[PATCH 1/8] arm64: KVM: Switch the sys_reg search to be a binary search

Christoffer Dall christoffer.dall at linaro.org
Wed Feb 10 04:44:28 PST 2016


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 at arm.com>

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



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