Date: Mon, 2 Jan 2012 17:38:02 -0800 From: Garrett Cooper <yanegomi@gmail.com> To: Dieter BSD <dieterbsd@engineer.com> Cc: freebsd-performance@freebsd.org Subject: Re: cmp(1) has a bottleneck, but where? Message-ID: <CAGH67wR1WFxJWamXpz8wVLMdh5YrN_%2BktjOqU_PqdNHmQyZ51w@mail.gmail.com> In-Reply-To: <20120103012929.218270@gmx.com>
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On Mon, Jan 2, 2012 at 5:29 PM, Dieter BSD <dieterbsd@engineer.com> wrote:
>>> Task: cp(1) a several-GB file from one drive to another,
>>> then run cmp(1) to verify. Cp runs as expected, but
>>> cmp runs slower than expected. Neither the disks
>>> nor the cpu is maxed out. Local drives, no network
>>> involved. Machine is otherwise idle.
>>
>> 1. How are you running cmp?
>> 2. Why do you claim cmp is the bottleneck? Is it spinning the CPU?
>
> cmp big_file /other_disk/big_file
>
> Cmp is running slower than it should. It isn't cpu bound ( 67.5%Idle )
> but it isn't disk bound either. Seems like it should be one or the
> other.
What gets output on the console when you do CTRL-T?
Thanks,
-Garrett
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