From: Christoph Hellwig <hch@infradead.org>
To: Matthew Wilcox <willy@infradead.org>
Cc: David Frank <david@davidfrank.ch>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: Efficient mapping of sparse file holes to zero-pages
Date: Mon, 24 Feb 2025 08:17:18 -0800 [thread overview]
Message-ID: <Z7ybjloC5fobHbTE@infradead.org> (raw)
In-Reply-To: <Z7p-SLdiyQCknetc@casper.infradead.org>
On Sun, Feb 23, 2025 at 01:47:52AM +0000, Matthew Wilcox wrote:
> - Choose a data structure in the VFS to store this range information
> (a tree of some kind)
> - Design a protocol such that the VFS can query this information about
> a range of a particular file, and the filesystem can invalidate the
> VFS's knowledge
That information is always going to be incoherent in some way. Reads
are already done without i_rwsem for most file systems and there is
further work on reducing locking. So anything needs to come from inside
the file system itself. That probably means you can't reduce the folio
allocation overhead, but at least you don't have to persistently use the
memory.
prev parent reply other threads:[~2025-02-24 16:17 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-20 12:48 David Frank
2025-02-20 13:47 ` Matthew Wilcox
2025-02-20 20:46 ` David Frank
2025-02-23 1:47 ` Matthew Wilcox
2025-02-24 16:17 ` Christoph Hellwig [this message]
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=Z7ybjloC5fobHbTE@infradead.org \
--to=hch@infradead.org \
--cc=david@davidfrank.ch \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=willy@infradead.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