Re: [PATCH] mm: remove offset check on page->compound_head and folio->lru

Andrew Morton
2022-01-08T00:08:30Z

On Fri, 7 Jan 2022 22:11:20 +0000 Matthew Wilcox <willy@infradead.org> wrote:

> 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.

Well I can't figure out which comment you're referring to?

> If you can't be bothered to read, why should I write?

I don't think the punishment comes close to fitting the crime here :(