On Thu 17-02-22 10:48:01, Sebastian Andrzej Siewior wrote:
> From: Johannes Weiner <hannes@xxxxxxxxxxx>
>
> Provide the inner part of refill_stock() as __refill_stock() without
> disabling interrupts. This eases the integration of local_lock_t where
> recursive locking must be avoided.
> Open code obj_cgroup_uncharge_pages() in drain_obj_stock() and use
> __refill_stock(). The caller of drain_obj_stock() already disables
> interrupts.
>
> [bigeasy: Patch body around Johannes' diff ]
>
> Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Thanks!
> ---
> mm/memcontrol.c | 24 ++++++++++++++++++------
> 1 file changed, 18 insertions(+), 6 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 36ab3660f2c6d..a3225501cce36 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -2224,12 +2224,9 @@ static void drain_local_stock(struct work_struct *dummy)
> * Cache charges(val) to local per_cpu area.
> * This will be consumed by consume_stock() function, later.
> */
> -static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
> +static void __refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
> {
> struct memcg_stock_pcp *stock;
> - unsigned long flags;
> -
> - local_irq_save(flags);
>
> stock = this_cpu_ptr(&memcg_stock);
> if (stock->cached != memcg) { /* reset if necessary */
> @@ -2241,7 +2238,14 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
>
> if (stock->nr_pages > MEMCG_CHARGE_BATCH)
> drain_stock(stock);
> +}
>
> +static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
> +{
> + unsigned long flags;
> +
> + local_irq_save(flags);
> + __refill_stock(memcg, nr_pages);
> local_irq_restore(flags);
> }
>
> @@ -3158,8 +3162,16 @@ static void drain_obj_stock(struct memcg_stock_pcp *stock)
> unsigned int nr_pages = stock->nr_bytes >> PAGE_SHIFT;
> unsigned int nr_bytes = stock->nr_bytes & (PAGE_SIZE - 1);
>
> - if (nr_pages)
> - obj_cgroup_uncharge_pages(old, nr_pages);
> + if (nr_pages) {
> + struct mem_cgroup *memcg;
> +
> + memcg = get_mem_cgroup_from_objcg(old);
> +
> + memcg_account_kmem(memcg, -nr_pages);
> + __refill_stock(memcg, nr_pages);
> +
> + css_put(&memcg->css);
> + }
>
> /*
> * The leftover is flushed to the centralized per-memcg value.
> --
> 2.34.1
--
Michal Hocko
SUSE Labs
