From: David Laight <david.laight.linux@gmail.com>
To: Dave Hansen <dave.hansen@intel.com>
Cc: "David Hildenbrand (Arm)" <david@kernel.org>,
Kiryl Shutsemau <kas@kernel.org>,
Kalesh Singh <kaleshsingh@google.com>,
lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org,
x86@kernel.org, linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
Lorenzo Stoakes <lorenzo.stoakes@oracle.com>,
"Liam R. Howlett" <Liam.Howlett@oracle.com>,
Mike Rapoport <rppt@kernel.org>,
Matthew Wilcox <willy@infradead.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Usama Arif <usama.arif@linux.dev>
Subject: Re: [LSF/MM/BPF TOPIC] 64k (or 16k) base page size on x86
Date: Mon, 23 Feb 2026 16:34:23 +0000 [thread overview]
Message-ID: <20260223163423.61a19e5c@pumpkin> (raw)
In-Reply-To: <7b414e68-4d0b-4d2b-a664-bbbdf314c0d3@intel.com>
On Mon, 23 Feb 2026 07:14:39 -0800
Dave Hansen <dave.hansen@intel.com> wrote:
> On 2/23/26 03:27, David Hildenbrand (Arm) wrote:
> ...
> >> BTW, x86-64 SysV ABI allows for 64k page size:
> >>
> >> Systems are permitted to use any power-of-two page size between
> >> 4KB and 64KB, inclusive.
> >>
> >> But it doesn't work in practice.
> >
> > Even in well controlled environments you would run in a hyperscaler?
>
> I think what Kirill is trying to say is that "it breaks userspace". ;)
With a 4k physical page what stops you dynamically splitting the 64k a
'struct page' references into 16 4k pages (using an extra dynamically
allocated structure)?
I'm not thinking it would happen that often, but it would solve the
problem of 4k aligned .data and (probably) mmap() of small files.
If the cpu supports TLB coalescing there could easily be a net gain
using 64k pages for most of a program binary.
David
next prev parent reply other threads:[~2026-02-23 16:34 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-19 15:08 Kiryl Shutsemau
2026-02-19 15:17 ` Peter Zijlstra
2026-02-19 15:20 ` Peter Zijlstra
2026-02-19 15:27 ` Kiryl Shutsemau
2026-02-19 15:33 ` Pedro Falcato
2026-02-19 15:50 ` Kiryl Shutsemau
2026-02-19 15:53 ` David Hildenbrand (Arm)
2026-02-19 19:31 ` Pedro Falcato
2026-02-19 15:39 ` David Hildenbrand (Arm)
2026-02-19 15:54 ` Kiryl Shutsemau
2026-02-19 16:09 ` David Hildenbrand (Arm)
2026-02-20 2:55 ` Zi Yan
2026-02-19 17:09 ` Kiryl Shutsemau
2026-02-20 10:24 ` David Hildenbrand (Arm)
2026-02-20 12:07 ` Kiryl Shutsemau
2026-02-20 16:30 ` David Hildenbrand (Arm)
2026-02-20 19:33 ` Kalesh Singh
2026-02-23 11:04 ` David Hildenbrand (Arm)
2026-02-23 11:13 ` Kiryl Shutsemau
2026-02-23 11:27 ` David Hildenbrand (Arm)
2026-02-23 12:16 ` Kiryl Shutsemau
2026-02-23 15:14 ` Dave Hansen
2026-02-23 15:31 ` David Hildenbrand (Arm)
2026-02-23 15:45 ` Kiryl Shutsemau
2026-02-23 15:49 ` David Hildenbrand (Arm)
2026-02-23 16:22 ` Lorenzo Stoakes
2026-02-23 16:34 ` David Laight [this message]
2026-02-19 23:24 ` Kalesh Singh
2026-02-20 12:10 ` Kiryl Shutsemau
2026-02-20 19:21 ` Kalesh Singh
2026-02-19 17:08 ` Dave Hansen
2026-02-19 22:05 ` Kiryl Shutsemau
2026-02-20 3:28 ` Liam R. Howlett
2026-02-20 12:33 ` Kiryl Shutsemau
2026-02-20 15:17 ` Liam R. Howlett
2026-02-20 15:50 ` Kiryl Shutsemau
2026-02-19 17:30 ` Dave Hansen
2026-02-19 22:14 ` Kiryl Shutsemau
2026-02-19 22:21 ` Dave Hansen
2026-02-19 17:47 ` Matthew Wilcox
2026-02-19 22:26 ` Kiryl Shutsemau
2026-02-20 9:04 ` David Laight
2026-02-20 12:12 ` Kiryl Shutsemau
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=20260223163423.61a19e5c@pumpkin \
--to=david.laight.linux@gmail.com \
--cc=Liam.Howlett@oracle.com \
--cc=akpm@linux-foundation.org \
--cc=bp@alien8.de \
--cc=dave.hansen@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=david@kernel.org \
--cc=hannes@cmpxchg.org \
--cc=kaleshsingh@google.com \
--cc=kas@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=lorenzo.stoakes@oracle.com \
--cc=lsf-pc@lists.linux-foundation.org \
--cc=mingo@redhat.com \
--cc=rppt@kernel.org \
--cc=tglx@linutronix.de \
--cc=usama.arif@linux.dev \
--cc=willy@infradead.org \
--cc=x86@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