Hi Xiu,
On Mon, Aug 7, 2023 at 7:49 PM Xiu Jianfeng <xiujianfeng@xxxxxxxxxxxxxxx> wrote:
>
> From: Xiu Jianfeng <xiujianfeng@xxxxxxxxxx>
>
> Since commit 0bb488498c98 ("mm: zswap: remove zswap_header"), the
> 'offset' has been replaced by swpentry, update the comment for it,
> and also add comment for 'objcg'.
>
> Signed-off-by: Xiu Jianfeng <xiujianfeng@xxxxxxxxxx>
> ---
> mm/zswap.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/mm/zswap.c b/mm/zswap.c
> index 5b56d38e7339..d7863c139c82 100644
> --- a/mm/zswap.c
> +++ b/mm/zswap.c
> @@ -182,7 +182,7 @@ struct zswap_pool {
> * page within zswap.
> *
> * rbnode - links the entry into red-black tree for the appropriate swap type
> - * offset - the swap offset for the entry. Index into the red-black tree.
> + * swpentry - the swap entry for the entry, include 'type' and 'offset' fields
This is not the place to document that a swap entry has 'type' and
'offset' fields.
I would also avoid the repetitive 'entry'. Maybe something like:
swpentry - associated swap entry, the offset indexes into the red-black tree
>
> * refcount - the number of outstanding reference to the entry. This is needed
> * to protect against premature freeing of the entry by code
> * concurrent calls to load, invalidate, and writeback. The lock
> @@ -195,6 +195,7 @@ struct zswap_pool {
> * pool - the zswap_pool the entry's data is in
> * handle - zpool allocation handle that stores the compressed page data
> * value - value of the same-value filled pages which have same content
> + * objcg - the obj_cgroup(actually memcg) this entry belongs to
Again, not the place to document that objcg is an abstraction layer
above a memcg.
I would do something like:
objcg - the obj_cgroup that the compressed memory is charged to
>
> * lru - handle to the pool's lru used to evict pages.
> */
> struct zswap_entry {
> --
> 2.34.1
>
>
