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Date: Tue, 2 Jan 2024 17:53:36 -0800
From: Roman Gushchin <roman.gushchin@linux.dev>
To: Haifeng Xu <haifeng.xu@shopee.com>
Cc: akpm@linux-foundation.org, hannes@cmpxchg.org, mhocko@kernel.org,
	shakeelb@google.com, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] mm: list_lru: disable memcg_aware when cgroup.memory
 is set to "nokmem"
Message-ID: <ZZS-IFA6TScotocU@P9FQF9L96D>
References: <20231228062715.338672-1-haifeng.xu@shopee.com>
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In-Reply-To: <20231228062715.338672-1-haifeng.xu@shopee.com>

On Thu, Dec 28, 2023 at 06:27:14AM +0000, Haifeng Xu wrote:
> Actually, when using a boot time kernel option "cgroup.memory=nokmem",
> all lru items are inserted to list_lru_node. But for those users who
> invoke list_lru_init_memcg() to initialize list_lru, list_lru_memcg_aware()
> returns true. And this brings unneeded operations related to memcg.
> 
> To make things more convenient, let's disable memcg_aware when
> cgroup.memory is set to "nokmem".

I guess it's not only more convenient, but also should save a bit of memory.
But _probably_ not enough to justify messing up with stable backports.
Do you have any data on memory savings?

> 
> Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>

Acked-by: Roman Gushchin <roman.gushchin@linux.dev>

Thanks!