On Fri, Dec 06, 2024 at 01:35:11AM +0000, Chen Ridong wrote:
> From: Chen Ridong <chenridong@xxxxxxxxxx>
>
> Factor out the '__refill_obj_stock' function to make the code more
> cohesive.
>
> Signed-off-by: Chen Ridong <chenridong@xxxxxxxxxx>
> ---
> mm/memcontrol.c | 31 ++++++++++++++++++-------------
> 1 file changed, 18 insertions(+), 13 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index f977e0be1c04..0c9331d7b606 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -2697,6 +2697,21 @@ void __memcg_kmem_uncharge_page(struct page *page, int order)
> obj_cgroup_put(objcg);
> }
>
> +/* If the cached_objcg was refilled, return true; otherwise, return false */
> +static bool __refill_obj_stock(struct memcg_stock_pcp *stock,
> + struct obj_cgroup *objcg, struct obj_cgroup **old_objcg)
> +{
> + if (READ_ONCE(stock->cached_objcg) != objcg) {
Keep the above check in the calling functions and make this a void
function. Also I think we need a better name.
> + *old_objcg = drain_obj_stock(stock);
> + obj_cgroup_get(objcg);
> + stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes)
> + ? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0;
> + WRITE_ONCE(stock->cached_objcg, objcg);
> + return true;
> + }
> + return false;
> +}
> +
> static void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
> enum node_stat_item idx, int nr)
> {
> @@ -2713,12 +2728,7 @@ static void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
> * accumulating over a page of vmstat data or when pgdat or idx
> * changes.
> */
> - if (READ_ONCE(stock->cached_objcg) != objcg) {
> - old = drain_obj_stock(stock);
> - obj_cgroup_get(objcg);
> - stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes)
> - ? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0;
> - WRITE_ONCE(stock->cached_objcg, objcg);
> + if (__refill_obj_stock(stock, objcg, &old)) {
> stock->cached_pgdat = pgdat;
> } else if (stock->cached_pgdat != pgdat) {
> /* Flush the existing cached vmstat data */
> @@ -2871,14 +2881,9 @@ static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes,
> local_lock_irqsave(&memcg_stock.stock_lock, flags);
>
> stock = this_cpu_ptr(&memcg_stock);
> - if (READ_ONCE(stock->cached_objcg) != objcg) { /* reset if necessary */
> - old = drain_obj_stock(stock);
> - obj_cgroup_get(objcg);
> - WRITE_ONCE(stock->cached_objcg, objcg);
> - stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes)
> - ? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0;
> + if (__refill_obj_stock(stock, objcg, &old))
> allow_uncharge = true; /* Allow uncharge when objcg changes */
> - }
> +
> stock->nr_bytes += nr_bytes;
>
> if (allow_uncharge && (stock->nr_bytes > PAGE_SIZE)) {
> --
> 2.34.1
>
