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

[Daniel Dunbar]

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


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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