From: Wedson Almeida Filho <wedsonaf@gmail.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: rust-for-linux@vger.kernel.org, "Miguel Ojeda" <ojeda@kernel.org>,
"Alex Gaynor" <alex.gaynor@gmail.com>,
"Boqun Feng" <boqun.feng@gmail.com>,
"Gary Guo" <gary@garyguo.net>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
linux-kernel@vger.kernel.org,
"Wedson Almeida Filho" <walmeida@microsoft.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Ingo Molnar" <mingo@redhat.com>, "Will Deacon" <will@kernel.org>,
"Waiman Long" <longman@redhat.com>
Subject: Re: [PATCH v2 01/13] rust: sync: introduce `LockClassKey`
Date: Wed, 5 Apr 2023 17:05:10 -0300 [thread overview]
Message-ID: <ZC3UdivcMmcZ5MTJ@wedsonaf-dev> (raw)
In-Reply-To: <2023040519-crank-quarry-ef26@gregkh>
On Wed, Apr 05, 2023 at 08:00:15PM +0200, Greg KH wrote:
> On Wed, Apr 05, 2023 at 02:50:59PM -0300, Wedson Almeida Filho wrote:
> > From: Wedson Almeida Filho <walmeida@microsoft.com>
> >
> > +/// Represents a lockdep class. It's a wrapper around C's `lock_class_key`.
> > +#[repr(transparent)]
> > +pub struct LockClassKey(Opaque<bindings::lock_class_key>);
>
> Will this disappear into "nothing" if lockdep is disabled in the build?
>
> If not, it should, if so, I couldn't see where that option was, sorry
> for the noise.
Yeah, the C definition of lock_class_key is an empty struct, which is a
zero-sized type. So instances of this type will occupy 0 bytes.
We'll still have the cost of passing pointers from Rust to C of instances of
this type, which we could add an alternate version (dependent on lockdep being
enabled or not) in Rust to avoid, but since it will be optimised away when LTO
is enabled and doesn't add up to much when LTO is disabled, we chose the simpler
option of having a single implementation.
next prev parent reply other threads:[~2023-04-05 20:05 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-05 17:50 [PATCH v2 01/13] rust: sync: introduce `LockClassKey` Wedson Almeida Filho
2023-04-05 17:51 ` [PATCH v2 02/13] rust: sync: introduce `Lock` and `Guard` Wedson Almeida Filho
2023-04-05 17:51 ` [PATCH v2 03/13] rust: lock: introduce `Mutex` Wedson Almeida Filho
2023-04-05 18:03 ` Greg KH
2023-04-05 18:04 ` Greg KH
2023-04-05 19:18 ` Peter Zijlstra
2023-04-05 20:21 ` Wedson Almeida Filho
2023-04-05 20:29 ` Peter Zijlstra
2023-04-05 20:40 ` Wedson Almeida Filho
2023-04-05 20:49 ` Peter Zijlstra
2023-04-06 8:38 ` David Laight
2023-04-06 11:21 ` Marco Elver
2023-04-06 16:25 ` Miguel Ojeda
2023-04-06 16:45 ` Miguel Ojeda
2023-04-05 17:51 ` [PATCH v2 04/13] locking/spinlock: introduce spin_lock_init_with_key Wedson Almeida Filho
2023-04-05 17:51 ` [PATCH v2 05/13] rust: lock: introduce `SpinLock` Wedson Almeida Filho
2023-04-05 17:51 ` [PATCH v2 06/13] rust: lock: add support for `Lock::lock_irqsave` Wedson Almeida Filho
2023-04-05 17:51 ` [PATCH v2 07/13] rust: lock: implement `IrqSaveBackend` for `SpinLock` Wedson Almeida Filho
2023-04-05 17:51 ` [PATCH v2 08/13] rust: introduce `ARef` Wedson Almeida Filho
2023-04-07 21:59 ` Benno Lossin
2023-04-08 4:28 ` Wedson Almeida Filho
2023-04-05 17:51 ` [PATCH v2 09/13] rust: add basic `Task` Wedson Almeida Filho
2023-04-05 17:51 ` [PATCH v2 10/13] rust: introduce `current` Wedson Almeida Filho
2023-04-07 22:36 ` Benno Lossin
2023-04-08 3:54 ` Wedson Almeida Filho
2023-04-05 17:51 ` [PATCH v2 11/13] rust: lock: add `Guard::do_unlocked` Wedson Almeida Filho
2023-04-05 17:51 ` [PATCH v2 12/13] rust: sync: introduce `CondVar` Wedson Almeida Filho
2023-04-05 17:51 ` [PATCH v2 13/13] rust: sync: introduce `LockedBy` Wedson Almeida Filho
2023-04-07 21:00 ` Benno Lossin
2023-04-08 4:11 ` Wedson Almeida Filho
2023-04-08 7:52 ` Benno Lossin
2023-04-05 18:00 ` [PATCH v2 01/13] rust: sync: introduce `LockClassKey` Greg KH
2023-04-05 20:05 ` Wedson Almeida Filho [this message]
2023-04-05 20:21 ` Gary Guo
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=ZC3UdivcMmcZ5MTJ@wedsonaf-dev \
--to=wedsonaf@gmail.com \
--cc=alex.gaynor@gmail.com \
--cc=bjorn3_gh@protonmail.com \
--cc=boqun.feng@gmail.com \
--cc=gary@garyguo.net \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=longman@redhat.com \
--cc=mingo@redhat.com \
--cc=ojeda@kernel.org \
--cc=peterz@infradead.org \
--cc=rust-for-linux@vger.kernel.org \
--cc=walmeida@microsoft.com \
--cc=will@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;
as well as URLs for NNTP newsgroup(s).