On Thu, Aug 2, 2018 at 10:58 PM, Tony Battersby <tonyb@xxxxxxxxxxxxxxx> wrote:
> dma_pool_alloc() scales poorly when allocating a large number of pages
> because it does a linear scan of all previously-allocated pages before
> allocating a new one. Improve its scalability by maintaining a separate
> list of pages that have free blocks ready to (re)allocate. In big O
> notation, this improves the algorithm from O(n^2) to O(n).
> struct dma_pool { /* the pool */
> +#define POOL_FULL_IDX 0
> +#define POOL_AVAIL_IDX 1
> +#define POOL_N_LISTS 2
> + struct list_head page_list[POOL_N_LISTS];
To be consistent with naming scheme and common practice I would rather
name the last one as
POOL_MAX_IDX 2
> + INIT_LIST_HEAD(&retval->page_list[0]);
> + INIT_LIST_HEAD(&retval->page_list[1]);
You introduced defines and don't use them.
--
With Best Regards,
Andy Shevchenko
