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Date: Fri, 26 Sep 2025 21:01:02 +0200
Message-Id: <DD2YPPZ08RMC.2FCYC3HPWY3IC@kernel.org>
To: "Vlastimil Babka" <vbabka@suse.cz>
From: "Danilo Krummrich" <dakr@kernel.org>
Subject: Re: [PATCH] rust: slab: add basic slab module
Cc: "Elijah Wright" <git@elijahs.space>, "Miguel Ojeda" <ojeda@kernel.org>,
 "Alex Gaynor" <alex.gaynor@gmail.com>, "Boqun Feng" <boqun.feng@gmail.com>,
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 Hindborg" <a.hindborg@kernel.org>, "Alice Ryhl" <aliceryhl@google.com>,
 "Trevor Gross" <tmgross@umich.edu>, <rust-for-linux@vger.kernel.org>,
 <linux-kernel@vger.kernel.org>, "Lorenzo Stoakes"
 <lorenzo.stoakes@oracle.com>, "Liam R. Howlett" <Liam.Howlett@oracle.com>,
 "Uladzislau Rezki" <urezki@gmail.com>, <linux-mm@kvack.org>
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In-Reply-To: <57b01f59-f4b1-4f5f-bb63-fd8eea19b7ba@suse.cz>

On Fri Sep 26, 2025 at 7:11 PM CEST, Vlastimil Babka wrote:
> The rust wrapper side could do that so we don't have to add that check in
> all kmem_cache_free() calls, maybe?
> Also either way it could perhaps be difficult/expensive (memory barriers
> etc) to properly handle a racing kmem_cache_free() and kmem_cache_destroy=
()
> in a way that ensures the cache is always being destroyed, and not have t=
he
> kmem_cache_destroy() observe the destroy was premature, while the racing
> kmem_cache_free() doesn't yet observe that destroy was attempted, and not
> try to remove it.

Yeah, it's probably not much better than just using a reference count, but =
more
error prone.