[PATCHv2 0/5] arm64/irqentry: remove duplicate housekeeping of

From: Pingfan Liu <kernelfans@gmail.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Pingfan Liu <kernelfans@gmail.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Marc Zyngier <maz@kernel.org>, Joey Gouly <joey.gouly@arm.com>,
	Sami Tolvanen <samitolvanen@google.com>,
	Julien Thierry <julien.thierry@arm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Yuichi Ito <ito-yuichi@fujitsu.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCHv2 0/5] arm64/irqentry: remove duplicate housekeeping of
Date: Fri, 24 Sep 2021 21:28:32 +0800	[thread overview]
Message-ID: <20210924132837.45994-1-kernelfans@gmail.com> (raw)

After introducing arm64/kernel/entry_common.c which is akin to
kernel/entry/common.c , the housekeeping of rcu/trace are done twice as
the following:
    enter_from_kernel_mode()->rcu_irq_enter().
And
    gic_handle_irq()->...->handle_domain_irq()->irq_enter()->rcu_irq_enter()

Besides redundance, based on code analysis, the redundance also raise
some mistake, e.g.  rcu_data->dynticks_nmi_nesting inc 2, which causes
rcu_is_cpu_rrupt_from_idle() unexpected.

Nmi also faces duplicate accounts. This series aims to address these
duplicate issues.
[1-2/5]: address nmi account duplicate
[3-4/5]: address rcu housekeeping duplicate in irq
[5/5]: as a natural result of [3-4/5], address a history issue. [1]

History:
v1 -> v2:
    change the subject as the motivation varies.
    add the fix for nmi account duplicate

The subject of v1 is "[PATCH 1/3] kernel/irq: __handle_domain_irq()
makes irq_enter/exit arch optional". [2] It is brought up to fix [1].

There have been some tries to enable crash-stop-NMI on arm64, one by me,
the other by Yuichi's [4].  I hope after this series, they can advance,
as Marc said in [3] "No additional NMI patches will make it until we
have resolved the issues"

[1] https://lore.kernel.org/linux-arm-kernel/87lfewnmdz.fsf@nanos.tec.linutronix.de/
[2] https://lore.kernel.org/linux-arm-kernel/1607912752-12481-1-git-send-email-kernelfans@gmail.com
[3] https://lore.kernel.org/linux-arm-kernel/afd82be798cb55fd2f96940db7be78c0@kernel.org
[4] https://lore.kernel.org/linux-arm-kernel/20201104080539.3205889-1-ito-yuichi@fujitsu.com

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Julien Thierry <julien.thierry@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yuichi Ito <ito-yuichi@fujitsu.com>
Cc: linux-kernel@vger.kernel.org
To: linux-arm-kernel@lists.infradead.org

Pingfan Liu (5):
  arm64/entry-common: push the judgement of nmi ahead
  irqchip/GICv3: expose handle_nmi() directly
  kernel/irq: make irq_{enter,exit}() in handle_domain_irq() arch
    optional
  irqchip/GICv3: let gic_handle_irq() utilize irqentry on arm64
  irqchip/GICv3: make reschedule-ipi light weight

 arch/arm64/Kconfig               |  1 +
 arch/arm64/include/asm/irq.h     |  7 ++++
 arch/arm64/kernel/entry-common.c | 45 +++++++++++++++-------
 arch/arm64/kernel/irq.c          | 29 ++++++++++++++
 drivers/irqchip/irq-gic-v3.c     | 66 ++++++++++++++++++++------------
 kernel/irq/Kconfig               |  3 ++
 kernel/irq/irqdesc.c             |  4 ++
 7 files changed, 116 insertions(+), 39 deletions(-)

-- 
2.31.1

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