From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoffer Dall <christoffer.dall@linaro.org>
Subject: Re: [PATCH v4 03/40] KVM: arm64: Avoid storing the vcpu pointer on
 the stack
Date: Thu, 22 Feb 2018 11:24:18 +0100
Message-ID: <20180222102418.GK29376@cbox>
References: <20180215210332.8648-1-christoffer.dall@linaro.org>
 <20180215210332.8648-4-christoffer.dall@linaro.org>
 <20180221173200.6vfv6a4hytibos3p@kamzik.brq.redhat.com>
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 Marc Zyngier <marc.zyngier@arm.com>, kvmarm@lists.cs.columbia.edu,
 Yury Norov <ynorov@caviumnetworks.com>, linux-arm-kernel@lists.infradead.org,
 Dave Martin <Dave.Martin@arm.com>, Shih-Wei Li <shihwei@cs.columbia.edu>
To: Andrew Jones <drjones@redhat.com>
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On Thu, Feb 22, 2018 at 10:56:41AM +0100, Andrew Jones wrote:
> On Thu, Feb 22, 2018 at 10:10:34AM +0100, Christoffer Dall wrote:
> > On Wed, Feb 21, 2018 at 06:32:00PM +0100, Andrew Jones wrote:
> > > 
> > > Besides my confusion on motivation, it looks good to me
> > > 
> > 
> > In that case, unless there's an argument that the code has become too
> > hard to understand, ...
> >
> 
> On the contrary, I think it's easier to read now than before. I just
> wasn't clear how it all tied together with this series. If its
> combination with other patches enables a speedup, then it certainly
> fits here. I was just comparing mrs+loads vs. a load from stack and

The comparison should be mrs+load, vs. str+load (you save the store on
the stack).

> it seemed it would actually cause a micro-performance-decrease.
> 

Thanks,
-Christoffer

From mboxrd@z Thu Jan  1 00:00:00 1970
From: christoffer.dall@linaro.org (Christoffer Dall)
Date: Thu, 22 Feb 2018 11:24:18 +0100
Subject: [PATCH v4 03/40] KVM: arm64: Avoid storing the vcpu pointer on
 the stack
In-Reply-To: <20180222095641.w5isy5jt5a67jocp@kamzik.brq.redhat.com>
References: <20180215210332.8648-1-christoffer.dall@linaro.org>
 <20180215210332.8648-4-christoffer.dall@linaro.org>
 <20180221173200.6vfv6a4hytibos3p@kamzik.brq.redhat.com>
 <20180222091034.GD29376@cbox>
 <20180222095641.w5isy5jt5a67jocp@kamzik.brq.redhat.com>
Message-ID: <20180222102418.GK29376@cbox>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Thu, Feb 22, 2018 at 10:56:41AM +0100, Andrew Jones wrote:
> On Thu, Feb 22, 2018 at 10:10:34AM +0100, Christoffer Dall wrote:
> > On Wed, Feb 21, 2018 at 06:32:00PM +0100, Andrew Jones wrote:
> > > 
> > > Besides my confusion on motivation, it looks good to me
> > > 
> > 
> > In that case, unless there's an argument that the code has become too
> > hard to understand, ...
> >
> 
> On the contrary, I think it's easier to read now than before. I just
> wasn't clear how it all tied together with this series. If its
> combination with other patches enables a speedup, then it certainly
> fits here. I was just comparing mrs+loads vs. a load from stack and

The comparison should be mrs+load, vs. str+load (you save the store on
the stack).

> it seemed it would actually cause a micro-performance-decrease.
> 

Thanks,
-Christoffer