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Re: Fresh checkout vs 'svn upgrade': How good is good enough?

From: Philip Martin <philip.martin_at_wandisco.com>
Date: Wed, 08 Jun 2011 09:07:41 +0100

Philip Martin <philip.martin_at_wandisco.com> writes:

> Upgrade can be faster or slower than checkout, it depends on what one
> measures. I am using trunk as my data set, rather than 1.6.17, and I am
> checking out from a local mirror across my LAN.
>
> Checkout with 1.6 is about 9s elapsed, 6s CPU.
> Checkout with 1.7 is about the same.
> Upgrade with 1.7 is about 4s elapsed, 4s CPU.
>
> So upgrade is clearly faster than checkout.
>
> But wait! I get the numbers above by running upgrade directly after
> checkout, which means the the 1.6 working copy is in the client
> machine's OS cache (the client is a Linux laptop with a standard,
> rotating, SATA disk). If I drop the OS cache between checkout and
> upgrade then:
>
> Upgrade with 1.7 is about 15s elapsed, 4s CPU.
>
> Upgrade is clearly slower than checkout.
>
> In this case upgrade always uses less CPU, so it is in some sense more
> efficient, but it's not really possible to say whether it is faster or
> slower.

Those checkout values are with a hot cache on the server. When the
server has to wait for the disk (it's a standard desktop, rotating, SATA
disk) the checkout is much slower:

   Checkout with 1.7 is about 120s elapsed, 9s CPU

-- 
Philip
Received on 2011-06-08 10:08:20 CEST

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