* Re: [PATCH] mm: memcontrol: factor out memcg kmem uncharge sequence
2026-07-13 9:03 [PATCH] mm: memcontrol: factor out memcg kmem uncharge sequence Guopeng Zhang
@ 2026-07-13 10:24 ` Tao Cui
2026-07-13 10:25 ` Tao Cui
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Tao Cui @ 2026-07-13 10:24 UTC (permalink / raw)
To: Guopeng Zhang, Andrew Morton, Roman Gushchin
Cc: cui.tao, Johannes Weiner, Michal Hocko, Shakeel Butt, Muchun Song,
cgroups, linux-mm, linux-kernel, Guopeng Zhang
在 2026/7/13 17:03, Guopeng Zhang 写道:
> From: Guopeng Zhang <zhangguopeng@kylinos.cn>
>
> The kmem-uncharge sequence (mod_memcg_state(MEMCG_KMEM) +
> memcg1_account_kmem + conditional memcg_uncharge) is duplicated verbatim
> in obj_cgroup_release() and drain_obj_stock_slot(). Factor it into a
> small memcg_uncharge_kmem() helper. The reference get/put stays at the
> call sites, as they differ.
>
> No functional change.
Acked-by: Tao Cui <cuitao@kylinos.cn>
>
> Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
> ---
> mm/memcontrol.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 22f55aeb94f3..86acfe55a201 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -137,6 +137,14 @@ bool mem_cgroup_kmem_disabled(void)
>
> static void memcg_uncharge(struct mem_cgroup *memcg, unsigned int nr_pages);
>
> +static void memcg_uncharge_kmem(struct mem_cgroup *memcg, unsigned int nr_pages)
> +{
> + mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages);
> + memcg1_account_kmem(memcg, -nr_pages);
> + if (!mem_cgroup_is_root(memcg))
> + memcg_uncharge(memcg, nr_pages);
> +}
> +
> static void obj_cgroup_release(struct percpu_ref *ref)
> {
> struct obj_cgroup *objcg = container_of(ref, struct obj_cgroup, refcnt);
> @@ -172,10 +180,7 @@ static void obj_cgroup_release(struct percpu_ref *ref)
> struct mem_cgroup *memcg;
>
> memcg = get_mem_cgroup_from_objcg(objcg);
> - mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages);
> - memcg1_account_kmem(memcg, -nr_pages);
> - if (!mem_cgroup_is_root(memcg))
> - memcg_uncharge(memcg, nr_pages);
> + memcg_uncharge_kmem(memcg, nr_pages);
> mem_cgroup_put(memcg);
> }
>
> @@ -3329,10 +3334,7 @@ static void drain_obj_stock_slot(struct obj_stock_pcp *stock, int i)
>
> memcg = get_mem_cgroup_from_objcg(old);
>
> - mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages);
> - memcg1_account_kmem(memcg, -nr_pages);
> - if (!mem_cgroup_is_root(memcg))
> - memcg_uncharge(memcg, nr_pages);
> + memcg_uncharge_kmem(memcg, nr_pages);
>
> css_put(&memcg->css);
> }
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] mm: memcontrol: factor out memcg kmem uncharge sequence
2026-07-13 9:03 [PATCH] mm: memcontrol: factor out memcg kmem uncharge sequence Guopeng Zhang
2026-07-13 10:24 ` Tao Cui
@ 2026-07-13 10:25 ` Tao Cui
2026-07-13 11:42 ` Johannes Weiner
2026-07-13 12:33 ` Muchun Song
3 siblings, 0 replies; 5+ messages in thread
From: Tao Cui @ 2026-07-13 10:25 UTC (permalink / raw)
To: Guopeng Zhang, Andrew Morton, Roman Gushchin
Cc: cui.tao, Johannes Weiner, Michal Hocko, Shakeel Butt, Muchun Song,
cgroups, linux-mm, linux-kernel, Guopeng Zhang
在 2026/7/13 17:03, Guopeng Zhang 写道:
> From: Guopeng Zhang <zhangguopeng@kylinos.cn>
>
> The kmem-uncharge sequence (mod_memcg_state(MEMCG_KMEM) +
> memcg1_account_kmem + conditional memcg_uncharge) is duplicated verbatim
> in obj_cgroup_release() and drain_obj_stock_slot(). Factor it into a
> small memcg_uncharge_kmem() helper. The reference get/put stays at the
> call sites, as they differ.
>
> No functional change.
