LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Yang Shi <shy828301@gmail.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>, Zi Yan <ziy@nvidia.com>,
"Kirill A. Shutemov" <kirill@shutemov.name>,
Kent Overstreet <kent.overstreet@gmail.com>,
Linux FS-devel Mailing List <linux-fsdevel@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux MM <linux-mm@kvack.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
"Darrick J. Wong" <djwong@kernel.org>,
Christoph Hellwig <hch@infradead.org>,
David Howells <dhowells@redhat.com>,
Mike Kravetz <mike.kravetz@oracle.com>
Subject: Re: Mapcount of subpages
Date: Thu, 23 Sep 2021 20:26:22 -0700 [thread overview]
Message-ID: <CAHbLzkpTXxzR7=5mYAOFfu0M2jN5cnvbQMHu3bTba8PSdRDSXg@mail.gmail.com> (raw)
In-Reply-To: <YU0qdpbjK5Hdfk2p@casper.infradead.org>
On Thu, Sep 23, 2021 at 6:32 PM Matthew Wilcox <willy@infradead.org> wrote:
>
> On Thu, Sep 23, 2021 at 06:11:19PM -0700, Yang Shi wrote:
> > On Thu, Sep 23, 2021 at 4:49 PM Hugh Dickins <hughd@google.com> wrote:
> > > I believe Yang Shi is right insofar as the decision on whether it's worth
> > > queuing for deferred split is being done based on those subpage _mapcounts.
> > > That is a use I had not considered, and I've given no thought to how
> > > important or not it is.
> >
> > Anyway deferred split is anon THP specific. We don't have to worry
> > about this for file THP. So your suggestion about just counting total
> > mapcount seems feasible to me for file THP at least.
>
> But I think we probably *should* do deferred split for file THP.
> At the moment, when we truncate to the middle of a shmem THP, we try
> a few times to split it and then just give up. We should probably try
> once and then queue it for deferred split.
Yes, probably. Anyway this doesn't need _mapcount of subpages.
next prev parent reply other threads:[~2021-09-24 3:26 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-23 1:21 Struct page proposal Kent Overstreet
2021-09-23 3:23 ` Matthew Wilcox
2021-09-23 5:15 ` Kent Overstreet
2021-09-23 11:40 ` Mapcount of subpages Matthew Wilcox
2021-09-23 12:45 ` Kirill A. Shutemov
2021-09-23 21:10 ` Hugh Dickins
2021-09-23 21:54 ` Yang Shi
2021-09-23 22:23 ` Zi Yan
2021-09-23 23:48 ` Hugh Dickins
2021-09-24 0:25 ` Zi Yan
2021-09-24 0:57 ` Hugh Dickins
2021-09-24 1:11 ` Yang Shi
2021-09-24 1:31 ` Matthew Wilcox
2021-09-24 3:26 ` Yang Shi [this message]
2021-09-24 23:05 ` Kirill A. Shutemov
2021-09-23 18:56 ` Mike Kravetz
2021-09-23 9:03 ` Struct page proposal David Hildenbrand
2021-09-23 15:22 ` Kent Overstreet
2021-09-23 15:34 ` David Hildenbrand
2021-09-27 17:48 ` Vlastimil Babka
2021-09-27 17:53 ` Kent Overstreet
2021-09-27 18:34 ` Linus Torvalds
2021-09-27 20:45 ` David Hildenbrand
2021-09-27 18:05 ` Matthew Wilcox
2021-09-27 18:09 ` Kent Overstreet
2021-09-27 18:12 ` Matthew Wilcox
2021-09-27 18:16 ` David Hildenbrand
2021-09-27 18:53 ` Vlastimil Babka
2021-09-27 19:04 ` Linus Torvalds
2021-09-27 18:16 ` Kent Overstreet
2021-09-28 3:19 ` Matthew Wilcox
2021-09-27 19:07 ` Vlastimil Babka
2021-09-27 20:14 ` Kent Overstreet
2021-09-28 11:21 ` David Laight
2021-09-27 18:33 ` Kirill A. Shutemov
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='CAHbLzkpTXxzR7=5mYAOFfu0M2jN5cnvbQMHu3bTba8PSdRDSXg@mail.gmail.com' \
--to=shy828301@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=dhowells@redhat.com \
--cc=djwong@kernel.org \
--cc=hannes@cmpxchg.org \
--cc=hch@infradead.org \
--cc=hughd@google.com \
--cc=kent.overstreet@gmail.com \
--cc=kirill@shutemov.name \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mike.kravetz@oracle.com \
--cc=torvalds@linux-foundation.org \
--cc=willy@infradead.org \
--cc=ziy@nvidia.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 NNTP newsgroup(s).