Re: [PATCH] mm: memcontrol: make cgroup_memory_nokmem static

From: Vlastimil Babka
Date: Tue Nov 16 2021 - 12:27:25 EST


On 11/9/21 07:54, Muchun Song wrote:
> The commit 494c1dfe855e ("mm: memcg/slab: create a new set of kmalloc-cg-<n>
> caches") makes cgroup_memory_nokmem global, however, it is unnecessary
> because there is already a function mem_cgroup_kmem_disabled() which
> exports it.
>
> Just make it static and replace it with mem_cgroup_kmem_disabled()
> in mm/slab_common.c.
>
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>

> ---
> mm/internal.h | 5 -----
> mm/memcontrol.c | 2 +-
> mm/slab_common.c | 2 +-
> 3 files changed, 2 insertions(+), 7 deletions(-)
>
> diff --git a/mm/internal.h b/mm/internal.h
> index 18256e32a14c..ad15251d7a3c 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -137,11 +137,6 @@ extern void putback_lru_page(struct page *page);
> extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
>
> /*
> - * in mm/memcontrol.c:
> - */
> -extern bool cgroup_memory_nokmem;
> -
> -/*
> * in mm/page_alloc.c
> */
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 8f1d9c028897..89fc3ca65b2d 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -84,7 +84,7 @@ EXPORT_PER_CPU_SYMBOL_GPL(int_active_memcg);
> static bool cgroup_memory_nosocket __ro_after_init;
>
> /* Kernel memory accounting disabled? */
> -bool cgroup_memory_nokmem __ro_after_init;
> +static bool cgroup_memory_nokmem __ro_after_init;
>
> /* Whether the swap controller is active */
> #ifdef CONFIG_MEMCG_SWAP
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index e5d080a93009..d05203a11201 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -849,7 +849,7 @@ new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
> if (type == KMALLOC_RECLAIM) {
> flags |= SLAB_RECLAIM_ACCOUNT;
> } else if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_CGROUP)) {
> - if (cgroup_memory_nokmem) {
> + if (mem_cgroup_kmem_disabled()) {
> kmalloc_caches[type][idx] = kmalloc_caches[KMALLOC_NORMAL][idx];
> return;
> }
>