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

[reed kotler]

On 07/25/2013 02:47 PM, 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.
>
Sounds like a good plan.

We will make that change.

>  - Daniel
>
>
> On Wed, Jul 24, 2013 at 11:37 AM, Doug Gilmore 
> <Doug.Gilmore at imgtec.com <mailto: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 <http://mips.com>
>     > > <mailto:rkotler <mailto:rkotler> at mips.com
>     <http://mips.com>>> wrote:
>     > > ...
>
>
>

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