Date:   Fri, 7 Jan 2022 22:11:20 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     Wei Yang <richard.weiyang@gmail.com>
Cc:     peterz@infradead.org, akpm@linux-foundation.org, vbabka@suse.cz,
        will@kernel.org, linyunsheng@huawei.com, aarcange@redhat.com,
        feng.tang@intel.com, ebiederm@xmission.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: remove offset check on page->compound_head and
 folio->lru
Message-ID: <Ydi6iMbSZ/FewYPT@casper.infradead.org>
References: <20220106235254.19190-1-richard.weiyang@gmail.com>
 <Yde6hZ41agqa2zs3@casper.infradead.org>
 <20220107134059.flxr2hcd6ilb6vt7@master>
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On Fri, Jan 07, 2022 at 01:40:59PM +0000, Wei Yang wrote:
> On Fri, Jan 07, 2022 at 03:59:01AM +0000, Matthew Wilcox wrote:
> >On Thu, Jan 06, 2022 at 11:52:54PM +0000, Wei Yang wrote:
> >> FOLIO_MATCH() is used to make sure struct page and folio has identical
> >> layout for the first several words.
> >> 
> >> The comparison of offset between page->compound_head and folio->lru is
> >> more like an internal check in struct page.
> >> 
> >> This patch just removes it.
> >> 
> >> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> >
> >No.
> 
> Hi, Matthew
> 
> Would you mind sharing some insight on this check?

It's right there in the comments.  If you can't be bothered to read,
why should I write?