From: Matthew Wilcox <willy@infradead.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>, linux-mm@kvack.org
Subject: Re: [PATCH] mm: Introduce page_size()
Date: Thu, 23 May 2019 14:44:02 -0700 [thread overview]
Message-ID: <20190523214402.GA1075@bombadil.infradead.org> (raw)
In-Reply-To: <20190523143315.9191b62231fc57942b490079@linux-foundation.org>
On Thu, May 23, 2019 at 02:33:15PM -0700, Andrew Morton wrote:
> On Wed, 22 May 2019 18:55:11 -0700 Matthew Wilcox <willy@infradead.org> wrote:
>
> > > > + return (unsigned long)PAGE_SIZE << compound_order(page);
> > > > + }
> > >
> > > Also, I suspect the cast here is unneeded. Architectures used to
> > > differe in the type of PAGE_SIZE but please tell me that's been fixed
> > > for a lomng time...
> >
> > It's an unsigned int for most, if not all architectures. For, eg,
> > PowerPC, a PUD page is larger than 4GB. So let's just include the cast
> > and not have to worry about undefined semantics screwing us over.
>
> I think you'll find that PAGE_SIZE is unsigned long on all
> architectures.
arch/openrisc/include/asm/page.h:#define PAGE_SIZE (1 << PAGE_SHIFT)
The others are a miscellany of different defines, but I think you're
right for every other architecture.
next prev parent reply other threads:[~2019-05-23 21:44 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-10 18:12 Matthew Wilcox
2019-05-13 10:56 ` Michal Hocko
2019-05-13 12:43 ` Kirill Tkhai
2019-05-14 11:53 ` William Kucharski
2019-05-22 20:03 ` Andrew Morton
2019-05-23 1:55 ` Matthew Wilcox
2019-05-23 21:33 ` Andrew Morton
2019-05-23 21:44 ` Matthew Wilcox [this message]
2019-05-24 6:34 ` Christoph Hellwig
-- strict thread matches above, loose matches on Subject: below --
2018-12-31 13:42 Matthew Wilcox
2018-12-31 23:02 ` Kirill A. Shutemov
2019-01-01 6:39 ` Matthew Wilcox
2019-01-01 20:11 ` Zi Yan
2019-01-02 0:58 ` Matthew Wilcox
2019-01-02 1:16 ` Zi Yan
2019-01-01 3:27 ` Aneesh Kumar K.V
2019-01-01 3:27 ` Aneesh Kumar K.V
2019-01-01 6:30 ` Matthew Wilcox
2019-01-01 10:11 ` Aneesh Kumar K.V
2019-01-02 3:14 ` Matthew Wilcox
2019-01-02 11:46 ` William Kucharski
2019-01-02 13:09 ` Matthew Wilcox
2019-01-03 10:47 ` William Kucharski
2019-01-01 10:15 ` Aneesh Kumar K.V
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