From: Barry Song <21cnbao@gmail.com>
To: corbet@lwn.net, linux-mm@kvack.org, akpm@linux-foundation.org,
damon@lists.linux.dev, linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, Barry Song <v-songbaohua@oppo.com>,
SeongJae Park <sj@kernel.org>, Minchan Kim <minchan@kernel.org>,
Michal Hocko <mhocko@suse.com>,
Johannes Weiner <hannes@cmpxchg.org>
Subject: [PATCH] Docs/mm/damon/design: describe the differences for pageout's virtual address and physcial address
Date: Sun, 25 Feb 2024 10:50:23 +1300 [thread overview]
Message-ID: <20240224215023.5271-1-21cnbao@gmail.com> (raw)
From: Barry Song <v-songbaohua@oppo.com>
The doc needs update. As only in the case of virtual address, we are
calling madvise() with MADV_PAGEOUT; but in the case of physical
address, we are actually calling reclaim_pages() directly. And
madvise() with MADV_PAGEOUT is much more aggresive on reclamation
compared to reclaim_pages() on paddr.
Cc: SeongJae Park <sj@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
---
Documentation/mm/damon/design.rst | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst
index 8c89d26f0baa..6c50743552f5 100644
--- a/Documentation/mm/damon/design.rst
+++ b/Documentation/mm/damon/design.rst
@@ -315,7 +315,13 @@ that supports each action are as below.
Supported by ``vaddr`` and ``fvaddr`` operations set.
- ``cold``: Call ``madvise()`` for the region with ``MADV_COLD``.
Supported by ``vaddr`` and ``fvaddr`` operations set.
- - ``pageout``: Call ``madvise()`` for the region with ``MADV_PAGEOUT``.
+ - ``pageout``: Call ``madvise()`` for the region with ``MADV_PAGEOUT`` if
+ the region is using virtual address; otherwise, call ``reclaim_pages()``
+ for the region if physical address is used.
+ ``madvise()`` with ``MADV_PAGEOUT`` is aggressively reclaiming memory
+ when pages are not shared by multiple processes. Differently, paddr's
+ pageout will do the best-effort reclamation by scanning PTEs to figure
+ out if pages are young, if not, pages are reclaimed.
Supported by ``vaddr``, ``fvaddr`` and ``paddr`` operations set.
- ``hugepage``: Call ``madvise()`` for the region with ``MADV_HUGEPAGE``.
Supported by ``vaddr`` and ``fvaddr`` operations set.
--
2.34.1
next reply other threads:[~2024-02-24 21:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-24 21:50 Barry Song [this message]
2024-02-24 22:08 ` [PATCH] Docs/mm/damon/design: describe the differences for pageout's virtual address and physcial address SeongJae Park
2024-02-24 22:33 ` Barry Song
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=20240224215023.5271-1-21cnbao@gmail.com \
--to=21cnbao@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=corbet@lwn.net \
--cc=damon@lists.linux.dev \
--cc=hannes@cmpxchg.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=minchan@kernel.org \
--cc=sj@kernel.org \
--cc=v-songbaohua@oppo.com \
/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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).