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From: Andreas Hindborg <a.hindborg@kernel.org>
To: Danilo Krummrich <dakr@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>, Boqun Feng <boqun.feng@gmail.com>, Gary
 Guo <gary@garyguo.net>, =?utf-8?Q?Bj=C3=B6rn?= Roy Baron
 <bjorn3_gh@protonmail.com>, Benno
 Lossin <lossin@kernel.org>, Alice
 Ryhl <aliceryhl@google.com>, Trevor Gross <tmgross@umich.edu>, Lorenzo
 Stoakes <lorenzo.stoakes@oracle.com>, Vlastimil Babka <vbabka@suse.cz>,
 "Liam R. Howlett" <Liam.Howlett@oracle.com>, Uladzislau Rezki
 <urezki@gmail.com>, rust-for-linux@vger.kernel.org,
 linux-kernel@vger.kernel.org
Subject: Re: [PATCH] rust: alloc: add GFP_NOIO flag
In-Reply-To: <DG0GX23ANI54.2PQM2BL2IKRLL@kernel.org>
References: <20260128-gfp-noio-v1-1-9a808fc49b44@kernel.org>
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 <DG0GX23ANI54.2PQM2BL2IKRLL@kernel.org>
Date: Wed, 28 Jan 2026 21:33:27 +0100
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"Danilo Krummrich" <dakr@kernel.org> writes:

> On Wed Jan 28, 2026 at 7:37 PM CET, Andreas Hindborg wrote:
>> +    /// [`GFP_NOIO`] will use direct reclaim to discard clean pages or slab
>> +    /// pages that do not require the starting of any physical IO.
>> +    pub const GFP_NOIO: Flags = Flags(bindings::GFP_NOIO);
>
> How do you use this? What about abstractions for memalloc_noio_{save,restore}()
> instead?

I use it to allocate memory for backing storage in rust null block. The
allocation is done during processing of disk IO:

                page: Page::alloc_page(GFP_NOIO | __GFP_ZERO)?,

Best regards,
Andreas Hindborg