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From: "Paul E. McKenney" <paulmck@kernel.org>
To: bigeasy@linutronix.de
Cc: linux-kernel@vger.kernel.org, rcu@vger.kernel.org
Subject: Should RCU_BOOST kernels use hrtimers in GP kthread?
Date: Tue, 16 Feb 2021 10:36:09 -0800	[thread overview]
Message-ID: <20210216183609.GA7027@paulmck-ThinkPad-P72> (raw)

Hello, Sebastian,

I punted on this for the moment by making RCU priority boosting testing
depend on CONFIG_PREEMPT_RT, but longer term I am wondering if RCU's
various timed delays and timeouts should use hrtimers rather than normal
timers in kernels built with CONFIG_RCU_BOOST.  As it is, RCU priority
boosting can be defeated if any of the RCU grace-period kthread's timeouts
are serviced by the non-realtime ksoftirqd.

This might require things like swait_event_idle_hrtimeout_exclusive(),
either as primitives or just open coded.

Thoughts?

							Thanx, Paul

             reply	other threads:[~2021-02-16 18:37 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-16 18:36 Paul E. McKenney [this message]
2021-02-17 15:32 ` Should RCU_BOOST kernels use hrtimers in GP kthread? Sebastian Andrzej Siewior
2021-02-17 15:54   ` Paul E. McKenney
2021-02-17 17:01     ` Paul E. McKenney
2021-02-17 18:01     ` Sebastian Andrzej Siewior
2021-02-17 19:19       ` Paul E. McKenney
2021-02-17 19:43         ` Sebastian Andrzej Siewior
2021-04-14 23:48           ` Paul E. McKenney

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