From: Matthew Wilcox <willy@infradead.org>
To: John Hubbard <jhubbard@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>, Jan Kara <jack@suse.cz>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-block@vger.kernel.org
Subject: Re: RFA (Request for Advice): block/bio: get_user_pages() --> pin_user_pages()
Date: Mon, 24 Jan 2022 13:18:19 +0000 [thread overview]
Message-ID: <Ye6nG6xvVG2xTQkZ@casper.infradead.org> (raw)
In-Reply-To: <e83cd4fe-8606-f4de-41ad-33a40f251648@nvidia.com>
On Sun, Jan 23, 2022 at 11:52:07PM -0800, John Hubbard wrote:
> To ground this in reality, one of the partial call stacks is:
>
> do_direct_IO()
> dio_zero_block()
> page = ZERO_PAGE(0); <-- This is a problem
>
> I'm not sure what to use, instead of that zero page! The zero page
> doesn't need to be allocated nor tracked, and so any replacement
> approaches would need either other storage, or some horrid scheme that I
> won't go so far as to write on the screen. :)
I'm not really sure what the problem is.
include/linux/mm.h: is_zero_pfn(page_to_pfn(page));
and release_pages() already contains:
if (is_huge_zero_page(page))
continue;
Why can't the BIO release function contain an is_zero_pfn() check?
next prev parent reply other threads:[~2022-01-24 13:18 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-24 7:52 RFA (Request for Advice): block/bio: get_user_pages() --> pin_user_pages() John Hubbard
2022-01-24 10:05 ` Jan Kara
2022-01-24 10:38 ` Chaitanya Kulkarni
2022-01-24 12:19 ` Jan Kara
2022-01-24 19:34 ` John Hubbard
2022-01-24 21:06 ` Jan Kara
2022-01-24 21:06 ` John Hubbard
2022-01-24 22:17 ` Jan Kara
2022-01-24 13:18 ` Matthew Wilcox [this message]
2022-01-24 19:48 ` John Hubbard
2022-01-26 5:42 ` Chaitanya Kulkarni
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Ye6nG6xvVG2xTQkZ@casper.infradead.org \
--to=willy@infradead.org \
--cc=hch@lst.de \
--cc=jack@suse.cz \
--cc=jhubbard@nvidia.com \
--cc=linux-block@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox