Re: [PATCH v2 05/12] fs: Propagate shrinker::id to list_lru

[Vladimir Davydov]

On Tue, Apr 17, 2018 at 09:53:47PM +0300, Kirill Tkhai wrote:
> The patch adds list_lru::shrinker_id field, and populates
> it by registered shrinker id.
> 
> This will be used to set correct bit in memcg shrinkers
> map by lru code in next patches, after there appeared
> the first related to memcg element in list_lru.
> 
> Signed-off-by: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx>
> ---
>  fs/super.c               |    4 +++-
>  include/linux/list_lru.h |    1 +
>  include/linux/shrinker.h |    8 +++++++-
>  mm/list_lru.c            |    6 ++++++
>  mm/vmscan.c              |   15 ++++++++++-----
>  mm/workingset.c          |    3 ++-
>  6 files changed, 29 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/super.c b/fs/super.c
> index 5fa9a8d8d865..9bc5698c8c3c 100644
> --- a/fs/super.c
> +++ b/fs/super.c
> @@ -518,7 +518,9 @@ struct super_block *sget_userns(struct file_system_type *type,
>  	hlist_add_head(&s->s_instances, &type->fs_supers);
>  	spin_unlock(&sb_lock);
>  	get_filesystem(type);
> -	err = register_shrinker(&s->s_shrink);
> +	err = register_shrinker_args(&s->s_shrink, 2,
> +				     &s->s_dentry_lru.shrinker_id,
> +				     &s->s_inode_lru.shrinker_id);

This looks ugly. May be, we could allocate an id in prealloc_shrinker
then simply pass it to list_lru_init in arguments?