From: Christoffer Dall <christoffer.dall@linaro.org>
To: Shanker Donthineni <shankerd@codeaurora.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
kvmarm <kvmarm@lists.cs.columbia.edu>,
Paolo Bonzini <pbonzini@redhat.com>,
Will Deacon <will.deacon@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
James Morse <james.morse@arm.com>
Subject: Re: [PATCH] arm64: KVM: Save two instructions in __guest_enter()
Date: Thu, 25 Aug 2016 15:31:22 +0200 [thread overview]
Message-ID: <20160825133122.GA8016@lvm> (raw)
In-Reply-To: <1470791736-13949-1-git-send-email-shankerd@codeaurora.org>
Hi Shanker,
On Tue, Aug 09, 2016 at 08:15:36PM -0500, Shanker Donthineni wrote:
> We are doing an unnecessary stack push/pop operation when restoring
> the guest registers x0-x18 in __guest_enter(). This patch saves the
> two instructions by using x18 as a base register. No need to store
> the vcpu context pointer in stack because it is redundant and not
> being used anywhere, the same information is available in tpidr_el2.
Does this have any measureable benefit?
Thanks,
-Christoffer
WARNING: multiple messages have this Message-ID (diff)
From: christoffer.dall@linaro.org (Christoffer Dall)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm64: KVM: Save two instructions in __guest_enter()
Date: Thu, 25 Aug 2016 15:31:22 +0200 [thread overview]
Message-ID: <20160825133122.GA8016@lvm> (raw)
In-Reply-To: <1470791736-13949-1-git-send-email-shankerd@codeaurora.org>
Hi Shanker,
On Tue, Aug 09, 2016 at 08:15:36PM -0500, Shanker Donthineni wrote:
> We are doing an unnecessary stack push/pop operation when restoring
> the guest registers x0-x18 in __guest_enter(). This patch saves the
> two instructions by using x18 as a base register. No need to store
> the vcpu context pointer in stack because it is redundant and not
> being used anywhere, the same information is available in tpidr_el2.
Does this have any measureable benefit?
Thanks,
-Christoffer
next prev parent reply other threads:[~2016-08-25 13:31 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-10 1:15 [PATCH] arm64: KVM: Save two instructions in __guest_enter() Shanker Donthineni
2016-08-10 1:15 ` Shanker Donthineni
2016-08-10 1:15 ` Shanker Donthineni
2016-08-25 13:31 ` Christoffer Dall [this message]
2016-08-25 13:31 ` Christoffer Dall
2016-08-29 15:22 ` Shanker Donthineni
2016-08-29 15:22 ` Shanker Donthineni
2016-08-29 15:22 ` Shanker Donthineni
2016-08-29 18:15 ` Christoffer Dall
2016-08-29 18:15 ` Christoffer Dall
2016-08-29 18:15 ` Christoffer Dall
2016-08-29 18:13 ` Christoffer Dall
2016-08-29 18:13 ` Christoffer Dall
2016-08-29 18:13 ` Christoffer Dall
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