From: Matthew Wilcox <willy@infradead.org>
To: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>,
linux-mm@kvack.org,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Subject: Re: [PATCH] mm: Improve dump_page() for compound pages
Date: Mon, 10 Feb 2020 14:02:15 -0800 [thread overview]
Message-ID: <20200210220215.GO8731@bombadil.infradead.org> (raw)
In-Reply-To: <1d2ceaff-2cd5-8a03-97d0-556c1b48a69f@nvidia.com>
On Mon, Feb 10, 2020 at 02:00:39PM -0800, John Hubbard wrote:
> On 2/10/20 1:54 PM, Kirill A. Shutemov wrote:
> > On Mon, Feb 10, 2020 at 01:33:22PM -0800, John Hubbard wrote:
> >>> PageSlab() can be called for the head page.
> >>
> >>
> >> It's not clear to me whether it's safer to use the...user-provided page, or the
> >> head page, for checking PageSlab()--it's probably set on both head and non-head
> >> pages, right?
> >
> > PageSlab() will call compound_head() inside.
> >
> >> I guess you're saying it should be like this:
> >>
> >> mapcount = PageSlab(head) ? 0 : page_mapcount(page);
> >>
> >> ...yes?
> >
> > Yes.
> >
>
> OK very good, thanks for walking me through it. :)
>
> Matthew, if you like I'll just fix it up like that for my v6 posting of the
> patchset, since it's such a small change.
Yes, please just fix it up.
prev parent reply other threads:[~2020-02-10 22:02 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-08 4:44 Matthew Wilcox
2020-02-08 4:48 ` Matthew Wilcox
2020-02-09 1:09 ` John Hubbard
2020-02-09 1:12 ` Matthew Wilcox
2020-02-09 1:18 ` John Hubbard
2020-02-10 12:42 ` Kirill A. Shutemov
2020-02-10 19:50 ` John Hubbard
2020-02-10 21:21 ` Kirill A. Shutemov
2020-02-10 21:33 ` John Hubbard
2020-02-10 21:54 ` Kirill A. Shutemov
2020-02-10 22:00 ` John Hubbard
2020-02-10 22:02 ` Matthew Wilcox [this message]
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