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From: Davidlohr Bueso <dave@stgolabs.net>
To: tglx@linutronix.de
Cc: peterz@infradead.org, mingo@kernel.org, rostedt@goodmis.org,
	longman@redhat.com, bigeasy@linutronix.de, boqun.feng@gmail.com,
	linux-kernel@vger.kernel.org, Davidlohr Bueso <dbueso@suse.de>
Subject: Re: [PATCH 2/2] locking/rwbase_rt: Lockless reader waking up a writer
Date: Wed, 1 Sep 2021 16:03:20 -0700	[thread overview]
Message-ID: <20210901230320.3pogmlyzfgwpvw77@offworld> (raw)
In-Reply-To: <20210901222825.6313-3-dave@stgolabs.net>

On Wed, 01 Sep 2021, Bueso wrote:

>As with the rest of our sleeping locks, use a wake_q to
>allow waking up the writer without having to hold the
>wait_lock across the operation. While this is ideally
>for batching wakeups, single wakeup usage as still shown
>to be beneficial vs the cost of try_to_wakeup when the
>lock is contended.
>
>Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
>---
> kernel/locking/rwbase_rt.c |  4 +++-
> kernel/sched/core.c        | 16 +++++++++++++---

Bleh, this of course is missing:

diff --git a/include/linux/sched/wake_q.h b/include/linux/sched/wake_q.h
index 06cd8fb2f409..695efd987b56 100644
--- a/include/linux/sched/wake_q.h
+++ b/include/linux/sched/wake_q.h
@@ -62,5 +62,6 @@ static inline bool wake_q_empty(struct wake_q_head *head)
  extern void wake_q_add(struct wake_q_head *head, struct task_struct *task);
  extern void wake_q_add_safe(struct wake_q_head *head, struct task_struct *task);
  extern void wake_up_q(struct wake_q_head *head);
+extern void wake_up_q_state(struct wake_q_head *head, unsigned int state);
  
  #endif /* _LINUX_SCHED_WAKE_Q_H */

  reply	other threads:[~2021-09-01 23:03 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-01 22:28 [PATCH 0/2] locking/rwbase_rt: Use wake_q for lockless reader waker Davidlohr Bueso
2021-09-01 22:28 ` [PATCH 1/2] sched: Move wake_q code below try_to_wake_up() Davidlohr Bueso
2021-09-01 22:28 ` [PATCH 2/2] locking/rwbase_rt: Lockless reader waking up a writer Davidlohr Bueso
2021-09-01 23:03   ` Davidlohr Bueso [this message]
2021-09-03 10:55   ` Sebastian Andrzej Siewior
2021-09-13 12:20   ` Thomas Gleixner
2021-09-14 10:42     ` Thomas Gleixner
2021-09-16 17:02       ` Sebastian Andrzej Siewior
2021-09-16 17:27         ` Davidlohr Bueso

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