Re: Intermittent perf build failures

[Ingo Molnar <mingo@kernel.org>]

* Laura Abbott <labbott@redhat.com> wrote:

> On 10/12/2016 03:12 AM, Jiri Olsa wrote:
> >On Tue, Oct 11, 2016 at 02:18:49PM -0700, Laura Abbott wrote:
> >>On 10/11/2016 01:59 PM, Jiri Olsa wrote:
> >>>On Tue, Oct 11, 2016 at 01:43:36PM -0700, Laura Abbott wrote:
> >>>>Hi,
> >>>>
> >>>>While building today's Fedora rawhide kernel, there was a failure
> >>>>building perf with -j4 [1]:
> >
> >ok, the -j 4 is the problem
> >
> >running "make -j 4  install-bin install-traceevent-plugins"
> >
> >  BUILD:   Doing 'make -j4' parallel build
> >  BUILD:   Doing 'make -j4' parallel build
> >
> >will run paralel make instances for install-bin and install-traceevent-plugins
> >which will eventually touch same files and crash..
> >
> >the main perf Makefile is actualy detecting number of cpus
> >and runs Makefile.perf with -j X option so there's no need
> >to specify it on top level.. you can always customize it via
> >JOBS=X make variable
> >
> >so if you don't specify the -j X option it will run the
> >'Makefile.perf install-bin install-traceevent-plugins' with
> >-j X set and it should execute sequentialy and fix your problem
> >
> 
> Thanks for pointing that out. The build command has been there
> a while and apparently has bit rotted. I've removed the extra
> -j X flags from the command.

It would also be nice to fix the underlying perf build system problem as well: it 
should be entirely fine for people to type 'make -j4'.

Thanks,

	Ingo