And Here I Thought buildworld/makeworld Was IO Bound

[Tim Daneliuk]

On 02/11/2014 03:57 PM, Andrew J. Caines wrote:
> On 02/11/2014 01:50 PM, Tim Daneliuk wrote:
>> does buildworld/kernel even use /tmp or otherwise access tmpfs?   It
>> seems to produce temporary output somewhere deep in /usr/obj.   Is
>> there a way to get it to use tmpfs or write it's output to /tmp
>> instead?
>
> I've been using a mfs for /usr/obj and WRKDIRPREFIX for ports for years.
>
> md  /usr/obj   mfs  rw,async,noatime,noauto,-s6g  0  0
> md  /var/work  mfs  rw,async,noatime,noauto,-s2g  0  0
>
> Makes cleanup quick and easy, too.
>
>

Final Results:

I did a number of different timings including symlinking  /usr/obj
to /tmp/obj when /tmp is a tmfs as well as mounting /usr/obj on an md
as suggested above.  In all cases, the time to do the buildworld/kernels
was about the same.

So, I conclude the following:

    When running on an SSD, at least the one I am using, the performance
    is bounded by CPU, not disk.


Many thanks to all who took the time to answer my stupid questions ...

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Tim Daneliuk     tundra at tundraware.com
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