From: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>
To: Mike Rapoport <rppt@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@kernel.org>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
Barry Song <baohua@kernel.org>, Dev Jain <dev.jain@arm.com>,
Hugh Dickins <hughd@google.com>, Jann Horn <jannh@google.com>,
Jason Gunthorpe <jgg@ziepe.ca>,
John Hubbard <jhubbard@nvidia.com>,
Jonathan Corbet <corbet@lwn.net>,
Lance Yang <lance.yang@linux.dev>,
"Liam R. Howlett" <liam@infradead.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Michal Hocko <mhocko@suse.com>,
Muchun Song <muchun.song@linux.dev>,
Nico Pache <nico.pache@linux.dev>,
Oscar Salvador <osalvador@suse.de>,
Pedro Falcato <pfalcato@suse.de>, Peter Xu <peterx@redhat.com>,
Ryan Roberts <ryan.roberts@arm.com>,
Shakeel Butt <shakeel.butt@linux.dev>,
Shuah Khan <skhan@linuxfoundation.org>,
Steven Rostedt <rostedt@goodmis.org>,
Suren Baghdasaryan <surenb@google.com>,
Usama Arif <usama.arif@linux.dev>,
Vlastimil Babka <vbabka@kernel.org>, Zi Yan <ziy@nvidia.com>,
linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH 6/6] userfaultfd: collapse VM_UFFD_{MISSING,WP,MINOR,RWP} into single VM_UFFD
Date: Thu, 27 Aug 2026 12:18:14 +0100 [thread overview]
Message-ID: <apAcweThjiD-iIBF@gremlin> (raw)
In-Reply-To: <apAB9GSnHNyNoSc1@gremlin>
On Thu, Aug 27, 2026 at 12:16:32PM +0100, Lorenzo Stoakes (ARM) wrote:
> So actually you're increasing by a cacheline and increasing the VMA size by
> 64 bytes, i.e. 1/3, which is unacceptable obviously.
>
> Maybe there's something that can be done with:
>
> /* forced alignments: 1 */
>
> Perhaps? But that looks potentially ugly.
>
I say elsewhere (or think I do) but to highlight - I think probably we could fix
this by putting the flags in the low bits of vm_uffd_state.ctx?
--
Cheers, Lorenzo
next prev parent reply other threads:[~2026-08-27 11:18 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-23 12:17 [PATCH 0/6] userfaultfd: decouple uffd mode from VMA flags Mike Rapoport (Microsoft)
2026-08-23 12:17 ` [PATCH 1/6] mm/gup: move gup_can_follow_protnone() to gup.c Mike Rapoport (Microsoft)
2026-08-23 21:03 ` Barry Song
2026-08-24 14:42 ` David Hildenbrand (Arm)
2026-08-25 10:10 ` Mike Rapoport
2026-08-24 14:59 ` Lorenzo Stoakes (ARM)
2026-08-25 2:03 ` Zi Yan
2026-08-23 12:17 ` [PATCH 2/6] userfaultfd: constify VMA parameter of userfaultfd_*() helpers Mike Rapoport (Microsoft)
2026-08-23 12:27 ` sashiko-bot
2026-08-23 21:03 ` Barry Song
2026-08-24 15:03 ` Lorenzo Stoakes (ARM)
2026-08-25 2:03 ` Zi Yan
2026-08-23 12:17 ` [PATCH 3/6] userfaultfd: use userfaultfd_*() helpers instead of open coded flag tests Mike Rapoport (Microsoft)
2026-08-23 21:14 ` Barry Song
2026-08-24 15:10 ` Lorenzo Stoakes (ARM)
2026-08-25 11:19 ` Mike Rapoport
2026-08-25 11:26 ` Lorenzo Stoakes (ARM)
2026-08-27 7:14 ` Mike Rapoport
2026-08-23 12:17 ` [PATCH 4/6] userfaultfd: rename vm_userfaultfd_ctx to vm_uffd_state Mike Rapoport (Microsoft)
2026-08-24 14:43 ` David Hildenbrand (Arm)
2026-08-24 15:42 ` Lorenzo Stoakes (ARM)
2026-08-23 12:17 ` [PATCH 5/6] userfaultfd: decouple fault reason from VMA flags Mike Rapoport (Microsoft)
2026-08-24 8:12 ` Muchun Song
2026-08-24 14:46 ` David Hildenbrand (Arm)
2026-08-27 7:49 ` Mike Rapoport
2026-08-27 8:10 ` David Hildenbrand (Arm)
2026-08-27 9:09 ` Mike Rapoport
2026-08-27 9:19 ` David Hildenbrand (Arm)
2026-08-27 9:21 ` Lorenzo Stoakes (ARM)
2026-08-24 16:28 ` Lorenzo Stoakes (ARM)
2026-08-25 10:37 ` Mike Rapoport
2026-08-25 11:08 ` David Hildenbrand (Arm)
2026-08-25 11:38 ` Lorenzo Stoakes (ARM)
2026-08-25 13:00 ` Lorenzo Stoakes (ARM)
2026-08-27 7:42 ` Mike Rapoport
2026-08-27 11:29 ` Lorenzo Stoakes (ARM)
2026-08-23 12:17 ` [PATCH 6/6] userfaultfd: collapse VM_UFFD_{MISSING,WP,MINOR,RWP} into single VM_UFFD Mike Rapoport (Microsoft)
2026-08-24 7:11 ` Lance Yang
2026-08-24 8:17 ` Mike Rapoport
2026-08-24 8:27 ` Lance Yang
2026-08-25 12:44 ` Lorenzo Stoakes (ARM)
2026-08-25 12:45 ` Lorenzo Stoakes (ARM)
2026-08-27 9:03 ` Mike Rapoport
2026-08-27 11:16 ` Lorenzo Stoakes (ARM)
2026-08-27 11:18 ` Lorenzo Stoakes (ARM) [this message]
2026-08-27 15:19 ` David Hildenbrand (Arm)
2026-08-29 11:00 ` Mike Rapoport
2026-08-29 18:42 ` Tal Zussman
2026-08-30 5:36 ` Mike Rapoport
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=apAcweThjiD-iIBF@gremlin \
--to=ljs@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=baohua@kernel.org \
--cc=baolin.wang@linux.alibaba.com \
--cc=corbet@lwn.net \
--cc=david@kernel.org \
--cc=dev.jain@arm.com \
--cc=hughd@google.com \
--cc=jannh@google.com \
--cc=jgg@ziepe.ca \
--cc=jhubbard@nvidia.com \
--cc=lance.yang@linux.dev \
--cc=liam@infradead.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=mhiramat@kernel.org \
--cc=mhocko@suse.com \
--cc=muchun.song@linux.dev \
--cc=nico.pache@linux.dev \
--cc=osalvador@suse.de \
--cc=peterx@redhat.com \
--cc=pfalcato@suse.de \
--cc=rostedt@goodmis.org \
--cc=rppt@kernel.org \
--cc=ryan.roberts@arm.com \
--cc=shakeel.butt@linux.dev \
--cc=skhan@linuxfoundation.org \
--cc=surenb@google.com \
--cc=usama.arif@linux.dev \
--cc=vbabka@kernel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.