From: "Vlastimil Babka (SUSE)" <vbabka@kernel.org>
To: "Harry Yoo (Oracle)" <harry@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@gentwo.org>,
David Rientjes <rientjes@google.com>,
Roman Gushchin <roman.gushchin@linux.dev>,
Hao Li <hao.li@linux.dev>, Alexei Starovoitov <ast@kernel.org>,
Uladzislau Rezki <urezki@gmail.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>,
Boqun Feng <boqun@kernel.org>, Zqiang <qiang.zhang@linux.dev>,
Steven Rostedt <rostedt@goodmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
rcu@vger.kernel.org, linux-mm@kvack.org,
Alexander Viro <viro@zeniv.linux.org.uk>,
Christian Brauner <brauner@kernel.org>
Subject: Re: [RFC PATCH v2 0/8] kvfree_rcu() improvements
Date: Wed, 22 Apr 2026 16:30:07 +0200 [thread overview]
Message-ID: <214ca3ac-45b7-4131-86e5-ac134ab0bcbd@kernel.org> (raw)
In-Reply-To: <20260416091022.36823-1-harry@kernel.org>
On 4/16/26 11:10, Harry Yoo (Oracle) wrote:
> # Part 1. Allow an 8-byte field to be used as an alternative to
> struct rcu_head for 2-argument kvfree_rcu()
> (patches 1-2)
>
> Technically, objects that are freed with k[v]free_rcu() need
> only one pointer to link objects, because we already know that
> the callback function is always kvfree(). For this purpose,
> struct rcu_head is unnecessarily large (16 bytes on 64-bit).
>
> Allow a smaller, 8-byte field (of struct rcu_ptr type) to be used
> with k[v]free_rcu(). Let's save one pointer per slab object.
>
> I have to admit that my naming skill isn't great; hopefully
> we'll come up with a better name than `struct rcu_ptr`.
"rcu_ptr" sounds too generic to me. Things like rcu_dereference() talk about
"RCU-protected pointer" and it could be misleading that "rcu_ptr" has
something to do with this. Only if Paul think it's ok :)
But maybe just "kvfree_rcu_head"? As IMHO It's an rcu_head specialized for
kvfree.
next prev parent reply other threads:[~2026-04-22 14:30 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-16 9:10 [RFC PATCH v2 0/8] kvfree_rcu() improvements Harry Yoo (Oracle)
2026-04-16 9:10 ` [PATCH 1/8] mm/slab: introduce k[v]free_rcu() with struct rcu_ptr Harry Yoo (Oracle)
2026-04-22 14:41 ` Vlastimil Babka (SUSE)
2026-04-16 9:10 ` [PATCH 2/8] fs/dcache: use rcu_ptr instead of rcu_head for external names Harry Yoo (Oracle)
2026-04-21 20:21 ` Al Viro
2026-04-22 1:16 ` Harry Yoo (Oracle)
2026-04-16 9:10 ` [PATCH 3/8] mm/slab: move kfree_rcu_cpu[_work] definitions Harry Yoo (Oracle)
2026-04-16 9:10 ` [PATCH 4/8] mm/slab: introduce kfree_rcu_nolock() Harry Yoo (Oracle)
2026-04-21 22:46 ` Alexei Starovoitov
2026-04-21 23:10 ` Paul E. McKenney
2026-04-21 23:14 ` Alexei Starovoitov
2026-04-22 3:02 ` Harry Yoo (Oracle)
2026-04-22 14:42 ` Uladzislau Rezki
2026-04-16 9:10 ` [PATCH 5/8] mm/slab: make kfree_rcu_nolock() work with sheaves Harry Yoo (Oracle)
2026-04-16 9:10 ` [PATCH 6/8] mm/slab: wrap rcu sheaf handling with ifdef Harry Yoo (Oracle)
2026-04-16 9:10 ` [PATCH 7/8] mm/slab: introduce deferred submission of rcu sheaves Harry Yoo (Oracle)
2026-04-21 22:51 ` Alexei Starovoitov
2026-04-22 3:11 ` Harry Yoo (Oracle)
2026-04-16 9:10 ` [PATCH 8/8] lib/tests/slub_kunit: add a test case for kfree_rcu_nolock() Harry Yoo (Oracle)
2026-04-22 14:30 ` Vlastimil Babka (SUSE) [this message]
2026-04-22 22:41 ` [RFC PATCH v2 0/8] kvfree_rcu() improvements Paul E. McKenney
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