From 7c8545e98468c53809fc06788a3b9a34dff05240 Mon Sep 17 00:00:00 2001 From: Li Yang Date: Mon, 18 Jun 2007 19:29:21 +0800 Subject: [PATCH] [POWERPC] rheap - eliminates internal fragments caused by alignment The patch adds fragments caused by rh_alloc_align() back to free list, instead of allocating the whole chunk of memory. This will greatly improve memory utilization managed by rheap. It solves MURAM not enough problem with 3 UCCs enabled on MPC8323. Signed-off-by: Li Yang Acked-by: Joakim Tjernlund Signed-off-by: Kumar Gala --- arch/powerpc/lib/rheap.c | 48 ++++++++++++++++++++++++---------------- 1 file changed, 29 insertions(+), 19 deletions(-) diff --git a/arch/powerpc/lib/rheap.c b/arch/powerpc/lib/rheap.c index 180ee2933a..2f24ea0d72 100644 --- a/arch/powerpc/lib/rheap.c +++ b/arch/powerpc/lib/rheap.c @@ -437,27 +437,26 @@ unsigned long rh_alloc_align(rh_info_t * info, int size, int alignment, const ch struct list_head *l; rh_block_t *blk; rh_block_t *newblk; - unsigned long start; + unsigned long start, sp_size; /* Validate size, and alignment must be power of two */ if (size <= 0 || (alignment & (alignment - 1)) != 0) return (unsigned long) -EINVAL; - /* given alignment larger that default rheap alignment */ - if (alignment > info->alignment) - size += alignment - 1; - /* Align to configured alignment */ size = (size + (info->alignment - 1)) & ~(info->alignment - 1); - if (assure_empty(info, 1) < 0) + if (assure_empty(info, 2) < 0) return (unsigned long) -ENOMEM; blk = NULL; list_for_each(l, &info->free_list) { blk = list_entry(l, rh_block_t, list); - if (size <= blk->size) - break; + if (size <= blk->size) { + start = (blk->start + alignment - 1) & ~(alignment - 1); + if (start + size <= blk->start + blk->size) + break; + } blk = NULL; } @@ -470,25 +469,36 @@ unsigned long rh_alloc_align(rh_info_t * info, int size, int alignment, const ch list_del(&blk->list); newblk = blk; } else { + /* Fragment caused, split if needed */ + /* Create block for fragment in the beginning */ + sp_size = start - blk->start; + if (sp_size) { + rh_block_t *spblk; + + spblk = get_slot(info); + spblk->start = blk->start; + spblk->size = sp_size; + /* add before the blk */ + list_add(&spblk->list, blk->list.prev); + } newblk = get_slot(info); - newblk->start = blk->start; + newblk->start = start; newblk->size = size; - /* blk still in free list, with updated start, size */ - blk->start += size; - blk->size -= size; + /* blk still in free list, with updated start and size + * for fragment in the end */ + blk->start = start + size; + blk->size -= sp_size + size; + /* No fragment in the end, remove blk */ + if (blk->size == 0) { + list_del(&blk->list); + release_slot(info, blk); + } } newblk->owner = owner; - start = newblk->start; attach_taken_block(info, newblk); - /* for larger alignment return fixed up pointer */ - /* this is no problem with the deallocator since */ - /* we scan for pointers that lie in the blocks */ - if (alignment > info->alignment) - start = (start + alignment - 1) & ~(alignment - 1); - return start; } -- 2.39.5