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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>,
	Anna-Maria Behnsen <anna-maria@linutronix.de>
Subject: [PATCH 0/6] timers/migration: Fix NUMA trees + cleanups
Date: Fri, 24 Oct 2025 15:25:30 +0200	[thread overview]
Message-ID: <20251024132536.39841-1-frederic@kernel.org> (raw)

Hi,

A while ago I found out that NUMA tree layout had flaws but I thought it
was only about rare setups. Having had a closer look while thinking
about the big.LITTLE handling, I realized the NUMA timer tree are
actually imbalanced in many cases, except perhaps when 0-7 CPUs are lucky
enough to belong to the same node, and yet up to a certain amount of
CPUs.

Here is a fix proposal, plus a bunch of cleanups.

git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
	timers/core

HEAD: 4adecc004d35dbe8a48df3d23ed2b8cf42772716
Thanks,
	Frederic
---

Frederic Weisbecker (6):
      timers/migration: Convert "while" loops to use "for"
      timers/migration: Remove locking on group connection
      timers/migration: Fix imbalanced NUMA trees
      timers/migration: Assert that hotplug preparing CPU is part of stable active hierarchy
      timers/migration: Remove unused "cpu" parameter from tmigr_get_group()
      timers/migration: Remove dead code handling idle CPU checking for remote timers

 kernel/time/timer_migration.c | 279 ++++++++++++++++++++++--------------------
 1 file changed, 143 insertions(+), 136 deletions(-)

             reply	other threads:[~2025-10-24 13:25 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-24 13:25 Frederic Weisbecker [this message]
2025-10-24 13:25 ` [PATCH 1/6] timers/migration: Convert "while" loops to use "for" Frederic Weisbecker
2025-11-01 19:41   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2025-10-24 13:25 ` [PATCH 2/6] timers/migration: Remove locking on group connection Frederic Weisbecker
2025-11-01 19:41   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2025-10-24 13:25 ` [PATCH 3/6] timers/migration: Fix imbalanced NUMA trees Frederic Weisbecker
2025-11-01 19:41   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2025-10-24 13:25 ` [PATCH 4/6] timers/migration: Assert that hotplug preparing CPU is part of stable active hierarchy Frederic Weisbecker
2025-11-01 19:41   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2025-10-24 13:25 ` [PATCH 5/6] timers/migration: Remove unused "cpu" parameter from tmigr_get_group() Frederic Weisbecker
2025-11-01 19:41   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker
2025-10-24 13:25 ` [PATCH 6/6] timers/migration: Remove dead code handling idle CPU checking for remote timers Frederic Weisbecker
2025-11-01 19:41   ` [tip: timers/core] " tip-bot2 for Frederic Weisbecker

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