Elements overdue for reaping. */
spinlock_t lock; /* Lock to protect this struct. */
unsigned int grp_count; /* Number of discrete groups. */
unsigned int grp_time; /* Time period spanned by grps. */
unsigned int lru_grp; /* Group containing time zero. */
unsigned long time_zero; /* Time first element was added. */
xfs_mru_cache_free_func_t free_func; /* Function pointer for freeing. */
struct delayed_work work; /* Workqueue data for reaping. */
unsigned int queued; /* work has been queued */
} xfs_mru_cache_t;
int xfs_mru_cache_init(void);
void xfs_mru_cache_uninit(void);
int xfs_mru_cache_create(struct xfs_mru_cache **mrup, unsigned int lifetime_ms,
unsigned int grp_count,
xfs_mru_cache_free_func_t free_func);
void xfs_mru_cache_flush(xfs_mru_cache_t *mru);
void xfs_mru_cache_destroy(struct xfs_mru_cache *mru);
int xfs_mru_cache_insert(struct xfs_mru_cache *mru, unsigned long key,
void *value);
void * xfs_mru_cache_remove(struct xfs_mru_cache *mru, unsigned long key);
void xfs_mru_cache_delete(struct xfs_mru_cache *mru, unsigned long key);
void *xfs_mru_cache_lookup(struct xfs_mru_cache *mru, unsigned long key);
void *xfs_mru_cache_peek(struct xfs_mru_cache *mru, unsigned long key);
void xfs_mru_cache_done(struct xfs_mru_cache *mru);
#endif /* __XFS_MRU_CACHE_H__ */