From: Philipp Stanner <phasta@mailbox.org>
To: "Andreas Hindborg" <a.hindborg@kernel.org>,
"Philipp Stanner" <phasta@kernel.org>,
"Miguel Ojeda" <ojeda@kernel.org>,
"Boqun Feng" <boqun@kernel.org>, "Gary Guo" <gary@garyguo.net>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
"Benno Lossin" <lossin@kernel.org>,
"Alice Ryhl" <aliceryhl@google.com>,
"Trevor Gross" <tmgross@umich.edu>,
"Danilo Krummrich" <dakr@kernel.org>,
"Daniel Almeida" <daniel.almeida@collabora.com>,
"Tamir Duberstein" <tamird@kernel.org>,
"Alexandre Courbot" <acourbot@nvidia.com>,
"Onur Özkan" <work@onurozkan.dev>,
"Sumit Semwal" <sumit.semwal@linaro.org>,
"Christian König" <christian.koenig@amd.com>,
"Lyude Paul" <lyude@redhat.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
"Frederic Weisbecker" <frederic@kernel.org>,
"Neeraj Upadhyay" <neeraj.upadhyay@kernel.org>,
"Joel Fernandes" <joelagnelf@nvidia.com>,
"Josh Triplett" <josh@joshtriplett.org>,
"Uladzislau Rezki" <urezki@gmail.com>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Mathieu Desnoyers" <mathieu.desnoyers@efficios.com>,
"Lai Jiangshan" <jiangshanlai@gmail.com>,
Zqiang <qiang.zhang@linux.dev>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Yury Norov (NVIDIA)" <yury.norov@gmail.com>,
"Asahi Lina" <lina+kernel@asahilina.net>,
"Lorenzo Stoakes" <ljs@kernel.org>,
"FUJITA Tomonori" <fujita.tomonori@gmail.com>,
"Eliot Courtney" <ecourtney@nvidia.com>,
"Mirko Adzic" <adzicmirko97@gmail.com>,
"Daniel del Castillo" <delcastillodelarosadaniel@gmail.com>,
"Alistair Francis" <alistair.francis@wdc.com>
Cc: linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org,
linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org,
linaro-mm-sig@lists.linaro.org, rcu@vger.kernel.org
Subject: Re: [PATCH v6 4/6] rust: xarray: Add support for index reservations
Date: Wed, 05 Aug 2026 10:53:19 +0200 [thread overview]
Message-ID: <fb668789376a8a2289cbfe4ef64d9e1bdeb5ff39.camel@mailbox.org> (raw)
In-Reply-To: <87se4t7xy7.fsf@t14s.mail-host-address-is-not-set>
On Wed, 2026-08-05 at 10:50 +0200, Andreas Hindborg wrote:
> "Philipp Stanner" <phasta@kernel.org> writes:
>
> > One often cannot allocate in the kernel with the desired flags, most
> > notably in atomic context. Pre-allocating the memory is the preferred
> > solution in such situations.
> >
> > Add support for xa_reserve() in the Rust abstractions of xarray. Create
> > a Reservation object similar to a lock-guard, that can be dropped once
> > the reservation is no longer needed or once the index was stored to.
> >
> > Signed-off-by: Philipp Stanner <phasta@kernel.org>
> > ---
> > Please regard this more as an RFC.
> >
> > I need pre-allocating in XArray for DmaFence. How exactly we achieve
> > this is open for discussion.
>
> Do you need to actually reserve a key, or do you just need atomic
> allocation?
I would just have needed a position to store to, but the fence sequence
number would be the only reasonable index, so you'd also reserve a key.
Anyways, please forget about this for now, we abstained from using the
XArray in the current revision (v8) of this patch series.
Thx
P.
next prev parent reply other threads:[~2026-08-05 8:53 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-22 14:49 [PATCH v6 0/6] rust / dma_buf: Add abstractions for dma_fence Philipp Stanner
2026-07-22 14:49 ` [PATCH v6 1/6] rust: types: implement ForeignOwnable for ARef<T> Philipp Stanner
2026-07-22 14:49 ` [PATCH v6 2/6] rust: error: Add ECANCELED error code Philipp Stanner
2026-07-22 17:44 ` Alistair Francis
2026-07-22 18:38 ` Timur Tabi
2026-07-23 11:56 ` Philipp Stanner
2026-07-23 12:06 ` Miguel Ojeda
2026-07-22 14:49 ` [PATCH v6 3/6] rust: sync: Add abstraction for rcu_barrier() Philipp Stanner
2026-07-22 14:49 ` [PATCH v6 4/6] rust: xarray: Add support for index reservations Philipp Stanner
2026-08-05 8:50 ` Andreas Hindborg
2026-08-05 8:53 ` Philipp Stanner [this message]
2026-07-22 14:49 ` [PATCH v6 5/6] rust: Add dma_fence abstractions Philipp Stanner
2026-07-22 14:49 ` [PATCH v6 6/6] MAINTAINERS: Add entry for Rust dma-buf Philipp Stanner
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