On Thu, Nov 17, 2022 at 08:38:38AM -0800, Nhat Pham wrote:
> This adds fields to zs_pool to store evict handlers for writeback,
> analogous to the zbud allocator.
>
> Signed-off-by: Nhat Pham <nphamcs@xxxxxxxxx>
> ---
> mm/zsmalloc.c | 35 ++++++++++++++++++++++++++++++++++-
> 1 file changed, 34 insertions(+), 1 deletion(-)
>
> diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> index 2557b55ec767..776d0e15a401 100644
> --- a/mm/zsmalloc.c
> +++ b/mm/zsmalloc.c
> @@ -225,6 +225,12 @@ struct link_free {
> };
> };
>
> +struct zs_pool;
> +
> +struct zs_ops {
> + int (*evict)(struct zs_pool *pool, unsigned long handle);
> +};
> +
> struct zs_pool {
> const char *name;
>
> @@ -242,6 +248,9 @@ struct zs_pool {
> #ifdef CONFIG_ZPOOL
> /* List tracking the zspages in LRU order by most recently added object */
> struct list_head lru;
> + const struct zs_ops *ops;
> + struct zpool *zpool;
> + const struct zpool_ops *zpool_ops;
> #endif
>
> #ifdef CONFIG_ZSMALLOC_STAT
> @@ -385,6 +394,18 @@ static void record_obj(unsigned long handle, unsigned long obj)
>
> #ifdef CONFIG_ZPOOL
>
> +static int zs_zpool_evict(struct zs_pool *pool, unsigned long handle)
> +{
> + if (pool->zpool && pool->zpool_ops && pool->zpool_ops->evict)
> + return pool->zpool_ops->evict(pool->zpool, handle);
> + else
> + return -ENOENT;
> +}
> +
> +static const struct zs_ops zs_zpool_ops = {
> + .evict = zs_zpool_evict
> +};
> +
> static void *zs_zpool_create(const char *name, gfp_t gfp,
> const struct zpool_ops *zpool_ops,
> struct zpool *zpool)
> @@ -394,7 +415,19 @@ static void *zs_zpool_create(const char *name, gfp_t gfp,
> * different contexts and its caller must provide a valid
> * gfp mask.
> */
> - return zs_create_pool(name);
> + struct zs_pool *pool = zs_create_pool(name);
> +
> + if (pool) {
> + pool->zpool = zpool;
> + pool->zpool_ops = zpool_ops;
> +
> + if (zpool_ops)
I lost. When do we have zpool_ops as NULL?
