From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: ARM: Disable preemption along with interrupts during shutdown
Date: Thu, 8 May 2014 14:49:10 +0100 [thread overview]
Message-ID: <20140508134910.GF3693@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <1399555411-15330-1-git-send-email-arunks.linux@gmail.com>
On Thu, May 08, 2014 at 06:53:31PM +0530, arunks.linux at gmail.com wrote:
> From: Arun KS <arunks.linux@gmail.com>
>
> 'irqs disabled' is funtamentally unsafe way of disabling preemption.
> Any spin_unlock() decreasing the preemption count to 0 might trigger
> a reschedule. A simple printk() might trigger a reschedule.
>
> To be on safe side disable preemption as well using preempt_disable()
NAK.
asmlinkage void __sched notrace preempt_schedule(void)
{
/*
* If there is a non-zero preempt_count or interrupts are disabled,
* we do not want to preempt the current task. Just return..
*/
if (likely(!preemptible()))
return;
--
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.
next prev parent reply other threads:[~2014-05-08 13:49 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-08 13:23 ARM: Disable preemption along with interrupts during shutdown arunks.linux at gmail.com
2014-05-08 13:49 ` Russell King - ARM Linux [this message]
2014-05-08 14:16 ` Arun KS
2014-05-08 15:22 ` Russell King - ARM Linux
2014-05-09 2:43 ` Arun KS
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