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From: Ivan Voras <ivoras@freebsd.org>
Date: Thu, 15 Aug 2013 22:29:24 +0200
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Subject: Re: svn commit: r254380 - in head/sys: kern sys
To: Colin Percival <cperciva@freebsd.org>
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On 15 August 2013 22:19, Colin Percival <cperciva@freebsd.org> wrote:

>   For workloads with R parallel reads and W parallel writes, this improves
>   the time spent from O((R+W)^2) to O(W*(R+W)); i.e., heavy parallel-read
>   workloads become significantly more scalable.
>
>   No statistically significant change in buildworld time has been measured,
>   but synthetic tests of parallel 'dd > /dev/null' and 'openssl enc >/dev/null'
>   with the input file cached yield dramatic (up to 10x) improvement with high
>   (up to 128 processes) levels of parallelism.

That's interesting. Have you tried running the "blogbench" benchmark
before & after?