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Date: Thu, 11 Jan 2024 08:43:38 -0500
From: Johannes Weiner <hannes@cmpxchg.org>
To: Zhiguo Jiang <justinjiang@vivo.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	David Hildenbrand <david@redhat.com>,
	Matthew Wilcox <willy@infradead.org>, Chris Li <chrisl@kernel.org>,
	Michal Hocko <mhocko@suse.com>,
	Kefeng Wang <wangkefeng.wang@huawei.com>,
	Dan Schatzberg <schatzberg.dan@gmail.com>,
	Yosry Ahmed <yosryahmed@google.com>, Yue Zhao <findns94@gmail.com>,
	Hugh Dickins <hughd@google.com>, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, opensource.kernel@vivo.com
Subject: Re: [PATCH v1 2/2] mm:vmscan: fix shrink sc parameters issue
Message-ID: <20240111134338.GB390292@cmpxchg.org>
References: <20240111122451.682-1-justinjiang@vivo.com>
 <20240111122451.682-3-justinjiang@vivo.com>
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In-Reply-To: <20240111122451.682-3-justinjiang@vivo.com>

On Thu, Jan 11, 2024 at 08:24:51PM +0800, Zhiguo Jiang wrote:
> The values of struct scan_control's members obtained by
> prepare_scan_control() are always from root_mem_cgroup, rather than
> the memcg where the shrinked folio is actually located, such as
> sc->anon_cost, sc->file_cost, sc->may_deactivate and so on. This is
> an inaccurate sc values for the actual situation of the current
> shrinking memcg. so we need fix the values of struct scan_control's
> members are corresponding to the current shrinking memcg.

You don't seem to understand how cgroup reclaim works.

Nacked-by: Johannes Weiner <hannes@cmpxchg.org>