On Thu, Mar 03, 2016 at 11:46:00PM +0900, Sergey Senozhatsky wrote:
> Do not register shrinker compaction callbacks anymore, since
> now we shedule class compaction work each time its fragmentation
> value goes above the watermark.
I suggested to remove shrinker compaction but while I review your
first patch in this thread, I thought we need upper-bound to
compact zspage so background work can bail out for latency easily.
IOW, the work could give up the job. In such case, we might need
fall-back scheme to continue the job. And I think that could be
a shrinker.
What do you think?
>
> Signed-off-by: Sergey Senozhatsky <sergey.senozhat...@gmail.com>
> ---
> mm/zsmalloc.c | 72
> -----------------------------------------------------------
> 1 file changed, 72 deletions(-)
>
> diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> index a4ef7e7..0bb060f 100644
> --- a/mm/zsmalloc.c
> +++ b/mm/zsmalloc.c
> @@ -256,13 +256,6 @@ struct zs_pool {
>
> struct zs_pool_stats stats;
>
> - /* Compact classes */
> - struct shrinker shrinker;
> - /*
> - * To signify that register_shrinker() was successful
> - * and unregister_shrinker() will not Oops.
> - */
> - bool shrinker_enabled;
> #ifdef CONFIG_ZSMALLOC_STAT
> struct dentry *stat_dentry;
> #endif
> @@ -1848,64 +1841,6 @@ void zs_pool_stats(struct zs_pool *pool, struct
> zs_pool_stats *stats)
> }
> EXPORT_SYMBOL_GPL(zs_pool_stats);
>
> -static unsigned long zs_shrinker_scan(struct shrinker *shrinker,
> - struct shrink_control *sc)
> -{
> - unsigned long pages_freed;
> - struct zs_pool *pool = container_of(shrinker, struct zs_pool,
> - shrinker);
> -
> - pages_freed = pool->stats.pages_compacted;
> - /*
> - * Compact classes and calculate compaction delta.
> - * Can run concurrently with a manually triggered
> - * (by user) compaction.
> - */
> - pages_freed = zs_compact(pool) - pages_freed;
> -
> - return pages_freed ? pages_freed : SHRINK_STOP;
> -}
> -
> -static unsigned long zs_shrinker_count(struct shrinker *shrinker,
> - struct shrink_control *sc)
> -{
> - int i;
> - struct size_class *class;
> - unsigned long pages_to_free = 0;
> - struct zs_pool *pool = container_of(shrinker, struct zs_pool,
> - shrinker);
> -
> - for (i = zs_size_classes - 1; i >= 0; i--) {
> - class = pool->size_class[i];
> - if (!class)
> - continue;
> - if (class->index != i)
> - continue;
> -
> - pages_to_free += zs_can_compact(class);
> - }
> -
> - return pages_to_free;
> -}
> -
> -static void zs_unregister_shrinker(struct zs_pool *pool)
> -{
> - if (pool->shrinker_enabled) {
> - unregister_shrinker(&pool->shrinker);
> - pool->shrinker_enabled = false;
> - }
> -}
> -
> -static int zs_register_shrinker(struct zs_pool *pool)
> -{
> - pool->shrinker.scan_objects = zs_shrinker_scan;
> - pool->shrinker.count_objects = zs_shrinker_count;
> - pool->shrinker.batch = 0;
> - pool->shrinker.seeks = DEFAULT_SEEKS;
> -
> - return register_shrinker(&pool->shrinker);
> -}
> -
> /**
> * zs_create_pool - Creates an allocation pool to work from.
> * @flags: allocation flags used to allocate pool metadata
> @@ -1994,12 +1929,6 @@ struct zs_pool *zs_create_pool(const char *name, gfp_t
> flags)
> if (zs_pool_stat_create(name, pool))
> goto err;
>
> - /*
> - * Not critical, we still can use the pool
> - * and user can trigger compaction manually.
> - */
> - if (zs_register_shrinker(pool) == 0)
> - pool->shrinker_enabled = true;
> return pool;
>
> err:
> @@ -2012,7 +1941,6 @@ void zs_destroy_pool(struct zs_pool *pool)
> {
> int i;
>
> - zs_unregister_shrinker(pool);
> zs_pool_stat_destroy(pool);
>
> for (i = 0; i < zs_size_classes; i++) {
> --
> 2.8.0.rc0
>
