mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 13:43:55 +08:00
612d6c19db
The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
78 lines
2.5 KiB
C
78 lines
2.5 KiB
C
/*
|
|
* Copyright (C) 2001 Momchil Velikov
|
|
* Portions Copyright (C) 2001 Christoph Hellwig
|
|
*
|
|
* 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; either version 2, or (at
|
|
* your option) any later version.
|
|
*
|
|
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
*/
|
|
#ifndef _LINUX_RADIX_TREE_H
|
|
#define _LINUX_RADIX_TREE_H
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/preempt.h>
|
|
#include <linux/types.h>
|
|
|
|
#define RADIX_TREE_MAX_TAGS 2
|
|
|
|
/* root tags are stored in gfp_mask, shifted by __GFP_BITS_SHIFT */
|
|
struct radix_tree_root {
|
|
unsigned int height;
|
|
gfp_t gfp_mask;
|
|
struct radix_tree_node *rnode;
|
|
};
|
|
|
|
#define RADIX_TREE_INIT(mask) { \
|
|
.height = 0, \
|
|
.gfp_mask = (mask), \
|
|
.rnode = NULL, \
|
|
}
|
|
|
|
#define RADIX_TREE(name, mask) \
|
|
struct radix_tree_root name = RADIX_TREE_INIT(mask)
|
|
|
|
#define INIT_RADIX_TREE(root, mask) \
|
|
do { \
|
|
(root)->height = 0; \
|
|
(root)->gfp_mask = (mask); \
|
|
(root)->rnode = NULL; \
|
|
} while (0)
|
|
|
|
int radix_tree_insert(struct radix_tree_root *, unsigned long, void *);
|
|
void *radix_tree_lookup(struct radix_tree_root *, unsigned long);
|
|
void **radix_tree_lookup_slot(struct radix_tree_root *, unsigned long);
|
|
void *radix_tree_delete(struct radix_tree_root *, unsigned long);
|
|
unsigned int
|
|
radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
|
|
unsigned long first_index, unsigned int max_items);
|
|
int radix_tree_preload(gfp_t gfp_mask);
|
|
void radix_tree_init(void);
|
|
void *radix_tree_tag_set(struct radix_tree_root *root,
|
|
unsigned long index, unsigned int tag);
|
|
void *radix_tree_tag_clear(struct radix_tree_root *root,
|
|
unsigned long index, unsigned int tag);
|
|
int radix_tree_tag_get(struct radix_tree_root *root,
|
|
unsigned long index, unsigned int tag);
|
|
unsigned int
|
|
radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
|
|
unsigned long first_index, unsigned int max_items,
|
|
unsigned int tag);
|
|
int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag);
|
|
|
|
static inline void radix_tree_preload_end(void)
|
|
{
|
|
preempt_enable();
|
|
}
|
|
|
|
#endif /* _LINUX_RADIX_TREE_H */
|