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Date: Mon, 2 Jan 2012 17:38:02 -0800
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From: Garrett Cooper <yanegomi@gmail.com>
To: Dieter BSD <dieterbsd@engineer.com>
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Cc: freebsd-performance@freebsd.org
Subject: Re: cmp(1) has a bottleneck, but where?
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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. =A0Cp runs as expected, but
>>> cmp runs slower than expected. =A0Neither the disks
>>> nor the cpu is maxed out. =A0Local drives, no network
>>> involved. =A0Machine is otherwise idle.
>>
>> =A0 =A01. How are you running cmp?
>> =A0 =A02. 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. =A0It isn't cpu bound ( 67.5%Idle )
> but it isn't disk bound either. =A0Seems like it should be one or the
> other.

    What gets output on the console when you do CTRL-T?
Thanks,
-Garrett