From: "Linus Lüssing" <linus.luessing@c0d3.blue>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: b.a.t.m.a.n@lists.open-mesh.org,
Dmitry Antipov <dmantipov@yandex.ru>,
netdev@vger.kernel.org, rcu@vger.kernel.org
Subject: Re: [PATCH] Revert "batman-adv: prefer kfree_rcu() over call_rcu() with free-only callbacks"
Date: Wed, 12 Jun 2024 18:31:57 +0200 [thread overview]
Message-ID: <ZmnNfU44NekafjA_@sellars> (raw)
In-Reply-To: <020489fa-26a3-422c-8924-7dc71f23422c@paulmck-laptop>
On Wed, Jun 12, 2024 at 09:06:25AM -0700, Paul E. McKenney wrote:
> We are looking into nice ways of solving this, but in the meantime,
> yes, if you are RCU-freeing slab objects into a slab that is destroyed
> at module-unload time, you currently need to stick with call_rcu()
> and rcu_barrier().
>
> We do have some potential solutions to allow use of kfree_rcu() with
> this sort of slab, but they are still strictly potential.
>
> Apologies for my having failed to foresee this particular trap!
>
> Thanx, Paul
No worries, thanks for the help and clarification! This at least
restored my sanity, was starting to doubt my understanding of RCU
and the batman-adv code the longer I tried to find the issue in
batman-adv :D.
next prev parent reply other threads:[~2024-06-12 16:32 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-12 13:33 [PATCH] Revert "batman-adv: prefer kfree_rcu() over call_rcu() with free-only callbacks" Linus Lüssing
2024-06-12 14:06 ` Paul E. McKenney
2024-06-12 14:39 ` Linus Lüssing
2024-06-12 14:54 ` Linus Lüssing
2024-06-12 16:06 ` Paul E. McKenney
2024-06-12 16:31 ` Linus Lüssing [this message]
2024-06-12 18:22 ` Sven Eckelmann
2024-06-12 15:01 ` Paul E. McKenney
2024-06-12 16:25 ` Uladzislau Rezki
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