On Mon, 26 Jan 2015, Vladimir Davydov wrote:

> SLUB's kmem_cache_shrink not only removes empty slabs from the cache,
> but also sorts slabs by the number of objects in-use to cope with
> fragmentation. To achieve that, it tries to allocate a temporary array.
> If it fails, it will abort the whole procedure.

I do not think its worth optimizing this. If we cannot allocate even a
small object then the system is in an extremely bad state anyways.

> @@ -3400,7 +3407,9 @@ int __kmem_cache_shrink(struct kmem_cache *s)
>                * list_lock. page->inuse here is the upper limit.
>                */
>               list_for_each_entry_safe(page, t, &n->partial, lru) {
> -                     list_move(&page->lru, slabs_by_inuse + page->inuse);
> +                     if (page->inuse < objects)
> +                             list_move(&page->lru,
> +                                       slabs_by_inuse + page->inuse);
>                       if (!page->inuse)
>                               n->nr_partial--;
>               }

The condition is always true. A page that has page->inuse == objects
would not be on the partial list.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to