From 72e80b89015bab196f0f0e83b12b0eee75fa0574 Mon Sep 17 00:00:00 2001 From: Alberto Garcia Date: Mon, 11 May 2015 15:54:53 +0300 Subject: qcow2: use one single memory block for the L2/refcount cache tables The qcow2 L2/refcount cache contains one separate table for each cache entry. Doing one allocation per table adds unnecessary overhead and it also requires us to store the address of each table separately. Since the size of the cache is constant during its lifetime, it's better to have an array that contains all the tables using one single allocation. In my tests measuring freshly created caches with sizes 128MB (L2) and 32MB (refcount) this uses around 10MB of RAM less. Signed-off-by: Alberto Garcia Reviewed-by: Stefan Hajnoczi Reviewed-by: Max Reitz Signed-off-by: Kevin Wolf --- block/qcow2-refcount.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'block/qcow2-refcount.c') diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 83467c31c3..0707f94206 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -424,7 +424,7 @@ static int alloc_refcount_block(BlockDriverState *bs, /* Now the new refcount block needs to be written to disk */ BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE); - qcow2_cache_entry_mark_dirty(s->refcount_block_cache, *refcount_block); + qcow2_cache_entry_mark_dirty(bs, s->refcount_block_cache, *refcount_block); ret = qcow2_cache_flush(bs, s->refcount_block_cache); if (ret < 0) { goto fail_block; @@ -737,7 +737,8 @@ static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, } old_table_index = table_index; - qcow2_cache_entry_mark_dirty(s->refcount_block_cache, refcount_block); + qcow2_cache_entry_mark_dirty(bs, s->refcount_block_cache, + refcount_block); /* we can update the count and save it */ block_index = cluster_index & (s->refcount_block_size - 1); @@ -1182,7 +1183,8 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs, s->refcount_block_cache); } l2_table[j] = cpu_to_be64(offset); - qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table); + qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, + l2_table); } } -- cgit v1.2.3