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Date:   Wed, 10 Nov 2021 01:56:25 +0000
From:   Chris Down <chris@chrisdown.name>
To:     Muchun Song <songmuchun@bytedance.com>
Cc:     akpm@linux-foundation.org, hannes@cmpxchg.org, mhocko@kernel.org,
        vdavydov.dev@gmail.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: memcontrol: make cgroup_memory_nokmem static
Message-ID: <YYsmyXtOHs33E1DV@chrisdown.name>
References: <20211109065418.21693-1-songmuchun@bytedance.com>
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In-Reply-To: <20211109065418.21693-1-songmuchun@bytedance.com>
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Muchun Song writes:
>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@bytedance.com>

Seems reasonable, thanks.

Acked-by: Chris Down <chris@chrisdown.name>

>---
> 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;
> 		}
>-- 
>2.11.0
>
>