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From: christoffer.dall@linaro.org (Christoffer Dall)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/8] arm64: KVM: Switch the sys_reg search to be a binary search
Date: Wed, 10 Feb 2016 13:44:28 +0100	[thread overview]
Message-ID: <20160210124428.GH5171@cbox> (raw)
In-Reply-To: <1454931622-14902-2-git-send-email-marc.zyngier@arm.com>

On Mon, Feb 08, 2016 at 11:40:15AM +0000, Marc Zyngier wrote:
> Our 64bit sys_reg table is about 90 entries long (so far, and the
> PMU support is likely to increase this). This means that on average,
> it takes 45 comparaisons to find the right entry (and actually the
> full 90 if we have to search the invariant table).
> 
> Not the most efficient thing. Specially when you think that this
> table is already sorted. Switching to a binary search effectively
> reduces the search to about 7 comparaisons. Slightly better!
> 
> As an added bonus, the comparaison is done by comparing all the

s/comparaison/comparison/

> fields at once, instead of one at a time.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>

  reply	other threads:[~2016-02-10 12:44 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-08 11:40 [PATCH 0/8] KVM/ARM: Guest Entry/Exit optimizations Marc Zyngier
2016-02-08 11:40 ` [PATCH 1/8] arm64: KVM: Switch the sys_reg search to be a binary search Marc Zyngier
2016-02-10 12:44   ` Christoffer Dall [this message]
2016-02-10 13:49   ` Alex Bennée
2016-02-10 14:00     ` Marc Zyngier
2016-02-08 11:40 ` [PATCH 2/8] ARM: KVM: Properly sort the invariant table Marc Zyngier
2016-02-10 12:44   ` Christoffer Dall
2016-02-08 11:40 ` [PATCH 3/8] ARM: KVM: Enforce sorting of all CP tables Marc Zyngier
2016-02-10 12:44   ` Christoffer Dall
2016-02-08 11:40 ` [PATCH 4/8] ARM: KVM: Rename struct coproc_reg::is_64 to is_64bit Marc Zyngier
2016-02-10 12:44   ` Christoffer Dall
2016-02-08 11:40 ` [PATCH 5/8] ARM: KVM: Switch the CP reg search to be a binary search Marc Zyngier
2016-02-10 12:44   ` Christoffer Dall
2016-02-08 11:40 ` [PATCH 6/8] KVM: arm/arm64: timer: Add active state caching Marc Zyngier
2016-02-10 12:44   ` Christoffer Dall
2016-02-08 11:40 ` [PATCH 7/8] KVM: arm/arm64: Avoid accessing GICH registers Marc Zyngier
2016-02-10 12:45   ` Christoffer Dall
2016-02-10 13:34     ` Marc Zyngier
2016-02-10 17:30       ` Christoffer Dall
2016-02-10 17:43         ` Marc Zyngier
2016-02-08 11:40 ` [PATCH 8/8] KVM: arm64: Avoid accessing ICH registers Marc Zyngier
2016-02-10 12:45   ` Christoffer Dall
2016-02-10 16:47     ` Marc Zyngier
2016-02-09 20:59 ` [PATCH 0/8] KVM/ARM: Guest Entry/Exit optimizations Christoffer Dall
2016-02-10  8:34   ` Marc Zyngier
2016-02-10 12:02     ` Andrew Jones
2016-02-10 12:24       ` Marc Zyngier
2016-02-10 20:40 ` Christoffer Dall
2016-02-16 20:05   ` Marc Zyngier
2016-02-17  9:15     ` Christoffer Dall

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