From: Will Deacon <will@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>, Minchan Kim <minchan@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Hugh Dickins <hughd@google.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
Vinayak Menon <vinmenon@codeaurora.org>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
"Kirill A. Shutemov" <kirill@shutemov.name>,
Andrew Morton <akpm@linux-foundation.org>,
Android Kernel Team <kernel-team@android.com>,
Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v2 0/3] Create 'old' ptes for faultaround mappings on arm64 with hardware access flag
Date: Tue, 12 Jan 2021 21:47:59 +0000 [thread overview]
Message-ID: <20210112214759.GC10434@willie-the-truck> (raw)
In-Reply-To: <CAHk-=whYs9XsO88iqJzN6NC=D-dp2m0oYXuOoZ=eWnvv=5OA+w@mail.gmail.com>
On Mon, Jan 11, 2021 at 11:25:37AM -0800, Linus Torvalds wrote:
> On Mon, Jan 11, 2021 at 6:24 AM Kirill A. Shutemov <kirill@shutemov.name> wrote:
> >
> > I wonder if it would be acceptable to pass down to faultaround a copy
> > of vmf, so it mess with it without risking to corrupt the original one?
>
> I'd almost prefer to split vmf into two parts: the 'this is the fault
> info' part and the 'this is the fault handling state' part.
>
> So the first one would be filled in by the actual page faulter (or
> GUP) - and then be 'const' during the lookup, while the second one
> would be set up by handle_mm_fault() and would contain that "this is
> the current state of my fault state machine" and contain things like
> that ->pte thing.
>
> And then if somebody actually needs to pass in "modified fault state"
> (ie that whole "I'm doing fault-around, so I'll use multiple
> addresses") they'd never modify the address in the fault info, they'd
> just pass the address as an explicit argument (like most cases already
> do - the "change addr or flags in vmf" is actually already _fairly_
> rare).
Alright then, I'll take another crack at this for v3 and see how far I
get.
Will
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-01-12 21:50 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-08 17:15 [PATCH v2 0/3] Create 'old' ptes for faultaround mappings on arm64 with hardware access flag Will Deacon
2021-01-08 17:15 ` [PATCH v2 1/3] mm: Cleanup faultaround and finish_fault() codepaths Will Deacon
2021-01-11 14:26 ` Kirill A. Shutemov
2021-01-11 14:27 ` Will Deacon
2021-01-08 17:15 ` [PATCH v2 2/3] mm: Allow architectures to request 'old' entries when prefaulting Will Deacon
2021-01-11 14:25 ` Kirill A. Shutemov
2021-01-11 14:37 ` Will Deacon
2021-01-11 14:47 ` Kirill A. Shutemov
2021-01-08 17:15 ` [PATCH v2 3/3] arm64: mm: Implement arch_wants_old_prefaulted_pte() Will Deacon
2021-01-08 19:34 ` [PATCH v2 0/3] Create 'old' ptes for faultaround mappings on arm64 with hardware access flag Linus Torvalds
2021-01-08 19:42 ` Linus Torvalds
2021-01-11 14:01 ` Will Deacon
2021-01-11 13:30 ` Will Deacon
2021-01-11 21:03 ` Hugh Dickins
2021-01-12 21:46 ` Will Deacon
2021-01-11 14:24 ` Kirill A. Shutemov
2021-01-11 19:25 ` Linus Torvalds
2021-01-12 21:47 ` Will Deacon [this message]
2021-01-12 21:55 ` Linus Torvalds
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=20210112214759.GC10434@willie-the-truck \
--to=will@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=catalin.marinas@arm.com \
--cc=hughd@google.com \
--cc=jack@suse.cz \
--cc=kernel-team@android.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=kirill@shutemov.name \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=minchan@kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=vinmenon@codeaurora.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;
as well as URLs for NNTP newsgroup(s).