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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Josh Cartwright <joshc@ni.com>
Cc: "Jaggi, Manish" <Manish.Jaggi@caviumnetworks.com>,
	linux-rt-users <linux-rt-users@vger.kernel.org>,
	Christoffer Dall <christoffer.dall@linaro.org>
Subject: Re: [PATCH -rt 2/2] KVM: arm/arm64: downgrade preempt_disable()d region to migrate_disable()
Date: Sat, 13 Feb 2016 00:03:19 +0100	[thread overview]
Message-ID: <20160212230319.GA7694@linutronix.de> (raw)
In-Reply-To: <685c494e87e1b537881117a5098bc4b3447b3add.1455213062.git.joshc@ni.com>

* Josh Cartwright | 2016-02-11 11:54:01 [-0600]:

>kvm_arch_vcpu_ioctl_run() disables the use of preemption when updating
>the vgic and timer states to prevent the calling task from migrating to
>another CPU.  It does so to prevent the task from writing to the
>incorrect per-CPU GIC distributor registers.
>
>On -rt kernels, it's possible to maintain the same guarantee with the
>use of migrate_{disable,enable}(), with the added benefit that the
>migrate-disabled region is preemptible.  Update
>kvm_arch_vcpu_ioctl_run() to do so.
>
>Cc: Christoffer Dall <christoffer.dall@linaro.org>
>Reported-by: Manish Jaggi <Manish.Jaggi@caviumnetworks.com>
>Signed-off-by: Josh Cartwright <joshc@ni.com>

Thanks, applied.

Sebastian

      reply	other threads:[~2016-02-12 23:03 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-10  9:33 [4.4rt3] Preemption disabled at:[<ffff8000000aba44>] kvm_vcpu_ioctl+0x30c/0x750 Jaggi, Manish
2016-02-10 16:39 ` Josh Cartwright
2016-02-11 10:46   ` Jaggi, Manish
2016-02-11 14:02     ` Christoffer Dall
2016-02-11 16:19       ` Marc Zyngier
2016-02-11 15:28     ` Sebastian Andrzej Siewior
2016-02-11 15:31       ` Jaggi, Manish
2016-02-11 14:01   ` Christoffer Dall
2016-02-11 16:10   ` Sebastian Andrzej Siewior
2016-02-11 17:54     ` [PATCH -rt 1/2] genirq: update irq_set_irqchip_state documentation Josh Cartwright
2016-02-11 17:54       ` [PATCH -rt 2/2] KVM: arm/arm64: downgrade preempt_disable()d region to migrate_disable() Josh Cartwright
2016-02-12 23:03         ` Sebastian Andrzej Siewior [this message]

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