linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: Huan Yang <link@vivo.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>,
	Michal Hocko <mhocko@kernel.org>,
	Roman Gushchin <roman.gushchin@linux.dev>,
	Shakeel Butt <shakeel.butt@linux.dev>,
	Muchun Song <muchun.song@linux.dev>,
	cgroups@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org, opensource.kernel@vivo.com
Subject: Re: [PATCH 1/2] mm/memcg: use kmem_cache when alloc memcg
Date: Wed, 23 Apr 2025 14:59:12 -0700	[thread overview]
Message-ID: <20250423145912.3e0062864b6969b3623c8ff6@linux-foundation.org> (raw)
In-Reply-To: <20250423084306.65706-2-link@vivo.com>

On Wed, 23 Apr 2025 16:43:04 +0800 Huan Yang <link@vivo.com> wrote:

> @@ -3652,7 +3654,10 @@ static struct mem_cgroup *mem_cgroup_alloc(struct mem_cgroup *parent)
>  	int __maybe_unused i;
>  	long error;
>  
> -	memcg = kzalloc(struct_size(memcg, nodeinfo, nr_node_ids), GFP_KERNEL);
> +	memcg = likely(memcg_cachep) ?
> +			kmem_cache_zalloc(memcg_cachep, GFP_KERNEL) :
> +			kzalloc(struct_size(memcg, nodeinfo, nr_node_ids),
> +				GFP_KERNEL);

Why are we testing for memcg_cachep=NULL?

> @@ -5055,6 +5061,10 @@ static int __init mem_cgroup_init(void)
>  		INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work,
>  			  drain_local_stock);
>  
> +	memcg_size = struct_size_t(struct mem_cgroup, nodeinfo, nr_node_ids);
> +	memcg_cachep = kmem_cache_create("mem_cgroup", memcg_size, 0,
> +					 SLAB_PANIC | SLAB_HWCACHE_ALIGN, NULL);

If it's because this allocation might have failed then let's not
bother.  If an __init-time allocation failed, this kernel is unusable
anyway.




  reply	other threads:[~2025-04-23 21:59 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-23  8:43 [PATCH 0/2] Use kmem_cache for memcg alloc Huan Yang
2025-04-23  8:43 ` [PATCH 1/2] mm/memcg: use kmem_cache when alloc memcg Huan Yang
2025-04-23 21:59   ` Andrew Morton [this message]
2025-04-23 22:13     ` Shakeel Butt
2025-04-24  2:45       ` Huan Yang
2025-04-24  3:31         ` Shakeel Butt
2025-04-24  3:40           ` Huan Yang
2025-04-24  1:46     ` Huan Yang
2025-04-23  8:43 ` [PATCH 2/2] mm/memcg: use kmem_cache when alloc memcg pernode info Huan Yang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20250423145912.3e0062864b6969b3623c8ff6@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=cgroups@vger.kernel.org \
    --cc=hannes@cmpxchg.org \
    --cc=link@vivo.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@kernel.org \
    --cc=muchun.song@linux.dev \
    --cc=opensource.kernel@vivo.com \
    --cc=roman.gushchin@linux.dev \
    --cc=shakeel.butt@linux.dev \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox