diff options
Diffstat (limited to 'drivers/staging/zram/xvmalloc.c')
-rw-r--r-- | drivers/staging/zram/xvmalloc.c | 81 |
1 files changed, 38 insertions, 43 deletions
diff --git a/drivers/staging/zram/xvmalloc.c b/drivers/staging/zram/xvmalloc.c index b644067..ae0623a 100644 --- a/drivers/staging/zram/xvmalloc.c +++ b/drivers/staging/zram/xvmalloc.c @@ -10,6 +10,10 @@ * Released under the terms of GNU General Public License Version 2.0 */ +#ifdef CONFIG_ZRAM_DEBUG +#define DEBUG +#endif + #include <linux/bitops.h> #include <linux/errno.h> #include <linux/highmem.h> @@ -46,7 +50,7 @@ static void clear_flag(struct block_header *block, enum blockflags flag) } /* - * Given <page, offset> pair, provide a derefrencable pointer. + * Given <page, offset> pair, provide a dereferencable pointer. * This is called from xv_malloc/xv_free path, so it * needs to be fast. */ @@ -200,6 +204,8 @@ static void insert_block(struct xv_pool *pool, struct page *page, u32 offset, nextblock->link.prev_page = page; nextblock->link.prev_offset = offset; put_ptr_atomic(nextblock, KM_USER1); + /* If there was a next page then the free bits are set. */ + return; } __set_bit(slindex % BITS_PER_LONG, &pool->slbitmap[flindex]); @@ -207,54 +213,14 @@ static void insert_block(struct xv_pool *pool, struct page *page, u32 offset, } /* - * Remove block from head of freelist. Index 'slindex' identifies the freelist. - */ -static void remove_block_head(struct xv_pool *pool, - struct block_header *block, u32 slindex) -{ - struct block_header *tmpblock; - u32 flindex = slindex / BITS_PER_LONG; - - pool->freelist[slindex].page = block->link.next_page; - pool->freelist[slindex].offset = block->link.next_offset; - block->link.prev_page = NULL; - block->link.prev_offset = 0; - - if (!pool->freelist[slindex].page) { - __clear_bit(slindex % BITS_PER_LONG, &pool->slbitmap[flindex]); - if (!pool->slbitmap[flindex]) - __clear_bit(flindex, &pool->flbitmap); - } else { - /* - * DEBUG ONLY: We need not reinitialize freelist head previous - * pointer to 0 - we never depend on its value. But just for - * sanity, lets do it. - */ - tmpblock = get_ptr_atomic(pool->freelist[slindex].page, - pool->freelist[slindex].offset, KM_USER1); - tmpblock->link.prev_page = NULL; - tmpblock->link.prev_offset = 0; - put_ptr_atomic(tmpblock, KM_USER1); - } -} - -/* * Remove block from freelist. Index 'slindex' identifies the freelist. */ static void remove_block(struct xv_pool *pool, struct page *page, u32 offset, struct block_header *block, u32 slindex) { - u32 flindex; + u32 flindex = slindex / BITS_PER_LONG; struct block_header *tmpblock; - if (pool->freelist[slindex].page == page - && pool->freelist[slindex].offset == offset) { - remove_block_head(pool, block, slindex); - return; - } - - flindex = slindex / BITS_PER_LONG; - if (block->link.prev_page) { tmpblock = get_ptr_atomic(block->link.prev_page, block->link.prev_offset, KM_USER1); @@ -270,6 +236,35 @@ static void remove_block(struct xv_pool *pool, struct page *page, u32 offset, tmpblock->link.prev_offset = block->link.prev_offset; put_ptr_atomic(tmpblock, KM_USER1); } + + /* Is this block is at the head of the freelist? */ + if (pool->freelist[slindex].page == page + && pool->freelist[slindex].offset == offset) { + + pool->freelist[slindex].page = block->link.next_page; + pool->freelist[slindex].offset = block->link.next_offset; + + if (pool->freelist[slindex].page) { + struct block_header *tmpblock; + tmpblock = get_ptr_atomic(pool->freelist[slindex].page, + pool->freelist[slindex].offset, + KM_USER1); + tmpblock->link.prev_page = NULL; + tmpblock->link.prev_offset = 0; + put_ptr_atomic(tmpblock, KM_USER1); + } else { + /* This freelist bucket is empty */ + __clear_bit(slindex % BITS_PER_LONG, + &pool->slbitmap[flindex]); + if (!pool->slbitmap[flindex]) + __clear_bit(flindex, &pool->flbitmap); + } + } + + block->link.prev_page = NULL; + block->link.prev_offset = 0; + block->link.next_page = NULL; + block->link.next_offset = 0; } /* @@ -378,7 +373,7 @@ int xv_malloc(struct xv_pool *pool, u32 size, struct page **page, block = get_ptr_atomic(*page, *offset, KM_USER0); - remove_block_head(pool, block, index); + remove_block(pool, *page, *offset, block, index); /* Split the block if required */ tmpoffset = *offset + size + XV_ALIGN; |