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Date: Wed, 20 Mar 2024 15:26:10 +0000
From: Matthew Wilcox <willy@infradead.org>
To: alexs@kernel.org
Cc: Izik Eidus <izik.eidus@ravellosystems.com>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Hugh Dickins <hughd@google.com>, Chris Wright <chrisw@sous-sol.org>,
	kasong@tencent.com, Andrew Morton <akpm@linux-foundation.org>,
	"open list:MEMORY MANAGEMENT" <linux-mm@kvack.org>,
	open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 09/11] mm/ksm: Convert stable_tree_search to use folio
Message-ID: <ZfsAEl5nipppfeLx@casper.infradead.org>
References: <20240320074049.4130552-1-alexs@kernel.org>
 <20240320074049.4130552-10-alexs@kernel.org>
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On Wed, Mar 20, 2024 at 03:40:45PM +0800, alexs@kernel.org wrote:
> @@ -1820,28 +1820,30 @@ static struct page *stable_tree_search(struct page *page)
>  	struct rb_node *parent;
>  	struct ksm_stable_node *stable_node, *stable_node_dup, *stable_node_any;
>  	struct ksm_stable_node *page_node;
> +	struct folio *folio;
>  
> -	page_node = page_stable_node(page);
> +	folio = (struct folio *)page;

These casts make me nervous.  Remember that we're heading towards a
future where struct page and struct folio don't point to the same
memory, and part of that will be finding all these casts and removing
them.  Please, unless there's a good reason, just use page_folio().