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authorDean Nelson <dcn@sgi.com>2006-06-23 05:03:21 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-23 10:42:49 -0400
commit929f97276bcf7f4a95272ed08a85339b98ba210d (patch)
tree4975698af9559279c83e4e268213ed13e3efee9a /include/linux/genalloc.h
parent833423143c3a7c6545e409d65febd0d92deb351b (diff)
[PATCH] change gen_pool allocator to not touch managed memory
Modify the gen_pool allocator (lib/genalloc.c) to utilize a bitmap scheme instead of the buddy scheme. The purpose of this change is to eliminate the touching of the actual memory being allocated. Since the change modifies the interface, a change to the uncached allocator (arch/ia64/kernel/uncached.c) is also required. Both Andrey Volkov and Jes Sorenson have expressed a desire that the gen_pool allocator not write to the memory being managed. See the following: http://marc.theaimsgroup.com/?l=linux-kernel&m=113518602713125&w=2 http://marc.theaimsgroup.com/?l=linux-kernel&m=113533568827916&w=2 Signed-off-by: Dean Nelson <dcn@sgi.com> Cc: Andrey Volkov <avolkov@varma-el.com> Acked-by: Jes Sorensen <jes@trained-monkey.org> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux/genalloc.h')
-rw-r--r--include/linux/genalloc.h35
1 files changed, 15 insertions, 20 deletions
diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
index 7fd0576a4454..690c42803d2e 100644
--- a/include/linux/genalloc.h
+++ b/include/linux/genalloc.h
@@ -4,37 +4,32 @@
4 * Uses for this includes on-device special memory, uncached memory 4 * Uses for this includes on-device special memory, uncached memory
5 * etc. 5 * etc.
6 * 6 *
7 * This code is based on the buddy allocator found in the sym53c8xx_2
8 * driver, adapted for general purpose use.
9 *
10 * This source code is licensed under the GNU General Public License, 7 * This source code is licensed under the GNU General Public License,
11 * Version 2. See the file COPYING for more details. 8 * Version 2. See the file COPYING for more details.
12 */ 9 */
13 10
14#include <linux/spinlock.h>
15 11
16#define ALLOC_MIN_SHIFT 5 /* 32 bytes minimum */
17/* 12/*
18 * Link between free memory chunks of a given size. 13 * General purpose special memory pool descriptor.
19 */ 14 */
20struct gen_pool_link { 15struct gen_pool {
21 struct gen_pool_link *next; 16 rwlock_t lock;
17 struct list_head chunks; /* list of chunks in this pool */
18 int min_alloc_order; /* minimum allocation order */
22}; 19};
23 20
24/* 21/*
25 * Memory pool descriptor. 22 * General purpose special memory pool chunk descriptor.
26 */ 23 */
27struct gen_pool { 24struct gen_pool_chunk {
28 spinlock_t lock; 25 spinlock_t lock;
29 unsigned long (*get_new_chunk)(struct gen_pool *); 26 struct list_head next_chunk; /* next chunk in pool */
30 struct gen_pool *next; 27 unsigned long start_addr; /* starting address of memory chunk */
31 struct gen_pool_link *h; 28 unsigned long end_addr; /* ending address of memory chunk */
32 unsigned long private; 29 unsigned long bits[0]; /* bitmap for allocating memory chunk */
33 int max_chunk_shift;
34}; 30};
35 31
36unsigned long gen_pool_alloc(struct gen_pool *poolp, int size); 32extern struct gen_pool *gen_pool_create(int, int);
37void gen_pool_free(struct gen_pool *mp, unsigned long ptr, int size); 33extern int gen_pool_add(struct gen_pool *, unsigned long, size_t, int);
38struct gen_pool *gen_pool_create(int nr_chunks, int max_chunk_shift, 34extern unsigned long gen_pool_alloc(struct gen_pool *, size_t);
39 unsigned long (*fp)(struct gen_pool *), 35extern void gen_pool_free(struct gen_pool *, unsigned long, size_t);
40 unsigned long data);