[PATCH 1/3] staging: zcache: xcfmalloc memory allocator for zcache
Seth Jennings
sjenning at linux.vnet.ibm.com
Thu Sep 1 15:43:27 UTC 2011
On 08/31/2011 09:40 AM, Seth Jennings wrote:
> +static struct xcf_blkdesc *xcf_find_remove_block(struct xcf_pool *pool,
> + int size, int blocknum)
> +{
> + int flindex, i;
> + struct xcf_blkdesc *desc = NULL;
> +
> + flindex = xcf_size_to_flindex(size + sizeof(struct xcf_blkhdr));
> +
> + /* look for best fit */
> + if (pool->freelists[flindex])
> + goto remove;
> +
> + /* if this is the last block allowed in the allocation, we shouldn't
> + * consider smaller blocks. it's all or nothing now */
> + if (blocknum == XCF_MAX_BLOCKS_PER_ALLOC) {
In gathering my performance numbers for Dan, I discovered I introduced
a regression by making a late change in my development.
This line should be:
if (blocknum != XCF_MAX_BLOCKS_PER_ALLOC) {
This regression actually causes xcfmalloc to have the same fragmentation
issue as xvmalloc.
> + /* look for largest smaller block */
> + for (i = flindex; i > 0; i--) {
> + if (pool->freelists[i]) {
> + flindex = i;
> + goto remove;
> + }
> + }
> + }
--
Seth
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