Re: Intermittent perf build failures

[Jiri Olsa]

On Sun, Oct 16, 2016 at 09:14:45AM +0200, Ingo Molnar wrote:
> 
> * Laura Abbott <labbott@xxxxxxxxxx> 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'.
> 

ok, will check on that

jirka