[LNT][Patch] Bug 16261 - lnt incorrectly builds timeit-target when one is using a simulator

[Doug Gilmore]

On Thu, 2013-07-25 at 14:47 -0700, Daniel Dunbar wrote:
> Ok, this seems like a pretty custom situation, I'd rather that have
> minimal impact on the LNT code paths. It doesn't generally make any
> sense to compile "timeit-target" for the host.
> 
> 
> Could you instead implement this as a patch to instead cause "timeit"
> to be used instead of "timeit-target". This should be as simple as
> adding a new Makefile variable that will be used in Makefile.programs
> to cause RUNSAFELY to use timeit instead of timeit-target. Then you
> can use LNT's existing --make-param option to pass that in.
> 
> 
>  - Daniel
That's great -- my patch needed cleanup anyway and your approach
finesses that issue.

Patch attached.

Thanks!

Doug
> 
> 
> On Wed, Jul 24, 2013 at 11:37 AM, Doug Gilmore
> <Doug.Gilmore at imgtec.com> wrote:
>         On Tue, 2013-07-23 at 17:17 -0700, an Reed Kotler wrote:
>         >
>         > In this case we are not using lnt under Qemu user mode for
>         benchmarking;
>         > just as a way to run test-suite to test whether the code is
>         correct.
>         >
>         > Qemu user mode emulates target instructions, but when it
>         gets a Unix
>         > Kernel trap, it uses the host to emulate those.
>         >
>         > For example, file I/O.
>         >
>         > It is possible to run target timeit under qemu and let it
>         launch the app
>         > or a wrapper.
>         > (But it is more limited as to what can be done here under
>         qemu vs under
>         > the host OS directly).
>         >
>         > For time functions, it is also going to use the host to
>         emulate those.
>         >
>         > So whether timeit is running under qemu or directly on the
>         host, the
>         > answers regarding time will be the same.
>         >
>         > But running timeit under qemu will be much slower as far as
>         elapsed time
>         > than running it on the host directly.
>         >
>         > We would also need to add some new mechanism to Lnt or the
>         makefiles to
>         > also wrap timeit.
>         
>         Good point Reed -- thanks!
>         >
>         > Reed
>         >
>         >
>         > On 07/23/2013 02:19 PM, Daniel Dunbar wrote:
>         > > Wouldn't it be a more accurate simulation to run
>         timeit-target under
>         > > the emulator as well? Or is that too much to ask?
>         > >
>         > >  - Daniel
>         
>         Hi Daniel,
>         
>         I agree with Reed's discussion of the issues.  We are mainly
>         concerned with
>         the correctness when running under QEMU, though the the timing
>         data
>         might be useful at a very course grain level.
>         
>         Doug
>         > >
>         > >
>         > > On Mon, Jul 22, 2013 at 6:47 PM, Reed Kotler <rkotler at
>         mips.com
>         > > <mailto:rkotler at mips.com>> wrote:
>         > > ...
>         
>         
> 
> 

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