From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Will Deacon <will@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Josh Triplett <josh@joshtriplett.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
rcu@vger.kernel.org
Subject: Re: [PATCH 3/8] srcu: Use local_lock() for per-CPU struct srcu_data access
Date: Sat, 23 May 2020 17:08:31 +0200 [thread overview]
Message-ID: <20200523150831.wdrthklakwm6wago@linutronix.de> (raw)
In-Reply-To: <20200522173953.GI2869@paulmck-ThinkPad-P72>
On 2020-05-22 10:39:53 [-0700], Paul E. McKenney wrote:
> It looks good to me, but I have not yet tested it. (Happy to let you
> take the first crack at rcutorture in any case, scenarios SRCU-P and
> SRCU-N.)
on it.
> > That check_init_srcu_struct() is needed, because otherwise:
> >
> > | BUG: spinlock bad magic on CPU#2, swapper/0/1
> > | lock: 0xffff88803ed28ac0, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
> > | CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.7.0-rc6+ #81
> > | Call Trace:
> > | dump_stack+0x71/0xa0
> > | do_raw_spin_lock+0x6c/0xb0
> > | _raw_spin_lock_irqsave+0x33/0x40
> > | synchronize_srcu+0x24/0xc9
> > | wakeup_source_remove+0x4d/0x70
> > | wakeup_source_unregister.part.0+0x9/0x40
> > | device_wakeup_enable+0x99/0xc0
> >
> > I'm not sure if there should be an explicit init of `wakeup_srcu' or if
> > an srcu function (like call_srcu()) is supposed to do it.
>
> It is fine. Beforehand, that check_init_srcu_struct() would have been
> invoked very shortly thereafter from __call_srcu(), and there is no
> instead harm invoking it a few microseconds earlier. ;-)
Oki. I wasn't sure if an explizit initialized on wakeup_srcu's side was
missing or if this is new since we use the lock earlier.
> Thanx, Paul
Sebastian
next prev parent reply other threads:[~2020-05-23 15:08 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-19 20:19 [PATCH 0/8] Introduce local_lock() Sebastian Andrzej Siewior
2020-05-19 20:19 ` [PATCH 1/8] locking: " Sebastian Andrzej Siewior
2020-05-20 12:04 ` Peter Zijlstra
2020-05-22 11:05 ` Sebastian Andrzej Siewior
2020-05-22 13:01 ` Peter Zijlstra
2020-05-19 20:19 ` [PATCH 2/8] radix-tree: Use local_lock for protection Sebastian Andrzej Siewior
2020-05-19 20:45 ` Matthew Wilcox
2020-05-19 20:54 ` Steven Rostedt
2020-05-20 2:05 ` Matthew Wilcox
2020-05-20 10:13 ` Sebastian Andrzej Siewior
2020-05-20 10:21 ` Peter Zijlstra
2020-05-20 12:28 ` Thomas Gleixner
2020-05-19 20:19 ` [PATCH 3/8] srcu: Use local_lock() for per-CPU struct srcu_data access Sebastian Andrzej Siewior
2020-05-20 10:24 ` Peter Zijlstra
2020-05-20 12:06 ` Sebastian Andrzej Siewior
2020-05-20 13:27 ` Peter Zijlstra
2020-05-20 17:42 ` Joel Fernandes
2020-05-20 18:28 ` Sebastian Andrzej Siewior
2020-05-20 18:35 ` Peter Zijlstra
2020-05-20 18:44 ` Joel Fernandes
2020-05-20 18:50 ` Uladzislau Rezki
2020-05-20 18:59 ` Joel Fernandes
2020-05-20 18:43 ` Paul E. McKenney
2020-05-22 15:12 ` Sebastian Andrzej Siewior
2020-05-22 17:39 ` Paul E. McKenney
2020-05-23 15:08 ` Sebastian Andrzej Siewior [this message]
2020-05-23 16:59 ` Paul E. McKenney
2020-05-24 19:03 ` Sebastian Andrzej Siewior
2020-05-25 3:27 ` Paul E. McKenney
2020-05-26 13:41 ` [PATCH] srcu: Avoid local_irq_save() before acquiring spinlock_t Sebastian Andrzej Siewior
2020-05-26 16:16 ` Paul E. McKenney
2020-05-26 16:31 ` Sebastian Andrzej Siewior
2020-05-19 20:19 ` [PATCH 4/8] mm/swap: Use local_lock for protection Sebastian Andrzej Siewior
2020-05-19 23:58 ` Andrew Morton
2020-05-20 2:17 ` Matthew Wilcox
2020-05-20 10:53 ` Peter Zijlstra
2020-05-19 20:19 ` [PATCH 5/8] squashfs: make use of local lock in multi_cpu decompressor Sebastian Andrzej Siewior
2020-05-20 10:56 ` Peter Zijlstra
2020-05-19 20:19 ` [PATCH 6/8] connector/cn_proc: Protect send_msg() with a local lock Sebastian Andrzej Siewior
2020-05-20 11:03 ` Peter Zijlstra
2020-05-19 20:19 ` [PATCH 7/8] zram: Use local lock to protect per-CPU data Sebastian Andrzej Siewior
2020-05-20 11:07 ` Peter Zijlstra
2020-05-19 20:19 ` [PATCH 8/8] mm/zswap: " Sebastian Andrzej Siewior
2020-05-19 21:46 ` Song Bao Hua
2020-05-20 10:26 ` Sebastian Andrzej Siewior
2020-05-20 11:13 ` Song Bao Hua
2020-05-20 11:57 ` Sebastian Andrzej Siewior
2020-05-20 12:01 ` Song Bao Hua
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