From: "Paul E. McKenney" <paulmck@linux.ibm.com>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Joel Fernandes, Google" <joel@joelfernandes.org>,
rcu <rcu@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
dipankar <dipankar@in.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Josh Triplett <josh@joshtriplett.org>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
rostedt <rostedt@goodmis.org>,
David Howells <dhowells@redhat.com>,
Eric Dumazet <edumazet@google.com>, fweisbec <fweisbec@gmail.com>,
Oleg Nesterov <oleg@redhat.com>,
linux-nvdimm <linux-nvdimm@lists.01.org>,
dri-devel <dri-devel@lists.freedesktop.org>,
amd-gfx <amd-gfx@lists.freedesktop.org>
Subject: Re: [PATCH RFC tip/core/rcu 0/4] Forbid static SRCU use in modules
Date: Tue, 9 Apr 2019 12:14:06 -0700 [thread overview]
Message-ID: <20190409191406.GJ14111@linux.ibm.com> (raw)
In-Reply-To: <1445093299.2510.1554833051142.JavaMail.zimbra@efficios.com>
On Tue, Apr 09, 2019 at 02:04:11PM -0400, Mathieu Desnoyers wrote:
> ----- On Apr 9, 2019, at 1:55 PM, paulmck paulmck@linux.ibm.com wrote:
> [...]
> > The current state is not horrible, so my thought would be to give it
> > some time to see if better thoughts arise.
> >
> > Either way, cleanup_srcu_struct() keeps its current checks for callbacks
> > still being in flight, which is why I believe that the current state is
> > not horrible. ;-)
>
> In that case, I think the comment above cleanup_srcu_struct_quiesced() in
> include/linux/srcu.h needs to be updated to cover situations where API
> users statically define a SRCU domain in a module and intend to unload
> that module.
>
> Given that we end up doing the allocation/cleanup under the hood, the
> API users don't interact with init_srcu_struct() nor cleanup_srcu_struct(),
> so it's not obvious that this comment also applies to them.
Actually, it turned out that cleanup_srcu_struct_quiesced() is extremely
hard to use correctly, and maybe even impossible to use correctly.
So cleanup_srcu_struct_quiesced has been eliminated in current -rcu.
Thanx, Paul
> Thanks,
>
> Mathieu
>
> --
> Mathieu Desnoyers
> EfficiOS Inc.
> http://www.efficios.com
>
next prev parent reply other threads:[~2019-04-09 19:14 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-02 14:28 [PATCH RFC tip/core/rcu 0/4] Forbid static SRCU use in modules Paul E. McKenney
2019-04-02 14:29 ` [PATCH RFC tip/core/rcu 1/4] dax/super: Dynamically allocate dax_srcu Paul E. McKenney
2019-04-03 18:31 ` Dan Williams
2019-04-04 21:04 ` Paul E. McKenney
2019-04-02 14:29 ` [PATCH RFC tip/core/rcu 2/4] drivers/gpu/drm: Dynamically allocate drm_unplug_srcu Paul E. McKenney
2019-04-02 16:14 ` Daniel Vetter
2019-04-02 14:29 ` [PATCH RFC tip/core/rcu 3/4] drivers/gpu/drm/amd: Dynamically allocate kfd_processes_srcu Paul E. McKenney
2019-04-02 17:40 ` Kuehling, Felix
2019-04-04 21:16 ` Paul E. McKenney
2019-04-02 14:29 ` [PATCH RFC tip/core/rcu 4/4] rcu: Forbid DEFINE{,_STATIC}_SRCU() from modules Paul E. McKenney
2019-04-02 15:14 ` [PATCH RFC tip/core/rcu 0/4] Forbid static SRCU use in modules Mathieu Desnoyers
2019-04-02 15:23 ` Paul E. McKenney
2019-04-02 15:34 ` Mathieu Desnoyers
2019-04-03 13:32 ` Paul E. McKenney
2019-04-03 14:27 ` Mathieu Desnoyers
2019-04-03 16:20 ` Paul E. McKenney
2019-04-03 19:30 ` Joel Fernandes
2019-04-05 23:28 ` Paul E. McKenney
2019-04-06 13:33 ` Joel Fernandes
2019-04-07 13:48 ` Paul E. McKenney
2019-04-06 23:06 ` Joel Fernandes
2019-04-07 13:39 ` Paul E. McKenney
2019-04-07 13:59 ` Paul E. McKenney
2019-04-07 15:46 ` Joel Fernandes
2019-04-07 17:05 ` Paul E. McKenney
2019-04-08 0:36 ` Joel Fernandes
2019-04-08 2:28 ` Paul E. McKenney
2019-04-07 19:26 ` Mathieu Desnoyers
2019-04-07 19:32 ` Joel Fernandes
2019-04-07 20:41 ` Mathieu Desnoyers
2019-04-07 21:07 ` Joel Fernandes
2019-04-08 2:27 ` Paul E. McKenney
2019-04-08 13:05 ` Mathieu Desnoyers
2019-04-08 14:22 ` Paul E. McKenney
2019-04-08 14:49 ` Mathieu Desnoyers
2019-04-08 15:46 ` Paul E. McKenney
2019-04-08 17:24 ` Mathieu Desnoyers
2019-04-09 15:40 ` Joel Fernandes
2019-04-09 15:56 ` Mathieu Desnoyers
2019-04-09 16:18 ` Joel Fernandes
2019-04-09 16:40 ` Paul E. McKenney
2019-04-09 16:45 ` Mathieu Desnoyers
2019-04-09 17:55 ` Paul E. McKenney
2019-04-09 18:04 ` Mathieu Desnoyers
2019-04-09 19:14 ` Paul E. McKenney [this message]
2019-04-02 18:40 ` Joel Fernandes
2019-04-03 13:19 ` Paul E. McKenney
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