From 929f97276bcf7f4a95272ed08a85339b98ba210d Mon Sep 17 00:00:00 2001 From: Dean Nelson Date: Fri, 23 Jun 2006 02:03:21 -0700 Subject: [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 Cc: Andrey Volkov Acked-by: Jes Sorensen Cc: "Luck, Tony" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/genalloc.h | 35 +++++++++++++++-------------------- 1 file changed, 15 insertions(+), 20 deletions(-) (limited to 'include/linux/genalloc.h') 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 @@ * Uses for this includes on-device special memory, uncached memory * etc. * - * This code is based on the buddy allocator found in the sym53c8xx_2 - * driver, adapted for general purpose use. - * * This source code is licensed under the GNU General Public License, * Version 2. See the file COPYING for more details. */ -#include -#define ALLOC_MIN_SHIFT 5 /* 32 bytes minimum */ /* - * Link between free memory chunks of a given size. + * General purpose special memory pool descriptor. */ -struct gen_pool_link { - struct gen_pool_link *next; +struct gen_pool { + rwlock_t lock; + struct list_head chunks; /* list of chunks in this pool */ + int min_alloc_order; /* minimum allocation order */ }; /* - * Memory pool descriptor. + * General purpose special memory pool chunk descriptor. */ -struct gen_pool { +struct gen_pool_chunk { spinlock_t lock; - unsigned long (*get_new_chunk)(struct gen_pool *); - struct gen_pool *next; - struct gen_pool_link *h; - unsigned long private; - int max_chunk_shift; + struct list_head next_chunk; /* next chunk in pool */ + unsigned long start_addr; /* starting address of memory chunk */ + unsigned long end_addr; /* ending address of memory chunk */ + unsigned long bits[0]; /* bitmap for allocating memory chunk */ }; -unsigned long gen_pool_alloc(struct gen_pool *poolp, int size); -void gen_pool_free(struct gen_pool *mp, unsigned long ptr, int size); -struct gen_pool *gen_pool_create(int nr_chunks, int max_chunk_shift, - unsigned long (*fp)(struct gen_pool *), - unsigned long data); +extern struct gen_pool *gen_pool_create(int, int); +extern int gen_pool_add(struct gen_pool *, unsigned long, size_t, int); +extern unsigned long gen_pool_alloc(struct gen_pool *, size_t); +extern void gen_pool_free(struct gen_pool *, unsigned long, size_t); -- cgit v1.2.3-59-g8ed1b