Why does disk I/O slow down a CPU bound task?

[Reindl Harald]

Am 01.04.2015 um 19:36 schrieb Dave Johansen:
> On Wed, Apr 1, 2015 at 1:32 AM, Reindl Harald wrote:
>
>     Am 01.04.2015 um 06:53 schrieb Dave Johansen:
>
>         I added the call to mlockall() (it did have to be run as root)
>         on a F21
>         machine with no swap and the slow down was still visible in the "CPU
>         bound task"
>
>     surely, as expected
>
>     http://serverfault.com/questions/12679/can-anyone-explain-precisely-what-iowait-is
>
> I don't get how that is expected. The "CPU bound task" is now basically
> guaranteed to not be doing anything that requires disk access, so the
> iowait should be 0 for the "CPU bound task"

the purpose of mlockall() was not to solve the problem, it's intention 
is only to reduce side-effects in the test scenario

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