[PATCH 0/3] sched: migrate_disable() vs per-CPU access safety checks

From: Valentin Schneider <valentin.schneider@arm.com>
To: linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-rt-users@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Steven Rostedt <rostedt@goodmis.org>,
	Daniel Bristot de Oliveira <bristot@redhat.com>,
	"Paul E. McKenney" <paulmck@kernel.org>,
	Josh Triplett <josh@joshtriplett.org>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Lai Jiangshan <jiangshanlai@gmail.com>,
	Joel Fernandes <joel@joelfernandes.org>,
	Anshuman Khandual <anshuman.khandual@arm.com>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	Steven Price <steven.price@arm.com>,
	Ard Biesheuvel <ardb@kernel.org>
Subject: [PATCH 0/3] sched: migrate_disable() vs per-CPU access safety checks
Date: Wed, 21 Jul 2021 12:51:15 +0100	[thread overview]
Message-ID: <20210721115118.729943-1-valentin.schneider@arm.com> (raw)

Hi folks,

I've hit a few warnings when taking v5.13-rt1 out for a spin on my arm64
Juno. Those are due to regions that become preemptible under PREEMPT_RT, but
remain safe wrt per-CPU accesses due to migrate_disable() + a sleepable lock.

This adds a helper that looks at not just preemptability but also affinity and
migrate disable, and plasters the warning sites.

Cheers,
Valentin

Valentin Schneider (3):
  sched: Introduce is_pcpu_safe()
  rcu/nocb: Check for migratability rather than pure preemptability
  arm64: mm: Make arch_faults_on_old_pte() check for migratability

 arch/arm64/include/asm/pgtable.h |  2 +-
 include/linux/sched.h            | 10 ++++++++++
 kernel/rcu/tree_plugin.h         |  3 +--
 3 files changed, 12 insertions(+), 3 deletions(-)

--
2.25.1