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Date:   Thu, 9 Nov 2023 14:10:50 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     Jeff Xie <jeff.xie@linux.dev>
Cc:     akpm@linux-foundation.org, iamjoonsoo.kim@lge.com, vbabka@suse.cz,
        cl@linux.com, penberg@kernel.org, rientjes@google.com,
        roman.gushchin@linux.dev, 42.hyeyoo@gmail.com, linux-mm@kvack.org,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        chensong_2000@189.cn, xiehuan09@gmail.com
Subject: Re: [RFC][PATCH 4/4] mm/rmap: implement anonmap allocate post
 callback for page_owner
Message-ID: <ZUzoanvY4eIc1xK0@casper.infradead.org>
References: <20231109032521.392217-1-jeff.xie@linux.dev>
 <20231109032521.392217-5-jeff.xie@linux.dev>
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On Thu, Nov 09, 2023 at 11:25:21AM +0800, Jeff Xie wrote:
> +static int anon_alloc_post_page_owner(struct folio *folio, struct task_struct *tsk,
> +			void *data, char *kbuf, size_t count)
> +{
> +	int ret;
> +	unsigned long address = (unsigned long)data;
> +
> +	ret = scnprintf(kbuf, count, "ANON_PAGE address 0x%lx\n", address);

... completely ignoring that it might have been mremap() since ...

I'm not an expert on anon memory.  I'm sure someone can tell you how to
figure out the current address that a folio is mapped at.