Hi, Randy,

On Mon, Sep 28, 2020 at 03:14:23PM -0700, Randy Witt wrote:
> With the addition of the oslat test in v1.9, "make" with no arguments will
> fail on any architecture that isn't x86_64, i386 or PPC64. This is due to
> the #error added here https://git.kernel.org/pub/scm/utils/rt-tests/rt-tests.git/tree/src/oslat/oslat.c?h=v1.9#n72.
> 
> Since there is no build time configuration to turn off particular tests, is
> the expected workflow to specify the set of desired tests as make arguments?
> 
> In the absence of some sort of configure script, should there be a variable
> that allows for tests to be removed from the set of TARGETS?

I think we can, but instead of maintaining this knowledge both in the build
system and in oslat.c, I'm thinking maybe we can simply do that in oslat.c, let
it build but dump an error message for any unsupported archs.  Patch attached.

Another solution (as mentioned by John offlist) is we implement a common frc()
like fetching the time.  However since the __measure_cpu_hz() will always try
to calculate the cpu HZ, then the HZ could be confusing then.  Considering the
"read the processor clock" operation should still be the ideal implementation
for frc() (and I really doubt whether there'll be real need to run oslat on
other archs...), maybe we can use the simple way for now.

What do you think?

Thanks,

-- 
Peter Xu