Re: [PATCH v2] RFC perf test 14 add platform dependency

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Tue, Jun 20, 2017 at 04:06:15PM +0200, Thomas-Mich Richter escreveu:
> On 06/20/2017 11:24 AM, Jiri Olsa wrote:
> > On Tue, Jun 20, 2017 at 10:12:14AM +0200, Thomas-Mich Richter wrote:
> >> On 06/20/2017 03:40 AM, Arnaldo Carvalho de Melo wrote:
> >>> Em Mon, Jun 19, 2017 at 10:59:44PM +0200, Jiri Olsa escreveu:
> >>>> On Tue, Jun 13, 2017 at 11:09:37AM +0200, Thomas Richter wrote:
> >>>>> This is a proposal to add platform dependency into the
> >>>>> test case 14 (perf_event_attr). It is based on a suggestion from
> >>>>> Jiri Olsa.
> >>>>> Add a new optional attribute named 'machine' in the [config] section
> >>>>> of the test case file. It is a comma separated list of architecture
> >>>>> names this test can be executed on. For example:
> >>>>>
> >>>>> machine = x86_64,alpha,ppc
> >>>>
> >>>> 'arch' sounds better to me, but machine is ok I guess
> >>>
> >>> Agreed, for consistency with other places, like in struct machine, that
> >>> represents virtual and host 'machines' that have an 'arch', etc.
> >>>
> >>> So better to rename "machine" above to "arch".
> >>>
> >>
> >> Ok lets rename it to arch.
> >>
> >>>>> If this attribute is missing the test is executed on any platform.
> >>>>> This does not break the current setup.
> >>>>> The values listed for this attribute should be identical to
> >>>>> uname -m output.
> >>>>> If the list starts with an exclamation mark (!) the comparison is
> >>>>> inverted, for example for
> >>>>>
> >>>>> machine = !s390x,ppc
> >>>>>
> >>>>> the test is not executed on s390x or ppc platforms.
> >>>>> The exclamation mark must be at the beginnning of the list.
> >>>>
> >>>> could that be per arch? this made me think that it's not s390 and it IS for ppc
> >>>
> >>> yeah, having the ! affect just the arch right after it looks more
> >>> flexible and clear.
> >>>
> >>
> >> Does this really have any benefit? Assume
> >> arch = !s390x,ppc
> >>
> >> I will scan the list from left to right and the first match wins.
> >> Checking the first word in the list determines
> >> this test is executed on anything but s390x. So the 2nd word in the
> >> list (ppc) is useless. Specifying more architectures makes only sense
> >> when you negate them such as
> >> arch = !s390x,!ppc
> > 
> > ok, makes sense
> > 
> > thanks,
> > jirka
> > 
> 
> I will rewrite the patch for Linux 4.12 as soon as Arnaldo agrees 
> with us.

Yeah, that was me wanting this to have the same syntax as 'perf script
-F', where we start with a default list of fields and it makes sense to
ask for fields to be removed and, at the same time, for some other
fields to be added.

Here this is not the case, we start with: all arches, then we want to
remove some, so just having it at the start, as you did, is the right
thing, duh.

Sorry for the noise...

- Arnaldo