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Date: Thu, 8 Oct 2015 22:21:18 +0530
From: Pratyush Anand <panand@redhat.com>
To: Jungseok Lee <jungseoklee85@gmail.com>
Cc: catalin.marinas@arm.com, will.deacon@arm.com,
        linux-arm-kernel@lists.infradead.org, james.morse@arm.com,
        takahiro.akashi@linaro.org, mark.rutland@arm.com, barami97@gmail.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 1/2] arm64: Introduce IRQ stack
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Hi Jungseok,

On 08/10/2015:11:32:43 PM, Jungseok Lee wrote:
> On Oct 8, 2015, at 7:25 PM, Pratyush Anand wrote:
> > Hi Jungseok,
> 
> Hi Pratyush,
> 
> > 
> > On 07/10/2015:03:28:11 PM, Jungseok Lee wrote:
> >> Currently, kernel context and interrupts are handled using a single
> >> kernel stack navigated by sp_el1. This forces a system to use 16KB
> >> stack, not 8KB one. This restriction makes low memory platforms suffer
> >> from memory pressure accompanied by performance degradation.
> > 
> > How will it behave on 64K Page system? There, it would take atleast 64K per cpu,
> > right?
> 
> It would take 16KB per cpu even on 64KB page system.
> The following code snippet from kernel/fork.c would be helpful.

Yes..Yes..its understood.
Thanks for pointing to the code.

~Pratyush