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Date:   Fri, 24 Mar 2023 16:17:17 +0100
From:   Michal =?utf-8?Q?Koutn=C3=BD?= <mkoutny@suse.com>
To:     Zi Yan <ziy@nvidia.com>
Cc:     "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        Yang Shi <shy828301@gmail.com>, Yu Zhao <yuzhao@google.com>,
        linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org
Subject: Re: [PATCH 2/5] mm: page_owner: add support for splitting to any
 order in split page_owner.
Message-ID: <20230324151717.hawuy5gs6cnxql55@blackpad>
References: <20230321004829.2012847-1-zi.yan@sent.com>
 <20230321004829.2012847-3-zi.yan@sent.com>
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Hello.

On Mon, Mar 20, 2023 at 08:48:26PM -0400, Zi Yan <zi.yan@sent.com> wrote:
> @@ -5746,8 +5746,8 @@ static void *make_alloc_exact(unsigned long addr, u=
nsigned int order,
>  		struct page *page =3D virt_to_page((void *)addr);
>  		struct page *last =3D page + nr;
> =20
> -		split_page_owner(page, 1 << order);
> -		split_page_memcg(page, 1 << order);
> +		split_page_owner(page, 1 << order, 1);
> +		split_page_memcg(page, 1 << order, 1);

I think here should be

> +		split_page_owner(page, order, 0);
> +		split_page_memcg(page, 1 << order, 1);

because I was wondering why split_page_memcg() doesn't use orders too?
(E.g. it wouldn't work well if nr % new_new !=3D 0).

Thanks,
Michal

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