Re: [PATCH 3/6] nfsd: filecache: use list_lru_walk_node() in nfsd_file_gc()

Jeff Layton
2025-02-10T13:46:34Z

On Fri, 2025-02-07 at 16:15 +1100, NeilBrown wrote:
> list_lru_walk() is only useful when the aim is to remove all elements
> from the list_lru. It will repeated visit rotated element of the first
> per-node sublist before proceeding to subsrequent sublists.
>
> This patch changes to use list_lru_walk_node() and list_lru_count_node()
> on each individual node.
>
> Signed-off-by: NeilBrown <neilb@suse.de>
> ---
> fs/nfsd/filecache.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
> index 7dc20143c854..04588c03bdfe 100644
> --- a/fs/nfsd/filecache.c
> +++ b/fs/nfsd/filecache.c
> @@ -532,10 +532,14 @@ static void
> nfsd_file_gc(void)
> {
> LIST_HEAD(dispose);
> - unsigned long ret;
> + unsigned long ret = 0;
> + int nid;
>
> - ret = list_lru_walk(&nfsd_file_lru, nfsd_file_lru_cb,
> - &dispose, list_lru_count(&nfsd_file_lru));
> + for_each_node_state(nid, N_NORMAL_MEMORY) {
> + unsigned long nr = list_lru_count_node(&nfsd_file_lru, nid);
> + ret += list_lru_walk_node(&nfsd_file_lru, nid, nfsd_file_lru_cb,
> + &dispose, &nr);
> + }
> trace_nfsd_file_gc_removed(ret, list_lru_count(&nfsd_file_lru));
> nfsd_file_dispose_list_delayed(&dispose);
> }

It might be worthwhile to make this a generic helper in list_lru.h:

Reviewed-by: Jeff Layton <jlayton@kernel.org>