Acked-by: Tao Cui <cuitao@kylinos.cn>
>
> Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
> ---
> mm/memcontrol.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 22f55aeb94f3..86acfe55a201 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -137,6 +137,14 @@ bool mem_cgroup_kmem_disabled(void)
>
> static void memcg_uncharge(struct mem_cgroup *memcg, unsigned int nr_pages);
>
> +static void memcg_uncharge_kmem(struct mem_cgroup *memcg, unsigned int nr_pages)
> +{
> + mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages);
> + memcg1_account_kmem(memcg, -nr_pages);
> + if (!mem_cgroup_is_root(memcg))
> + memcg_uncharge(memcg, nr_pages);
> +}
> +
> static void obj_cgroup_release(struct percpu_ref *ref)
> {
> struct obj_cgroup *objcg = container_of(ref, struct obj_cgroup, refcnt);
> @@ -172,10 +180,7 @@ static void obj_cgroup_release(struct percpu_ref *ref)
> struct mem_cgroup *memcg;
>
> memcg = get_mem_cgroup_from_objcg(objcg);
> - mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages);
> - memcg1_account_kmem(memcg, -nr_pages);
> - if (!mem_cgroup_is_root(memcg))
> - memcg_uncharge(memcg, nr_pages);
> + memcg_uncharge_kmem(memcg, nr_pages);
> mem_cgroup_put(memcg);
> }
>
> @@ -3329,10 +3334,7 @@ static void drain_obj_stock_slot(struct obj_stock_pcp *stock, int i)
>
> memcg = get_mem_cgroup_from_objcg(old);
>
> - mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages);
> - memcg1_account_kmem(memcg, -nr_pages);
> - if (!mem_cgroup_is_root(memcg))
> - memcg_uncharge(memcg, nr_pages);
> + memcg_uncharge_kmem(memcg, nr_pages);
>
> css_put(&memcg->css);
> }
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] mm: memcontrol: factor out memcg kmem uncharge sequence
2026-07-13 9:03 [PATCH] mm: memcontrol: factor out memcg kmem uncharge sequence Guopeng Zhang
2026-07-13 10:24 ` Tao Cui
2026-07-13 10:25 ` Tao Cui
@ 2026-07-13 11:42 ` Johannes Weiner
2026-07-13 12:33 ` Muchun Song
3 siblings, 0 replies; 5+ messages in thread
From: Johannes Weiner @ 2026-07-13 11:42 UTC (permalink / raw)
To: Guopeng Zhang
Cc: Andrew Morton, Roman Gushchin, Michal Hocko, Shakeel Butt,
Muchun Song, cgroups, linux-mm, linux-kernel, Guopeng Zhang
On Mon, Jul 13, 2026 at 05:03:04PM +0800, Guopeng Zhang wrote:
> From: Guopeng Zhang <zhangguopeng@kylinos.cn>
>
> The kmem-uncharge sequence (mod_memcg_state(MEMCG_KMEM) +
> memcg1_account_kmem + conditional memcg_uncharge) is duplicated verbatim
> in obj_cgroup_release() and drain_obj_stock_slot(). Factor it into a
> small memcg_uncharge_kmem() helper. The reference get/put stays at the
> call sites, as they differ.
>
> No functional change.
>
> Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] mm: memcontrol: factor out memcg kmem uncharge sequence
2026-07-13 9:03 [PATCH] mm: memcontrol: factor out memcg kmem uncharge sequence Guopeng Zhang
` (2 preceding siblings ...)
2026-07-13 11:42 ` Johannes Weiner
@ 2026-07-13 12:33 ` Muchun Song
3 siblings, 0 replies; 5+ messages in thread
From: Muchun Song @ 2026-07-13 12:33 UTC (permalink / raw)
To: Guopeng Zhang
Cc: Andrew Morton, Roman Gushchin, Johannes Weiner, Michal Hocko,
Shakeel Butt, cgroups, linux-mm, linux-kernel, Guopeng Zhang
> On Jul 13, 2026, at 17:03, Guopeng Zhang <guopeng.zhang@linux.dev> wrote:
>
> From: Guopeng Zhang <zhangguopeng@kylinos.cn>
>
> The kmem-uncharge sequence (mod_memcg_state(MEMCG_KMEM) +
> memcg1_account_kmem + conditional memcg_uncharge) is duplicated verbatim
> in obj_cgroup_release() and drain_obj_stock_slot(). Factor it into a
> small memcg_uncharge_kmem() helper. The reference get/put stays at the
> call sites, as they differ.
>
> No functional change.
>
> Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
^ permalink raw reply [flat|nested] 5+ messages in thread