Linux RCU subsystem development
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From: Frederic Weisbecker <frederic@kernel.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Frederic Weisbecker <frederic@kernel.org>,
	vlad.wing@gmail.com, rcu@vger.kernel.org, boqun.feng@gmail.com,
	joel@joelfernandes.org, neeraj.upadhyay@amd.com,
	urezki@gmail.com, qiang.zhang1211@gmail.com,
	Cheng-Jui.Wang@mediatek.com, leitao@debian.org,
	kernel-team@meta.com, Usama Arif <usamaarif642@gmail.com>,
	paulmck@kernel.org, Anna-Maria Behnsen <anna-maria@linutronix.de>
Subject: [PATCH 0/3] hrtimer: Fix timers queued locally from offline CPUs
Date: Wed, 18 Dec 2024 17:50:05 +0100	[thread overview]
Message-ID: <20241218165008.37820-1-frederic@kernel.org> (raw)

5c0930ccaad5 ("hrtimers: Push pending hrtimers away from outgoing CPU earlier")
was introduced to fix stalls with scheduler bandwidth timers getting
migrated while some kthreads handling CPU hotplug rely on bandwidth.

However this has introduced several other issues which used to be
confined to RCU. But not anymore as it is spreading to hotplug code
itself (https://lore.kernel.org/all/20241213203739.1519801-1-usamaarif642@gmail.com/)

Instead of introducing yet another new hackery, fix the problem in
hrtimers for everyone.

Frederic Weisbecker (3):
  hrtimers: Force migrate away hrtimers queued after
    CPUHP_AP_HRTIMERS_DYING
  rcu: Remove swake_up_one_online() bandaid
  Revert "rcu/nocb: Fix rcuog wake-up from offline softirq"

 include/linux/hrtimer_defs.h |  1 +
 kernel/rcu/tree.c            | 34 +-------------------
 kernel/rcu/tree_exp.h        |  2 +-
 kernel/rcu/tree_nocb.h       | 10 ++----
 kernel/time/hrtimer.c        | 60 +++++++++++++++++++++++++++++++-----
 5 files changed, 58 insertions(+), 49 deletions(-)

-- 
2.46.0


             reply	other threads:[~2024-12-18 16:50 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-12-18 16:50 Frederic Weisbecker [this message]
2024-12-18 16:50 ` [PATCH 1/3] hrtimers: Force migrate away hrtimers queued after CPUHP_AP_HRTIMERS_DYING Frederic Weisbecker
2024-12-19 19:00   ` Usama Arif
2024-12-20 23:43     ` Frederic Weisbecker
2024-12-18 16:50 ` [PATCH 2/3] rcu: Remove swake_up_one_online() bandaid Frederic Weisbecker
2024-12-18 16:50 ` [PATCH 3/3] Revert "rcu/nocb: Fix rcuog wake-up from offline softirq" Frederic Weisbecker
2024-12-19 17:42 ` [PATCH 0/3] hrtimer: Fix timers queued locally from offline CPUs Paul E. McKenney
2024-12-20 23:19   ` Paul E. McKenney
2024-12-20 23:26     ` Frederic Weisbecker
2024-12-21  0:05       ` Paul E. McKenney

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